/* * linux/fs/ext4/inode.c * * Copyright (C) 1992, 1993, 1994, 1995 * Remy Card (card@masi.ibp.fr) * Laboratoire MASI - Institut Blaise Pascal * Universite Pierre et Marie Curie (Paris VI) * * from * * linux/fs/minix/inode.c * * Copyright (C) 1991, 1992 Linus Torvalds * * 64-bit file support on 64-bit platforms by Jakub Jelinek * (jj@sunsite.ms.mff.cuni.cz) * * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ext4_jbd2.h" #include "xattr.h" #include "acl.h" #include "truncate.h" #include #define MPAGE_DA_EXTENT_TAIL 0x01 static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw, struct ext4_inode_info *ei) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); __u16 csum_lo; __u16 csum_hi = 0; __u32 csum; csum_lo = le16_to_cpu(raw->i_checksum_lo); raw->i_checksum_lo = 0; if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) { csum_hi = le16_to_cpu(raw->i_checksum_hi); raw->i_checksum_hi = 0; } csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw, EXT4_INODE_SIZE(inode->i_sb)); raw->i_checksum_lo = cpu_to_le16(csum_lo); if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) raw->i_checksum_hi = cpu_to_le16(csum_hi); return csum; } static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw, struct ext4_inode_info *ei) { __u32 provided, calculated; if (EXT4_SB(inode->i_sb)->s_es->s_creator_os != cpu_to_le32(EXT4_OS_LINUX) || !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) return 1; provided = le16_to_cpu(raw->i_checksum_lo); calculated = ext4_inode_csum(inode, raw, ei); if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16; else calculated &= 0xFFFF; return provided == calculated; } static void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw, struct ext4_inode_info *ei) { __u32 csum; if (EXT4_SB(inode->i_sb)->s_es->s_creator_os != cpu_to_le32(EXT4_OS_LINUX) || !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) return; csum = ext4_inode_csum(inode, raw, ei); raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF); if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) raw->i_checksum_hi = cpu_to_le16(csum >> 16); } static inline int ext4_begin_ordered_truncate(struct inode *inode, loff_t new_size) { trace_ext4_begin_ordered_truncate(inode, new_size); /* * If jinode is zero, then we never opened the file for * writing, so there's no need to call * jbd2_journal_begin_ordered_truncate() since there's no * outstanding writes we need to flush. */ if (!EXT4_I(inode)->jinode) return 0; return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode), EXT4_I(inode)->jinode, new_size); } static void ext4_invalidatepage(struct page *page, unsigned int offset, unsigned int length); static int __ext4_journalled_writepage(struct page *page, unsigned int len); static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh); static int ext4_meta_trans_blocks(struct inode *inode, int lblocks, int pextents); /* * Test whether an inode is a fast symlink. */ static int ext4_inode_is_fast_symlink(struct inode *inode) { int ea_blocks = EXT4_I(inode)->i_file_acl ? (inode->i_sb->s_blocksize >> 9) : 0; return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0); } /* * Restart the transaction associated with *handle. This does a commit, * so before we call here everything must be consistently dirtied against * this transaction. */ int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode, int nblocks) { int ret; /* * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this * moment, get_block can be called only for blocks inside i_size since * page cache has been already dropped and writes are blocked by * i_mutex. So we can safely drop the i_data_sem here. */ BUG_ON(EXT4_JOURNAL(inode) == NULL); jbd_debug(2, "restarting handle %p\n", handle); up_write(&EXT4_I(inode)->i_data_sem); ret = ext4_journal_restart(handle, nblocks); down_write(&EXT4_I(inode)->i_data_sem); ext4_discard_preallocations(inode); return ret; } /* * Called at the last iput() if i_nlink is zero. */ void ext4_evict_inode(struct inode *inode) { handle_t *handle; int err; trace_ext4_evict_inode(inode); if (inode->i_nlink) { /* * When journalling data dirty buffers are tracked only in the * journal. So although mm thinks everything is clean and * ready for reaping the inode might still have some pages to * write in the running transaction or waiting to be * checkpointed. Thus calling jbd2_journal_invalidatepage() * (via truncate_inode_pages()) to discard these buffers can * cause data loss. Also even if we did not discard these * buffers, we would have no way to find them after the inode * is reaped and thus user could see stale data if he tries to * read them before the transaction is checkpointed. So be * careful and force everything to disk here... We use * ei->i_datasync_tid to store the newest transaction * containing inode's data. * * Note that directories do not have this problem because they * don't use page cache. */ if (ext4_should_journal_data(inode) && (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode)) && inode->i_ino != EXT4_JOURNAL_INO) { journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; tid_t commit_tid = EXT4_I(inode)->i_datasync_tid; jbd2_complete_transaction(journal, commit_tid); filemap_write_and_wait(&inode->i_data); } truncate_inode_pages(&inode->i_data, 0); WARN_ON(atomic_read(&EXT4_I(inode)->i_ioend_count)); goto no_delete; } if (!is_bad_inode(inode)) dquot_initialize(inode); if (ext4_should_order_data(inode)) ext4_begin_ordered_truncate(inode, 0); truncate_inode_pages(&inode->i_data, 0); WARN_ON(atomic_read(&EXT4_I(inode)->i_ioend_count)); if (is_bad_inode(inode)) goto no_delete; /* * Protect us against freezing - iput() caller didn't have to have any * protection against it */ sb_start_intwrite(inode->i_sb); handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, ext4_blocks_for_truncate(inode)+3); if (IS_ERR(handle)) { ext4_std_error(inode->i_sb, PTR_ERR(handle)); /* * If we're going to skip the normal cleanup, we still need to * make sure that the in-core orphan linked list is properly * cleaned up. */ ext4_orphan_del(NULL, inode); sb_end_intwrite(inode->i_sb); goto no_delete; } if (IS_SYNC(inode)) ext4_handle_sync(handle); inode->i_size = 0; err = ext4_mark_inode_dirty(handle, inode); if (err) { ext4_warning(inode->i_sb, "couldn't mark inode dirty (err %d)", err); goto stop_handle; } if (inode->i_blocks) ext4_truncate(inode); /* * ext4_ext_truncate() doesn't reserve any slop when it * restarts journal transactions; therefore there may not be * enough credits left in the handle to remove the inode from * the orphan list and set the dtime field. */ if (!ext4_handle_has_enough_credits(handle, 3)) { err = ext4_journal_extend(handle, 3); if (err > 0) err = ext4_journal_restart(handle, 3); if (err != 0) { ext4_warning(inode->i_sb, "couldn't extend journal (err %d)", err); stop_handle: ext4_journal_stop(handle); ext4_orphan_del(NULL, inode); sb_end_intwrite(inode->i_sb); goto no_delete; } } /* * Kill off the orphan record which ext4_truncate created. * AKPM: I think this can be inside the above `if'. * Note that ext4_orphan_del() has to be able to cope with the * deletion of a non-existent orphan - this is because we don't * know if ext4_truncate() actually created an orphan record. * (Well, we could do this if we need to, but heck - it works) */ ext4_orphan_del(handle, inode); EXT4_I(inode)->i_dtime = get_seconds(); /* * One subtle ordering requirement: if anything has gone wrong * (transaction abort, IO errors, whatever), then we can still * do these next steps (the fs will already have been marked as * having errors), but we can't free the inode if the mark_dirty * fails. */ if (ext4_mark_inode_dirty(handle, inode)) /* If that failed, just do the required in-core inode clear. */ ext4_clear_inode(inode); else ext4_free_inode(handle, inode); ext4_journal_stop(handle); sb_end_intwrite(inode->i_sb); return; no_delete: ext4_clear_inode(inode); /* We must guarantee clearing of inode... */ } #ifdef CONFIG_QUOTA qsize_t *ext4_get_reserved_space(struct inode *inode) { return &EXT4_I(inode)->i_reserved_quota; } #endif /* * Calculate the number of metadata blocks need to reserve * to allocate a block located at @lblock */ static int ext4_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock) { if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) return ext4_ext_calc_metadata_amount(inode, lblock); return ext4_ind_calc_metadata_amount(inode, lblock); } /* * Called with i_data_sem down, which is important since we can call * ext4_discard_preallocations() from here. */ void ext4_da_update_reserve_space(struct inode *inode, int used, int quota_claim) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct ext4_inode_info *ei = EXT4_I(inode); spin_lock(&ei->i_block_reservation_lock); trace_ext4_da_update_reserve_space(inode, used, quota_claim); if (unlikely(used > ei->i_reserved_data_blocks)) { ext4_warning(inode->i_sb, "%s: ino %lu, used %d " "with only %d reserved data blocks", __func__, inode->i_ino, used, ei->i_reserved_data_blocks); WARN_ON(1); used = ei->i_reserved_data_blocks; } if (unlikely(ei->i_allocated_meta_blocks > ei->i_reserved_meta_blocks)) { ext4_warning(inode->i_sb, "ino %lu, allocated %d " "with only %d reserved metadata blocks " "(releasing %d blocks with reserved %d data blocks)", inode->i_ino, ei->i_allocated_meta_blocks, ei->i_reserved_meta_blocks, used, ei->i_reserved_data_blocks); WARN_ON(1); ei->i_allocated_meta_blocks = ei->i_reserved_meta_blocks; } /* Update per-inode reservations */ ei->i_reserved_data_blocks -= used; ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks; percpu_counter_sub(&sbi->s_dirtyclusters_counter, used + ei->i_allocated_meta_blocks); ei->i_allocated_meta_blocks = 0; if (ei->i_reserved_data_blocks == 0) { /* * We can release all of the reserved metadata blocks * only when we have written all of the delayed * allocation blocks. */ percpu_counter_sub(&sbi->s_dirtyclusters_counter, ei->i_reserved_meta_blocks); ei->i_reserved_meta_blocks = 0; ei->i_da_metadata_calc_len = 0; } spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); /* Update quota subsystem for data blocks */ if (quota_claim) dquot_claim_block(inode, EXT4_C2B(sbi, used)); else { /* * We did fallocate with an offset that is already delayed * allocated. So on delayed allocated writeback we should * not re-claim the quota for fallocated blocks. */ dquot_release_reservation_block(inode, EXT4_C2B(sbi, used)); } /* * If we have done all the pending block allocations and if * there aren't any writers on the inode, we can discard the * inode's preallocations. */ if ((ei->i_reserved_data_blocks == 0) && (atomic_read(&inode->i_writecount) == 0)) ext4_discard_preallocations(inode); } static int __check_block_validity(struct inode *inode, const char *func, unsigned int line, struct ext4_map_blocks *map) { if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk, map->m_len)) { ext4_error_inode(inode, func, line, map->m_pblk, "lblock %lu mapped to illegal pblock " "(length %d)", (unsigned long) map->m_lblk, map->m_len); return -EIO; } return 0; } #define check_block_validity(inode, map) \ __check_block_validity((inode), __func__, __LINE__, (map)) #ifdef ES_AGGRESSIVE_TEST static void ext4_map_blocks_es_recheck(handle_t *handle, struct inode *inode, struct ext4_map_blocks *es_map, struct ext4_map_blocks *map, int flags) { int retval; map->m_flags = 0; /* * There is a race window that the result is not the same. * e.g. xfstests #223 when dioread_nolock enables. The reason * is that we lookup a block mapping in extent status tree with * out taking i_data_sem. So at the time the unwritten extent * could be converted. */ if (!(flags & EXT4_GET_BLOCKS_NO_LOCK)) down_read((&EXT4_I(inode)->i_data_sem)); if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { retval = ext4_ext_map_blocks(handle, inode, map, flags & EXT4_GET_BLOCKS_KEEP_SIZE); } else { retval = ext4_ind_map_blocks(handle, inode, map, flags & EXT4_GET_BLOCKS_KEEP_SIZE); } if (!(flags & EXT4_GET_BLOCKS_NO_LOCK)) up_read((&EXT4_I(inode)->i_data_sem)); /* * Clear EXT4_MAP_FROM_CLUSTER and EXT4_MAP_BOUNDARY flag * because it shouldn't be marked in es_map->m_flags. */ map->m_flags &= ~(EXT4_MAP_FROM_CLUSTER | EXT4_MAP_BOUNDARY); /* * We don't check m_len because extent will be collpased in status * tree. So the m_len might not equal. */ if (es_map->m_lblk != map->m_lblk || es_map->m_flags != map->m_flags || es_map->m_pblk != map->m_pblk) { printk("ES cache assertion failed for inode: %lu " "es_cached ex [%d/%d/%llu/%x] != " "found ex [%d/%d/%llu/%x] retval %d flags %x\n", inode->i_ino, es_map->m_lblk, es_map->m_len, es_map->m_pblk, es_map->m_flags, map->m_lblk, map->m_len, map->m_pblk, map->m_flags, retval, flags); } } #endif /* ES_AGGRESSIVE_TEST */ /* * The ext4_map_blocks() function tries to look up the requested blocks, * and returns if the blocks are already mapped. * * Otherwise it takes the write lock of the i_data_sem and allocate blocks * and store the allocated blocks in the result buffer head and mark it * mapped. * * If file type is extents based, it will call ext4_ext_map_blocks(), * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping * based files * * On success, it returns the number of blocks being mapped or allocate. * if create==0 and the blocks are pre-allocated and uninitialized block, * the result buffer head is unmapped. If the create ==1, it will make sure * the buffer head is mapped. * * It returns 0 if plain look up failed (blocks have not been allocated), in * that case, buffer head is unmapped * * It returns the error in case of allocation failure. */ int ext4_map_blocks(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, int flags) { struct extent_status es; int retval; #ifdef ES_AGGRESSIVE_TEST struct ext4_map_blocks orig_map; memcpy(&orig_map, map, sizeof(*map)); #endif map->m_flags = 0; ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u," "logical block %lu\n", inode->i_ino, flags, map->m_len, (unsigned long) map->m_lblk); /* Lookup extent status tree firstly */ if (ext4_es_lookup_extent(inode, map->m_lblk, &es)) { ext4_es_lru_add(inode); if (ext4_es_is_written(&es) || ext4_es_is_unwritten(&es)) { map->m_pblk = ext4_es_pblock(&es) + map->m_lblk - es.es_lblk; map->m_flags |= ext4_es_is_written(&es) ? EXT4_MAP_MAPPED : EXT4_MAP_UNWRITTEN; retval = es.es_len - (map->m_lblk - es.es_lblk); if (retval > map->m_len) retval = map->m_len; map->m_len = retval; } else if (ext4_es_is_delayed(&es) || ext4_es_is_hole(&es)) { retval = 0; } else { BUG_ON(1); } #ifdef ES_AGGRESSIVE_TEST ext4_map_blocks_es_recheck(handle, inode, map, &orig_map, flags); #endif goto found; } /* * Try to see if we can get the block without requesting a new * file system block. */ if (!(flags & EXT4_GET_BLOCKS_NO_LOCK)) down_read((&EXT4_I(inode)->i_data_sem)); if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { retval = ext4_ext_map_blocks(handle, inode, map, flags & EXT4_GET_BLOCKS_KEEP_SIZE); } else { retval = ext4_ind_map_blocks(handle, inode, map, flags & EXT4_GET_BLOCKS_KEEP_SIZE); } if (retval > 0) { int ret; unsigned long long status; if (unlikely(retval != map->m_len)) { ext4_warning(inode->i_sb, "ES len assertion failed for inode " "%lu: retval %d != map->m_len %d", inode->i_ino, retval, map->m_len); WARN_ON(1); } status = map->m_flags & EXT4_MAP_UNWRITTEN ? EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN; if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) && ext4_find_delalloc_range(inode, map->m_lblk, map->m_lblk + map->m_len - 1)) status |= EXTENT_STATUS_DELAYED; ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, map->m_pblk, status); if (ret < 0) retval = ret; } if (!(flags & EXT4_GET_BLOCKS_NO_LOCK)) up_read((&EXT4_I(inode)->i_data_sem)); found: if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) { int ret = check_block_validity(inode, map); if (ret != 0) return ret; } /* If it is only a block(s) look up */ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) return retval; /* * Returns if the blocks have already allocated * * Note that if blocks have been preallocated * ext4_ext_get_block() returns the create = 0 * with buffer head unmapped. */ if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) return retval; /* * Here we clear m_flags because after allocating an new extent, * it will be set again. */ map->m_flags &= ~EXT4_MAP_FLAGS; /* * New blocks allocate and/or writing to uninitialized extent * will possibly result in updating i_data, so we take * the write lock of i_data_sem, and call get_blocks() * with create == 1 flag. */ down_write((&EXT4_I(inode)->i_data_sem)); /* * if the caller is from delayed allocation writeout path * we have already reserved fs blocks for allocation * let the underlying get_block() function know to * avoid double accounting */ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) ext4_set_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED); /* * We need to check for EXT4 here because migrate * could have changed the inode type in between */ if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { retval = ext4_ext_map_blocks(handle, inode, map, flags); } else { retval = ext4_ind_map_blocks(handle, inode, map, flags); if (retval > 0 && map->m_flags & EXT4_MAP_NEW) { /* * We allocated new blocks which will result in * i_data's format changing. Force the migrate * to fail by clearing migrate flags */ ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE); } /* * Update reserved blocks/metadata blocks after successful * block allocation which had been deferred till now. We don't * support fallocate for non extent files. So we can update * reserve space here. */ if ((retval > 0) && (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)) ext4_da_update_reserve_space(inode, retval, 1); } if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED); if (retval > 0) { int ret; unsigned long long status; if (unlikely(retval != map->m_len)) { ext4_warning(inode->i_sb, "ES len assertion failed for inode " "%lu: retval %d != map->m_len %d", inode->i_ino, retval, map->m_len); WARN_ON(1); } /* * If the extent has been zeroed out, we don't need to update * extent status tree. */ if ((flags & EXT4_GET_BLOCKS_PRE_IO) && ext4_es_lookup_extent(inode, map->m_lblk, &es)) { if (ext4_es_is_written(&es)) goto has_zeroout; } status = map->m_flags & EXT4_MAP_UNWRITTEN ? EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN; if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) && ext4_find_delalloc_range(inode, map->m_lblk, map->m_lblk + map->m_len - 1)) status |= EXTENT_STATUS_DELAYED; ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, map->m_pblk, status); if (ret < 0) retval = ret; } has_zeroout: up_write((&EXT4_I(inode)->i_data_sem)); if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) { int ret = check_block_validity(inode, map); if (ret != 0) return ret; } return retval; } /* Maximum number of blocks we map for direct IO at once. */ #define DIO_MAX_BLOCKS 4096 static int _ext4_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh, int flags) { handle_t *handle = ext4_journal_current_handle(); struct ext4_map_blocks map; int ret = 0, started = 0; int dio_credits; if (ext4_has_inline_data(inode)) return -ERANGE; map.m_lblk = iblock; map.m_len = bh->b_size >> inode->i_blkbits; if (flags && !(flags & EXT4_GET_BLOCKS_NO_LOCK) && !handle) { /* Direct IO write... */ if (map.m_len > DIO_MAX_BLOCKS) map.m_len = DIO_MAX_BLOCKS; dio_credits = ext4_chunk_trans_blocks(inode, map.m_len); handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits); if (IS_ERR(handle)) { ret = PTR_ERR(handle); return ret; } started = 1; } ret = ext4_map_blocks(handle, inode, &map, flags); if (ret > 0) { ext4_io_end_t *io_end = ext4_inode_aio(inode); map_bh(bh, inode->i_sb, map.m_pblk); bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags; if (io_end && io_end->flag & EXT4_IO_END_UNWRITTEN) set_buffer_defer_completion(bh); bh->b_size = inode->i_sb->s_blocksize * map.m_len; ret = 0; } if (started) ext4_journal_stop(handle); return ret; } int ext4_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh, int create) { return _ext4_get_block(inode, iblock, bh, create ? EXT4_GET_BLOCKS_CREATE : 0); } /* * `handle' can be NULL if create is zero */ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode, ext4_lblk_t block, int create, int *errp) { struct ext4_map_blocks map; struct buffer_head *bh; int fatal = 0, err; J_ASSERT(handle != NULL || create == 0); map.m_lblk = block; map.m_len = 1; err = ext4_map_blocks(handle, inode, &map, create ? EXT4_GET_BLOCKS_CREATE : 0); /* ensure we send some value back into *errp */ *errp = 0; if (create && err == 0) err = -ENOSPC; /* should never happen */ if (err < 0) *errp = err; if (err <= 0) return NULL; bh = sb_getblk(inode->i_sb, map.m_pblk); if (unlikely(!bh)) { *errp = -ENOMEM; return NULL; } if (map.m_flags & EXT4_MAP_NEW) { J_ASSERT(create != 0); J_ASSERT(handle != NULL); /* * Now that we do not always journal data, we should * keep in mind whether this should always journal the * new buffer as metadata. For now, regular file * writes use ext4_get_block instead, so it's not a * problem. */ lock_buffer(bh); BUFFER_TRACE(bh, "call get_create_access"); fatal = ext4_journal_get_create_access(handle, bh); if (!fatal && !buffer_uptodate(bh)) { memset(bh->b_data, 0, inode->i_sb->s_blocksize); set_buffer_uptodate(bh); } unlock_buffer(bh); BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_metadata(handle, inode, bh); if (!fatal) fatal = err; } else { BUFFER_TRACE(bh, "not a new buffer"); } if (fatal) { *errp = fatal; brelse(bh); bh = NULL; } return bh; } struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode, ext4_lblk_t block, int create, int *err) { struct buffer_head *bh; bh = ext4_getblk(handle, inode, block, create, err); if (!bh) return bh; if (buffer_uptodate(bh)) return bh; ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh); wait_on_buffer(bh); if (buffer_uptodate(bh)) return bh; put_bh(bh); *err = -EIO; return NULL; } int ext4_walk_page_buffers(handle_t *handle, struct buffer_head *head, unsigned from, unsigned to, int *partial, int (*fn)(handle_t *handle, struct buffer_head *bh)) { struct buffer_head *bh; unsigned block_start, block_end; unsigned blocksize = head->b_size; int err, ret = 0; struct buffer_head *next; for (bh = head, block_start = 0; ret == 0 && (bh != head || !block_start); block_start = block_end, bh = next) { next = bh->b_this_page; block_end = block_start + blocksize; if (block_end <= from || block_start >= to) { if (partial && !buffer_uptodate(bh)) *partial = 1; continue; } err = (*fn)(handle, bh); if (!ret) ret = err; } return ret; } /* * To preserve ordering, it is essential that the hole instantiation and * the data write be encapsulated in a single transaction. We cannot * close off a transaction and start a new one between the ext4_get_block() * and the commit_write(). So doing the jbd2_journal_start at the start of * prepare_write() is the right place. * * Also, this function can nest inside ext4_writepage(). In that case, we * *know* that ext4_writepage() has generated enough buffer credits to do the * whole page. So we won't block on the journal in that case, which is good, * because the caller may be PF_MEMALLOC. * * By accident, ext4 can be reentered when a transaction is open via * quota file writes. If we were to commit the transaction while thus * reentered, there can be a deadlock - we would be holding a quota * lock, and the commit would never complete if another thread had a * transaction open and was blocking on the quota lock - a ranking * violation. * * So what we do is to rely on the fact that jbd2_journal_stop/journal_start * will _not_ run commit under these circumstances because handle->h_ref * is elevated. We'll still have enough credits for the tiny quotafile * write. */ int do_journal_get_write_access(handle_t *handle, struct buffer_head *bh) { int dirty = buffer_dirty(bh); int ret; if (!buffer_mapped(bh) || buffer_freed(bh)) return 0; /* * __block_write_begin() could have dirtied some buffers. Clean * the dirty bit as jbd2_journal_get_write_access() could complain * otherwise about fs integrity issues. Setting of the dirty bit * by __block_write_begin() isn't a real problem here as we clear * the bit before releasing a page lock and thus writeback cannot * ever write the buffer. */ if (dirty) clear_buffer_dirty(bh); ret = ext4_journal_get_write_access(handle, bh); if (!ret && dirty) ret = ext4_handle_dirty_metadata(handle, NULL, bh); return ret; } static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create); static int ext4_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata) { struct inode *inode = mapping->host; int ret, needed_blocks; handle_t *handle; int retries = 0; struct page *page; pgoff_t index; unsigned from, to; trace_ext4_write_begin(inode, pos, len, flags); /* * Reserve one block more for addition to orphan list in case * we allocate blocks but write fails for some reason */ needed_blocks = ext4_writepage_trans_blocks(inode) + 1; index = pos >> PAGE_CACHE_SHIFT; from = pos & (PAGE_CACHE_SIZE - 1); to = from + len; if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { ret = ext4_try_to_write_inline_data(mapping, inode, pos, len, flags, pagep); if (ret < 0) return ret; if (ret == 1) return 0; } /* * grab_cache_page_write_begin() can take a long time if the * system is thrashing due to memory pressure, or if the page * is being written back. So grab it first before we start * the transaction handle. This also allows us to allocate * the page (if needed) without using GFP_NOFS. */ retry_grab: page = grab_cache_page_write_begin(mapping, index, flags); if (!page) return -ENOMEM; unlock_page(page); retry_journal: handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks); if (IS_ERR(handle)) { page_cache_release(page); return PTR_ERR(handle); } lock_page(page); if (page->mapping != mapping) { /* The page got truncated from under us */ unlock_page(page); page_cache_release(page); ext4_journal_stop(handle); goto retry_grab; } wait_on_page_writeback(page); if (ext4_should_dioread_nolock(inode)) ret = __block_write_begin(page, pos, len, ext4_get_block_write); else ret = __block_write_begin(page, pos, len, ext4_get_block); if (!ret && ext4_should_journal_data(inode)) { ret = ext4_walk_page_buffers(handle, page_buffers(page), from, to, NULL, do_journal_get_write_access); } if (ret) { unlock_page(page); /* * __block_write_begin may have instantiated a few blocks * outside i_size. Trim these off again. Don't need * i_size_read because we hold i_mutex. * * Add inode to orphan list in case we crash before * truncate finishes */ if (pos + len > inode->i_size && ext4_can_truncate(inode)) ext4_orphan_add(handle, inode); ext4_journal_stop(handle); if (pos + len > inode->i_size) { ext4_truncate_failed_write(inode); /* * If truncate failed early the inode might * still be on the orphan list; we need to * make sure the inode is removed from the * orphan list in that case. */ if (inode->i_nlink) ext4_orphan_del(NULL, inode); } if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) goto retry_journal; page_cache_release(page); return ret; } *pagep = page; return ret; } /* For write_end() in data=journal mode */ static int write_end_fn(handle_t *handle, struct buffer_head *bh) { int ret; if (!buffer_mapped(bh) || buffer_freed(bh)) return 0; set_buffer_uptodate(bh); ret = ext4_handle_dirty_metadata(handle, NULL, bh); clear_buffer_meta(bh); clear_buffer_prio(bh); return ret; } /* * We need to pick up the new inode size which generic_commit_write gave us * `file' can be NULL - eg, when called from page_symlink(). * * ext4 never places buffers on inode->i_mapping->private_list. metadata * buffers are managed internally. */ static int ext4_write_end(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned copied, struct page *page, void *fsdata) { handle_t *handle = ext4_journal_current_handle(); struct inode *inode = mapping->host; int ret = 0, ret2; int i_size_changed = 0; trace_ext4_write_end(inode, pos, len, copied); if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE)) { ret = ext4_jbd2_file_inode(handle, inode); if (ret) { unlock_page(page); page_cache_release(page); goto errout; } } if (ext4_has_inline_data(inode)) { ret = ext4_write_inline_data_end(inode, pos, len, copied, page); if (ret < 0) goto errout; copied = ret; } else copied = block_write_end(file, mapping, pos, len, copied, page, fsdata); /* * No need to use i_size_read() here, the i_size * cannot change under us because we hole i_mutex. * * But it's important to update i_size while still holding page lock: * page writeout could otherwise come in and zero beyond i_size. */ if (pos + copied > inode->i_size) { i_size_write(inode, pos + copied); i_size_changed = 1; } if (pos + copied > EXT4_I(inode)->i_disksize) { /* We need to mark inode dirty even if * new_i_size is less that inode->i_size * but greater than i_disksize. (hint delalloc) */ ext4_update_i_disksize(inode, (pos + copied)); i_size_changed = 1; } unlock_page(page); page_cache_release(page); /* * Don't mark the inode dirty under page lock. First, it unnecessarily * makes the holding time of page lock longer. Second, it forces lock * ordering of page lock and transaction start for journaling * filesystems. */ if (i_size_changed) ext4_mark_inode_dirty(handle, inode); if (pos + len > inode->i_size && ext4_can_truncate(inode)) /* if we have allocated more blocks and copied * less. We will have blocks allocated outside * inode->i_size. So truncate them */ ext4_orphan_add(handle, inode); errout: ret2 = ext4_journal_stop(handle); if (!ret) ret = ret2; if (pos + len > inode->i_size) { ext4_truncate_failed_write(inode); /* * If truncate failed early the inode might still be * on the orphan list; we need to make sure the inode * is removed from the orphan list in that case. */ if (inode->i_nlink) ext4_orphan_del(NULL, inode); } return ret ? ret : copied; } static int ext4_journalled_write_end(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned copied, struct page *page, void *fsdata) { handle_t *handle = ext4_journal_current_handle(); struct inode *inode = mapping->host; int ret = 0, ret2; int partial = 0; unsigned from, to; loff_t new_i_size; trace_ext4_journalled_write_end(inode, pos, len, copied); from = pos & (PAGE_CACHE_SIZE - 1); to = from + len; BUG_ON(!ext4_handle_valid(handle)); if (ext4_has_inline_data(inode)) copied = ext4_write_inline_data_end(inode, pos, len, copied, page); else { if (copied < len) { if (!PageUptodate(page)) copied = 0; page_zero_new_buffers(page, from+copied, to); } ret = ext4_walk_page_buffers(handle, page_buffers(page), from, to, &partial, write_end_fn); if (!partial) SetPageUptodate(page); } new_i_size = pos + copied; if (new_i_size > inode->i_size) i_size_write(inode, pos+copied); ext4_set_inode_state(inode, EXT4_STATE_JDATA); EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid; if (new_i_size > EXT4_I(inode)->i_disksize) { ext4_update_i_disksize(inode, new_i_size); ret2 = ext4_mark_inode_dirty(handle, inode); if (!ret) ret = ret2; } unlock_page(page); page_cache_release(page); if (pos + len > inode->i_size && ext4_can_truncate(inode)) /* if we have allocated more blocks and copied * less. We will have blocks allocated outside * inode->i_size. So truncate them */ ext4_orphan_add(handle, inode); ret2 = ext4_journal_stop(handle); if (!ret) ret = ret2; if (pos + len > inode->i_size) { ext4_truncate_failed_write(inode); /* * If truncate failed early the inode might still be * on the orphan list; we need to make sure the inode * is removed from the orphan list in that case. */ if (inode->i_nlink) ext4_orphan_del(NULL, inode); } return ret ? ret : copied; } /* * Reserve a metadata for a single block located at lblock */ static int ext4_da_reserve_metadata(struct inode *inode, ext4_lblk_t lblock) { int retries = 0; struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct ext4_inode_info *ei = EXT4_I(inode); unsigned int md_needed; ext4_lblk_t save_last_lblock; int save_len; /* * recalculate the amount of metadata blocks to reserve * in order to allocate nrblocks * worse case is one extent per block */ repeat: spin_lock(&ei->i_block_reservation_lock); /* * ext4_calc_metadata_amount() has side effects, which we have * to be prepared undo if we fail to claim space. */ save_len = ei->i_da_metadata_calc_len; save_last_lblock = ei->i_da_metadata_calc_last_lblock; md_needed = EXT4_NUM_B2C(sbi, ext4_calc_metadata_amount(inode, lblock)); trace_ext4_da_reserve_space(inode, md_needed); /* * We do still charge estimated metadata to the sb though; * we cannot afford to run out of free blocks. */ if (ext4_claim_free_clusters(sbi, md_needed, 0)) { ei->i_da_metadata_calc_len = save_len; ei->i_da_metadata_calc_last_lblock = save_last_lblock; spin_unlock(&ei->i_block_reservation_lock); if (ext4_should_retry_alloc(inode->i_sb, &retries)) { cond_resched(); goto repeat; } return -ENOSPC; } ei->i_reserved_meta_blocks += md_needed; spin_unlock(&ei->i_block_reservation_lock); return 0; /* success */ } /* * Reserve a single cluster located at lblock */ static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock) { int retries = 0; struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct ext4_inode_info *ei = EXT4_I(inode); unsigned int md_needed; int ret; ext4_lblk_t save_last_lblock; int save_len; /* * We will charge metadata quota at writeout time; this saves * us from metadata over-estimation, though we may go over by * a small amount in the end. Here we just reserve for data. */ ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1)); if (ret) return ret; /* * recalculate the amount of metadata blocks to reserve * in order to allocate nrblocks * worse case is one extent per block */ repeat: spin_lock(&ei->i_block_reservation_lock); /* * ext4_calc_metadata_amount() has side effects, which we have * to be prepared undo if we fail to claim space. */ save_len = ei->i_da_metadata_calc_len; save_last_lblock = ei->i_da_metadata_calc_last_lblock; md_needed = EXT4_NUM_B2C(sbi, ext4_calc_metadata_amount(inode, lblock)); trace_ext4_da_reserve_space(inode, md_needed); /* * We do still charge estimated metadata to the sb though; * we cannot afford to run out of free blocks. */ if (ext4_claim_free_clusters(sbi, md_needed + 1, 0)) { ei->i_da_metadata_calc_len = save_len; ei->i_da_metadata_calc_last_lblock = save_last_lblock; spin_unlock(&ei->i_block_reservation_lock); if (ext4_should_retry_alloc(inode->i_sb, &retries)) { cond_resched(); goto repeat; } dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1)); return -ENOSPC; } ei->i_reserved_data_blocks++; ei->i_reserved_meta_blocks += md_needed; spin_unlock(&ei->i_block_reservation_lock); return 0; /* success */ } static void ext4_da_release_space(struct inode *inode, int to_free) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct ext4_inode_info *ei = EXT4_I(inode); if (!to_free) return; /* Nothing to release, exit */ spin_lock(&EXT4_I(inode)->i_block_reservation_lock); trace_ext4_da_release_space(inode, to_free); if (unlikely(to_free > ei->i_reserved_data_blocks)) { /* * if there aren't enough reserved blocks, then the * counter is messed up somewhere. Since this * function is called from invalidate page, it's * harmless to return without any action. */ ext4_warning(inode->i_sb, "ext4_da_release_space: " "ino %lu, to_free %d with only %d reserved " "data blocks", inode->i_ino, to_free, ei->i_reserved_data_blocks); WARN_ON(1); to_free = ei->i_reserved_data_blocks; } ei->i_reserved_data_blocks -= to_free; if (ei->i_reserved_data_blocks == 0) { /* * We can release all of the reserved metadata blocks * only when we have written all of the delayed * allocation blocks. * Note that in case of bigalloc, i_reserved_meta_blocks, * i_reserved_data_blocks, etc. refer to number of clusters. */ percpu_counter_sub(&sbi->s_dirtyclusters_counter, ei->i_reserved_meta_blocks); ei->i_reserved_meta_blocks = 0; ei->i_da_metadata_calc_len = 0; } /* update fs dirty data blocks counter */ percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free); spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free)); } static void ext4_da_page_release_reservation(struct page *page, unsigned int offset, unsigned int length) { int to_release = 0; struct buffer_head *head, *bh; unsigned int curr_off = 0; struct inode *inode = page->mapping->host; struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); unsigned int stop = offset + length; int num_clusters; ext4_fsblk_t lblk; BUG_ON(stop > PAGE_CACHE_SIZE || stop < length); head = page_buffers(page); bh = head; do { unsigned int next_off = curr_off + bh->b_size; if (next_off > stop) break; if ((offset <= curr_off) && (buffer_delay(bh))) { to_release++; clear_buffer_delay(bh); } curr_off = next_off; } while ((bh = bh->b_this_page) != head); if (to_release) { lblk = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits); ext4_es_remove_extent(inode, lblk, to_release); } /* If we have released all the blocks belonging to a cluster, then we * need to release the reserved space for that cluster. */ num_clusters = EXT4_NUM_B2C(sbi, to_release); while (num_clusters > 0) { lblk = (page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits)) + ((num_clusters - 1) << sbi->s_cluster_bits); if (sbi->s_cluster_ratio == 1 || !ext4_find_delalloc_cluster(inode, lblk)) ext4_da_release_space(inode, 1); num_clusters--; } } /* * Delayed allocation stuff */ struct mpage_da_data { struct inode *inode; struct writeback_control *wbc; pgoff_t first_page; /* The first page to write */ pgoff_t next_page; /* Current page to examine */ pgoff_t last_page; /* Last page to examine */ /* * Extent to map - this can be after first_page because that can be * fully mapped. We somewhat abuse m_flags to store whether the extent * is delalloc or unwritten. */ struct ext4_map_blocks map; struct ext4_io_submit io_submit; /* IO submission data */ }; static void mpage_release_unused_pages(struct mpage_da_data *mpd, bool invalidate) { int nr_pages, i; pgoff_t index, end; struct pagevec pvec; struct inode *inode = mpd->inode; struct address_space *mapping = inode->i_mapping; /* This is necessary when next_page == 0. */ if (mpd->first_page >= mpd->next_page) return; index = mpd->first_page; end = mpd->next_page - 1; if (invalidate) { ext4_lblk_t start, last; start = index << (PAGE_CACHE_SHIFT - inode->i_blkbits); last = end << (PAGE_CACHE_SHIFT - inode->i_blkbits); ext4_es_remove_extent(inode, start, last - start + 1); } pagevec_init(&pvec, 0); while (index <= end) { nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE); if (nr_pages == 0) break; for (i = 0; i < nr_pages; i++) { struct page *page = pvec.pages[i]; if (page->index > end) break; BUG_ON(!PageLocked(page)); BUG_ON(PageWriteback(page)); if (invalidate) { block_invalidatepage(page, 0, PAGE_CACHE_SIZE); ClearPageUptodate(page); } unlock_page(page); } index = pvec.pages[nr_pages - 1]->index + 1; pagevec_release(&pvec); } } static void ext4_print_free_blocks(struct inode *inode) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct super_block *sb = inode->i_sb; struct ext4_inode_info *ei = EXT4_I(inode); ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld", EXT4_C2B(EXT4_SB(inode->i_sb), ext4_count_free_clusters(sb))); ext4_msg(sb, KERN_CRIT, "Free/Dirty block details"); ext4_msg(sb, KERN_CRIT, "free_blocks=%lld", (long long) EXT4_C2B(EXT4_SB(sb), percpu_counter_sum(&sbi->s_freeclusters_counter))); ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld", (long long) EXT4_C2B(EXT4_SB(sb), percpu_counter_sum(&sbi->s_dirtyclusters_counter))); ext4_msg(sb, KERN_CRIT, "Block reservation details"); ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u", ei->i_reserved_data_blocks); ext4_msg(sb, KERN_CRIT, "i_reserved_meta_blocks=%u", ei->i_reserved_meta_blocks); ext4_msg(sb, KERN_CRIT, "i_allocated_meta_blocks=%u", ei->i_allocated_meta_blocks); return; } static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh) { return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh); } /* * This function is grabs code from the very beginning of * ext4_map_blocks, but assumes that the caller is from delayed write * time. This function looks up the requested blocks and sets the * buffer delay bit under the protection of i_data_sem. */ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock, struct ext4_map_blocks *map, struct buffer_head *bh) { struct extent_status es; int retval; sector_t invalid_block = ~((sector_t) 0xffff); #ifdef ES_AGGRESSIVE_TEST struct ext4_map_blocks orig_map; memcpy(&orig_map, map, sizeof(*map)); #endif if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es)) invalid_block = ~0; map->m_flags = 0; ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u," "logical block %lu\n", inode->i_ino, map->m_len, (unsigned long) map->m_lblk); /* Lookup extent status tree firstly */ if (ext4_es_lookup_extent(inode, iblock, &es)) { ext4_es_lru_add(inode); if (ext4_es_is_hole(&es)) { retval = 0; down_read((&EXT4_I(inode)->i_data_sem)); goto add_delayed; } /* * Delayed extent could be allocated by fallocate. * So we need to check it. */ if (ext4_es_is_delayed(&es) && !ext4_es_is_unwritten(&es)) { map_bh(bh, inode->i_sb, invalid_block); set_buffer_new(bh); set_buffer_delay(bh); return 0; } map->m_pblk = ext4_es_pblock(&es) + iblock - es.es_lblk; retval = es.es_len - (iblock - es.es_lblk); if (retval > map->m_len) retval = map->m_len; map->m_len = retval; if (ext4_es_is_written(&es)) map->m_flags |= EXT4_MAP_MAPPED; else if (ext4_es_is_unwritten(&es)) map->m_flags |= EXT4_MAP_UNWRITTEN; else BUG_ON(1); #ifdef ES_AGGRESSIVE_TEST ext4_map_blocks_es_recheck(NULL, inode, map, &orig_map, 0); #endif return retval; } /* * Try to see if we can get the block without requesting a new * file system block. */ down_read((&EXT4_I(inode)->i_data_sem)); if (ext4_has_inline_data(inode)) { /* * We will soon create blocks for this page, and let * us pretend as if the blocks aren't allocated yet. * In case of clusters, we have to handle the work * of mapping from cluster so that the reserved space * is calculated properly. */ if ((EXT4_SB(inode->i_sb)->s_cluster_ratio > 1) && ext4_find_delalloc_cluster(inode, map->m_lblk)) map->m_flags |= EXT4_MAP_FROM_CLUSTER; retval = 0; } else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) retval = ext4_ext_map_blocks(NULL, inode, map, EXT4_GET_BLOCKS_NO_PUT_HOLE); else retval = ext4_ind_map_blocks(NULL, inode, map, EXT4_GET_BLOCKS_NO_PUT_HOLE); add_delayed: if (retval == 0) { int ret; /* * XXX: __block_prepare_write() unmaps passed block, * is it OK? */ /* * If the block was allocated from previously allocated cluster, * then we don't need to reserve it again. However we still need * to reserve metadata for every block we're going to write. */ if (!(map->m_flags & EXT4_MAP_FROM_CLUSTER)) { ret = ext4_da_reserve_space(inode, iblock); if (ret) { /* not enough space to reserve */ retval = ret; goto out_unlock; } } else { ret = ext4_da_reserve_metadata(inode, iblock); if (ret) { /* not enough space to reserve */ retval = ret; goto out_unlock; } } ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, ~0, EXTENT_STATUS_DELAYED); if (ret) { retval = ret; goto out_unlock; } /* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served * and it should not appear on the bh->b_state. */ map->m_flags &= ~EXT4_MAP_FROM_CLUSTER; map_bh(bh, inode->i_sb, invalid_block); set_buffer_new(bh); set_buffer_delay(bh); } else if (retval > 0) { int ret; unsigned long long status; if (unlikely(retval != map->m_len)) { ext4_warning(inode->i_sb, "ES len assertion failed for inode " "%lu: retval %d != map->m_len %d", inode->i_ino, retval, map->m_len); WARN_ON(1); } status = map->m_flags & EXT4_MAP_UNWRITTEN ? EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN; ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, map->m_pblk, status); if (ret != 0) retval = ret; } out_unlock: up_read((&EXT4_I(inode)->i_data_sem)); return retval; } /* * This is a special get_blocks_t callback which is used by * ext4_da_write_begin(). It will either return mapped block or * reserve space for a single block. * * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set. * We also have b_blocknr = -1 and b_bdev initialized properly * * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set. * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev * initialized properly. */ int ext4_da_get_block_prep(struct inode *inode, sector_t iblock, struct buffer_head *bh, int create) { struct ext4_map_blocks map; int ret = 0; BUG_ON(create == 0); BUG_ON(bh->b_size != inode->i_sb->s_blocksize); map.m_lblk = iblock; map.m_len = 1; /* * first, we need to know whether the block is allocated already * preallocated blocks are unmapped but should treated * the same as allocated blocks. */ ret = ext4_da_map_blocks(inode, iblock, &map, bh); if (ret <= 0) return ret; map_bh(bh, inode->i_sb, map.m_pblk); bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags; if (buffer_unwritten(bh)) { /* A delayed write to unwritten bh should be marked * new and mapped. Mapped ensures that we don't do * get_block multiple times when we write to the same * offset and new ensures that we do proper zero out * for partial write. */ set_buffer_new(bh); set_buffer_mapped(bh); } return 0; } static int bget_one(handle_t *handle, struct buffer_head *bh) { get_bh(bh); return 0; } static int bput_one(handle_t *handle, struct buffer_head *bh) { put_bh(bh); return 0; } static int __ext4_journalled_writepage(struct page *page, unsigned int len) { struct address_space *mapping = page->mapping; struct inode *inode = mapping->host; struct buffer_head *page_bufs = NULL; handle_t *handle = NULL; int ret = 0, err = 0; int inline_data = ext4_has_inline_data(inode); struct buffer_head *inode_bh = NULL; ClearPageChecked(page); if (inline_data) { BUG_ON(page->index != 0); BUG_ON(len > ext4_get_max_inline_size(inode)); inode_bh = ext4_journalled_write_inline_data(inode, len, page); if (inode_bh == NULL) goto out; } else { page_bufs = page_buffers(page); if (!page_bufs) { BUG(); goto out; } ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL, bget_one); } /* As soon as we unlock the page, it can go away, but we have * references to buffers so we are safe */ unlock_page(page); handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, ext4_writepage_trans_blocks(inode)); if (IS_ERR(handle)) { ret = PTR_ERR(handle); goto out; } BUG_ON(!ext4_handle_valid(handle)); if (inline_data) { ret = ext4_journal_get_write_access(handle, inode_bh); err = ext4_handle_dirty_metadata(handle, inode, inode_bh); } else { ret = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL, do_journal_get_write_access); err = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL, write_end_fn); } if (ret == 0) ret = err; EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid; err = ext4_journal_stop(handle); if (!ret) ret = err; if (!ext4_has_inline_data(inode)) ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL, bput_one); ext4_set_inode_state(inode, EXT4_STATE_JDATA); out: brelse(inode_bh); return ret; } /* * Note that we don't need to start a transaction unless we're journaling data * because we should have holes filled from ext4_page_mkwrite(). We even don't * need to file the inode to the transaction's list in ordered mode because if * we are writing back data added by write(), the inode is already there and if * we are writing back data modified via mmap(), no one guarantees in which * transaction the data will hit the disk. In case we are journaling data, we * cannot start transaction directly because transaction start ranks above page * lock so we have to do some magic. * * This function can get called via... * - ext4_writepages after taking page lock (have journal handle) * - journal_submit_inode_data_buffers (no journal handle) * - shrink_page_list via the kswapd/direct reclaim (no journal handle) * - grab_page_cache when doing write_begin (have journal handle) * * We don't do any block allocation in this function. If we have page with * multiple blocks we need to write those buffer_heads that are mapped. This * is important for mmaped based write. So if we do with blocksize 1K * truncate(f, 1024); * a = mmap(f, 0, 4096); * a[0] = 'a'; * truncate(f, 4096); * we have in the page first buffer_head mapped via page_mkwrite call back * but other buffer_heads would be unmapped but dirty (dirty done via the * do_wp_page). So writepage should write the first block. If we modify * the mmap area beyond 1024 we will again get a page_fault and the * page_mkwrite callback will do the block allocation and mark the * buffer_heads mapped. * * We redirty the page if we have any buffer_heads that is either delay or * unwritten in the page. * * We can get recursively called as show below. * * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() -> * ext4_writepage() * * But since we don't do any block allocation we should not deadlock. * Page also have the dirty flag cleared so we don't get recurive page_lock. */ static int ext4_writepage(struct page *page, struct writeback_control *wbc) { int ret = 0; loff_t size; unsigned int len; struct buffer_head *page_bufs = NULL; struct inode *inode = page->mapping->host; struct ext4_io_submit io_submit; trace_ext4_writepage(page); size = i_size_read(inode); if (page->index == size >> PAGE_CACHE_SHIFT) len = size & ~PAGE_CACHE_MASK; else len = PAGE_CACHE_SIZE; page_bufs = page_buffers(page); /* * We cannot do block allocation or other extent handling in this * function. If there are buffers needing that, we have to redirty * the page. But we may reach here when we do a journal commit via * journal_submit_inode_data_buffers() and in that case we must write * allocated buffers to achieve data=ordered mode guarantees. */ if (ext4_walk_page_buffers(NULL, page_bufs, 0, len, NULL, ext4_bh_delay_or_unwritten)) { redirty_page_for_writepage(wbc, page); if (current->flags & PF_MEMALLOC) { /* * For memory cleaning there's no point in writing only * some buffers. So just bail out. Warn if we came here * from direct reclaim. */ WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) == PF_MEMALLOC); unlock_page(page); return 0; } } if (PageChecked(page) && ext4_should_journal_data(inode)) /* * It's mmapped pagecache. Add buffers and journal it. There * doesn't seem much point in redirtying the page here. */ return __ext4_journalled_writepage(page, len); ext4_io_submit_init(&io_submit, wbc); io_submit.io_end = ext4_init_io_end(inode, GFP_NOFS); if (!io_submit.io_end) { redirty_page_for_writepage(wbc, page); unlock_page(page); return -ENOMEM; } ret = ext4_bio_write_page(&io_submit, page, len, wbc); ext4_io_submit(&io_submit); /* Drop io_end reference we got from init */ ext4_put_io_end_defer(io_submit.io_end); return ret; } #define BH_FLAGS ((1 << BH_Unwritten) | (1 << BH_Delay)) /* * mballoc gives us at most this number of blocks... * XXX: That seems to be only a limitation of ext4_mb_normalize_request(). * The rest of mballoc seems to handle chunks upto full group size. */ #define MAX_WRITEPAGES_EXTENT_LEN 2048 /* * mpage_add_bh_to_extent - try to add bh to extent of blocks to map * * @mpd - extent of blocks * @lblk - logical number of the block in the file * @b_state - b_state of the buffer head added * * the function is used to collect contig. blocks in same state */ static int mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk, unsigned long b_state) { struct ext4_map_blocks *map = &mpd->map; /* Don't go larger than mballoc is willing to allocate */ if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN) return 0; /* First block in the extent? */ if (map->m_len == 0) { map->m_lblk = lblk; map->m_len = 1; map->m_flags = b_state & BH_FLAGS; return 1; } /* Can we merge the block to our big extent? */ if (lblk == map->m_lblk + map->m_len && (b_state & BH_FLAGS) == map->m_flags) { map->m_len++; return 1; } return 0; } static bool add_page_bufs_to_extent(struct mpage_da_data *mpd, struct buffer_head *head, struct buffer_head *bh, ext4_lblk_t lblk) { struct inode *inode = mpd->inode; ext4_lblk_t blocks = (i_size_read(inode) + (1 << inode->i_blkbits) - 1) >> inode->i_blkbits; do { BUG_ON(buffer_locked(bh)); if (!buffer_dirty(bh) || !buffer_mapped(bh) || (!buffer_delay(bh) && !buffer_unwritten(bh)) || lblk >= blocks) { /* Found extent to map? */ if (mpd->map.m_len) return false; if (lblk >= blocks) return true; continue; } if (!mpage_add_bh_to_extent(mpd, lblk, bh->b_state)) return false; } while (lblk++, (bh = bh->b_this_page) != head); return true; } static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page) { int len; loff_t size = i_size_read(mpd->inode); int err; BUG_ON(page->index != mpd->first_page); if (page->index == size >> PAGE_CACHE_SHIFT) len = size & ~PAGE_CACHE_MASK; else len = PAGE_CACHE_SIZE; clear_page_dirty_for_io(page); err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc); if (!err) mpd->wbc->nr_to_write--; mpd->first_page++; return err; } /* * mpage_map_buffers - update buffers corresponding to changed extent and * submit fully mapped pages for IO * * @mpd - description of extent to map, on return next extent to map * * Scan buffers corresponding to changed extent (we expect corresponding pages * to be already locked) and update buffer state according to new extent state. * We map delalloc buffers to their physical location, clear unwritten bits, * and mark buffers as uninit when we perform writes to uninitialized extents * and do extent conversion after IO is finished. If the last page is not fully * mapped, we update @map to the next extent in the last page that needs * mapping. Otherwise we submit the page for IO. */ static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd) { struct pagevec pvec; int nr_pages, i; struct inode *inode = mpd->inode; struct buffer_head *head, *bh; int bpp_bits = PAGE_CACHE_SHIFT - inode->i_blkbits; ext4_lblk_t blocks = (i_size_read(inode) + (1 << inode->i_blkbits) - 1) >> inode->i_blkbits; pgoff_t start, end; ext4_lblk_t lblk; sector_t pblock; int err; start = mpd->map.m_lblk >> bpp_bits; end = (mpd->map.m_lblk + mpd->map.m_len - 1) >> bpp_bits; lblk = start << bpp_bits; pblock = mpd->map.m_pblk; pagevec_init(&pvec, 0); while (start <= end) { nr_pages = pagevec_lookup(&pvec, inode->i_mapping, start, PAGEVEC_SIZE); if (nr_pages == 0) break; for (i = 0; i < nr_pages; i++) { struct page *page = pvec.pages[i]; if (page->index > end) break; /* Upto 'end' pages must be contiguous */ BUG_ON(page->index != start); bh = head = page_buffers(page); do { if (lblk < mpd->map.m_lblk) continue; if (lblk >= mpd->map.m_lblk + mpd->map.m_len) { /* * Buffer after end of mapped extent. * Find next buffer in the page to map. */ mpd->map.m_len = 0; mpd->map.m_flags = 0; add_page_bufs_to_extent(mpd, head, bh, lblk); pagevec_release(&pvec); return 0; } if (buffer_delay(bh)) { clear_buffer_delay(bh); bh->b_blocknr = pblock++; } clear_buffer_unwritten(bh); } while (++lblk < blocks && (bh = bh->b_this_page) != head); /* * FIXME: This is going to break if dioread_nolock * supports blocksize < pagesize as we will try to * convert potentially unmapped parts of inode. */ mpd->io_submit.io_end->size += PAGE_CACHE_SIZE; /* Page fully mapped - let IO run! */ err = mpage_submit_page(mpd, page); if (err < 0) { pagevec_release(&pvec); return err; } start++; } pagevec_release(&pvec); } /* Extent fully mapped and matches with page boundary. We are done. */ mpd->map.m_len = 0; mpd->map.m_flags = 0; return 0; } static int mpage_map_one_extent(handle_t *handle, struct mpage_da_data *mpd) { struct inode *inode = mpd->inode; struct ext4_map_blocks *map = &mpd->map; int get_blocks_flags; int err; trace_ext4_da_write_pages_extent(inode, map); /* * Call ext4_map_blocks() to allocate any delayed allocation blocks, or * to convert an uninitialized extent to be initialized (in the case * where we have written into one or more preallocated blocks). It is * possible that we're going to need more metadata blocks than * previously reserved. However we must not fail because we're in * writeback and there is nothing we can do about it so it might result * in data loss. So use reserved blocks to allocate metadata if * possible. * * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE if the blocks * in question are delalloc blocks. This affects functions in many * different parts of the allocation call path. This flag exists * primarily because we don't want to change *many* call functions, so * ext4_map_blocks() will set the EXT4_STATE_DELALLOC_RESERVED flag * once the inode's allocation semaphore is taken. */ get_blocks_flags = EXT4_GET_BLOCKS_CREATE | EXT4_GET_BLOCKS_METADATA_NOFAIL; if (ext4_should_dioread_nolock(inode)) get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT; if (map->m_flags & (1 << BH_Delay)) get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE; err = ext4_map_blocks(handle, inode, map, get_blocks_flags); if (err < 0) return err; if (map->m_flags & EXT4_MAP_UNINIT) { if (!mpd->io_submit.io_end->handle && ext4_handle_valid(handle)) { mpd->io_submit.io_end->handle = handle->h_rsv_handle; handle->h_rsv_handle = NULL; } ext4_set_io_unwritten_flag(inode, mpd->io_submit.io_end); } BUG_ON(map->m_len == 0); if (map->m_flags & EXT4_MAP_NEW) { struct block_device *bdev = inode->i_sb->s_bdev; int i; for (i = 0; i < map->m_len; i++) unmap_underlying_metadata(bdev, map->m_pblk + i); } return 0; } /* * mpage_map_and_submit_extent - map extent starting at mpd->lblk of length * mpd->len and submit pages underlying it for IO * * @handle - handle for journal operations * @mpd - extent to map * * The function maps extent starting at mpd->lblk of length mpd->len. If it is * delayed, blocks are allocated, if it is unwritten, we may need to convert * them to initialized or split the described range from larger unwritten * extent. Note that we need not map all the described range since allocation * can return less blocks or the range is covered by more unwritten extents. We * cannot map more because we are limited by reserved transaction credits. On * the other hand we always make sure that the last touched page is fully * mapped so that it can be written out (and thus forward progress is * guaranteed). After mapping we submit all mapped pages for IO. */ static int mpage_map_and_submit_extent(handle_t *handle, struct mpage_da_data *mpd, bool *give_up_on_write) { struct inode *inode = mpd->inode; struct ext4_map_blocks *map = &mpd->map; int err; loff_t disksize; mpd->io_submit.io_end->offset = ((loff_t)map->m_lblk) << inode->i_blkbits; do { err = mpage_map_one_extent(handle, mpd); if (err < 0) { struct super_block *sb = inode->i_sb; if (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED) goto invalidate_dirty_pages; /* * Let the uper layers retry transient errors. * In the case of ENOSPC, if ext4_count_free_blocks() * is non-zero, a commit should free up blocks. */ if ((err == -ENOMEM) || (err == -ENOSPC && ext4_count_free_clusters(sb))) return err; ext4_msg(sb, KERN_CRIT, "Delayed block allocation failed for " "inode %lu at logical offset %llu with" " max blocks %u with error %d", inode->i_ino, (unsigned long long)map->m_lblk, (unsigned)map->m_len, -err); ext4_msg(sb, KERN_CRIT, "This should not happen!! Data will " "be lost\n"); if (err == -ENOSPC) ext4_print_free_blocks(inode); invalidate_dirty_pages: *give_up_on_write = true; return err; } /* * Update buffer state, submit mapped pages, and get us new * extent to map */ err = mpage_map_and_submit_buffers(mpd); if (err < 0) return err; } while (map->m_len); /* Update on-disk size after IO is submitted */ disksize = ((loff_t)mpd->first_page) << PAGE_CACHE_SHIFT; if (disksize > i_size_read(inode)) disksize = i_size_read(inode); if (disksize > EXT4_I(inode)->i_disksize) { int err2; ext4_update_i_disksize(inode, disksize); err2 = ext4_mark_inode_dirty(handle, inode); if (err2) ext4_error(inode->i_sb, "Failed to mark inode %lu dirty", inode->i_ino); if (!err) err = err2; } return err; } /* * Calculate the total number of credits to reserve for one writepages * iteration. This is called from ext4_writepages(). We map an extent of * upto MAX_WRITEPAGES_EXTENT_LEN blocks and then we go on and finish mapping * the last partial page. So in total we can map MAX_WRITEPAGES_EXTENT_LEN + * bpp - 1 blocks in bpp different extents. */ static int ext4_da_writepages_trans_blocks(struct inode *inode) { int bpp = ext4_journal_blocks_per_page(inode); return ext4_meta_trans_blocks(inode, MAX_WRITEPAGES_EXTENT_LEN + bpp - 1, bpp); } /* * mpage_prepare_extent_to_map - find & lock contiguous range of dirty pages * and underlying extent to map * * @mpd - where to look for pages * * Walk dirty pages in the mapping. If they are fully mapped, submit them for * IO immediately. When we find a page which isn't mapped we start accumulating * extent of buffers underlying these pages that needs mapping (formed by * either delayed or unwritten buffers). We also lock the pages containing * these buffers. The extent found is returned in @mpd structure (starting at * mpd->lblk with length mpd->len blocks). * * Note that this function can attach bios to one io_end structure which are * neither logically nor physically contiguous. Although it may seem as an * unnecessary complication, it is actually inevitable in blocksize < pagesize * case as we need to track IO to all buffers underlying a page in one io_end. */ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd) { struct address_space *mapping = mpd->inode->i_mapping; struct pagevec pvec; unsigned int nr_pages; pgoff_t index = mpd->first_page; pgoff_t end = mpd->last_page; int tag; int i, err = 0; int blkbits = mpd->inode->i_blkbits; ext4_lblk_t lblk; struct buffer_head *head; if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages) tag = PAGECACHE_TAG_TOWRITE; else tag = PAGECACHE_TAG_DIRTY; pagevec_init(&pvec, 0); mpd->map.m_len = 0; mpd->next_page = index; while (index <= end) { nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag, min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1); if (nr_pages == 0) goto out; for (i = 0; i < nr_pages; i++) { struct page *page = pvec.pages[i]; /* * At this point, the page may be truncated or * invalidated (changing page->mapping to NULL), or * even swizzled back from swapper_space to tmpfs file * mapping. However, page->index will not change * because we have a reference on the page. */ if (page->index > end) goto out; /* If we can't merge this page, we are done. */ if (mpd->map.m_len > 0 && mpd->next_page != page->index) goto out; lock_page(page); /* * If the page is no longer dirty, or its mapping no * longer corresponds to inode we are writing (which * means it has been truncated or invalidated), or the * page is already under writeback and we are not doing * a data integrity writeback, skip the page */ if (!PageDirty(page) || (PageWriteback(page) && (mpd->wbc->sync_mode == WB_SYNC_NONE)) || unlikely(page->mapping != mapping)) { unlock_page(page); continue; } wait_on_page_writeback(page); BUG_ON(PageWriteback(page)); if (mpd->map.m_len == 0) mpd->first_page = page->index; mpd->next_page = page->index + 1; /* Add all dirty buffers to mpd */ lblk = ((ext4_lblk_t)page->index) << (PAGE_CACHE_SHIFT - blkbits); head = page_buffers(page); if (!add_page_bufs_to_extent(mpd, head, head, lblk)) goto out; /* So far everything mapped? Submit the page for IO. */ if (mpd->map.m_len == 0) { err = mpage_submit_page(mpd, page); if (err < 0) goto out; } /* * Accumulated enough dirty pages? This doesn't apply * to WB_SYNC_ALL mode. For integrity sync we have to * keep going because someone may be concurrently * dirtying pages, and we might have synced a lot of * newly appeared dirty pages, but have not synced all * of the old dirty pages. */ if (mpd->wbc->sync_mode == WB_SYNC_NONE && mpd->next_page - mpd->first_page >= mpd->wbc->nr_to_write) goto out; } pagevec_release(&pvec); cond_resched(); } return 0; out: pagevec_release(&pvec); return err; } static int __writepage(struct page *page, struct writeback_control *wbc, void *data) { struct address_space *mapping = data; int ret = ext4_writepage(page, wbc); mapping_set_error(mapping, ret); return ret; } static int ext4_writepages(struct address_space *mapping, struct writeback_control *wbc) { pgoff_t writeback_index = 0; long nr_to_write = wbc->nr_to_write; int range_whole = 0; int cycled = 1; handle_t *handle = NULL; struct mpage_da_data mpd; struct inode *inode = mapping->host; int needed_blocks, rsv_blocks = 0, ret = 0; struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb); bool done; struct blk_plug plug; bool give_up_on_write = false; trace_ext4_writepages(inode, wbc); /* * No pages to write? This is mainly a kludge to avoid starting * a transaction for special inodes like journal inode on last iput() * because that could violate lock ordering on umount */ if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) return 0; if (ext4_should_journal_data(inode)) { struct blk_plug plug; int ret; blk_start_plug(&plug); ret = write_cache_pages(mapping, wbc, __writepage, mapping); blk_finish_plug(&plug); return ret; } /* * If the filesystem has aborted, it is read-only, so return * right away instead of dumping stack traces later on that * will obscure the real source of the problem. We test * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because * the latter could be true if the filesystem is mounted * read-only, and in that case, ext4_writepages should * *never* be called, so if that ever happens, we would want * the stack trace. */ if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED)) return -EROFS; if (ext4_should_dioread_nolock(inode)) { /* * We may need to convert upto one extent per block in * the page and we may dirty the inode. */ rsv_blocks = 1 + (PAGE_CACHE_SIZE >> inode->i_blkbits); } /* * If we have inline data and arrive here, it means that * we will soon create the block for the 1st page, so * we'd better clear the inline data here. */ if (ext4_has_inline_data(inode)) { /* Just inode will be modified... */ handle = ext4_journal_start(inode, EXT4_HT_INODE, 1); if (IS_ERR(handle)) { ret = PTR_ERR(handle); goto out_writepages; } BUG_ON(ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)); ext4_destroy_inline_data(handle, inode); ext4_journal_stop(handle); } if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) range_whole = 1; if (wbc->range_cyclic) { writeback_index = mapping->writeback_index; if (writeback_index) cycled = 0; mpd.first_page = writeback_index; mpd.last_page = -1; } else { mpd.first_page = wbc->range_start >> PAGE_CACHE_SHIFT; mpd.last_page = wbc->range_end >> PAGE_CACHE_SHIFT; } mpd.inode = inode; mpd.wbc = wbc; ext4_io_submit_init(&mpd.io_submit, wbc); retry: if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) tag_pages_for_writeback(mapping, mpd.first_page, mpd.last_page); done = false; blk_start_plug(&plug); while (!done && mpd.first_page <= mpd.last_page) { /* For each extent of pages we use new io_end */ mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL); if (!mpd.io_submit.io_end) { ret = -ENOMEM; break; } /* * We have two constraints: We find one extent to map and we * must always write out whole page (makes a difference when * blocksize < pagesize) so that we don't block on IO when we * try to write out the rest of the page. Journalled mode is * not supported by delalloc. */ BUG_ON(ext4_should_journal_data(inode)); needed_blocks = ext4_da_writepages_trans_blocks(inode); /* start a new transaction */ handle = ext4_journal_start_with_reserve(inode, EXT4_HT_WRITE_PAGE, needed_blocks, rsv_blocks); if (IS_ERR(handle)) { ret = PTR_ERR(handle); ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: " "%ld pages, ino %lu; err %d", __func__, wbc->nr_to_write, inode->i_ino, ret); /* Release allocated io_end */ ext4_put_io_end(mpd.io_submit.io_end); break; } trace_ext4_da_write_pages(inode, mpd.first_page, mpd.wbc); ret = mpage_prepare_extent_to_map(&mpd); if (!ret) { if (mpd.map.m_len) ret = mpage_map_and_submit_extent(handle, &mpd, &give_up_on_write); else { /* * We scanned the whole range (or exhausted * nr_to_write), submitted what was mapped and * didn't find anything needing mapping. We are * done. */ done = true; } } ext4_journal_stop(handle); /* Submit prepared bio */ ext4_io_submit(&mpd.io_submit); /* Unlock pages we didn't use */ mpage_release_unused_pages(&mpd, give_up_on_write); /* Drop our io_end reference we got from init */ ext4_put_io_end(mpd.io_submit.io_end); if (ret == -ENOSPC && sbi->s_journal) { /* * Commit the transaction which would * free blocks released in the transaction * and try again */ jbd2_journal_force_commit_nested(sbi->s_journal); ret = 0; continue; } /* Fatal error - ENOMEM, EIO... */ if (ret) break; } blk_finish_plug(&plug); if (!ret && !cycled) { cycled = 1; mpd.last_page = writeback_index - 1; mpd.first_page = 0; goto retry; } /* Update index */ if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) /* * Set the writeback_index so that range_cyclic * mode will write it back later */ mapping->writeback_index = mpd.first_page; out_writepages: trace_ext4_writepages_result(inode, wbc, ret, nr_to_write - wbc->nr_to_write); return ret; } static int ext4_nonda_switch(struct super_block *sb) { s64 free_clusters, dirty_clusters; struct ext4_sb_info *sbi = EXT4_SB(sb); /* * switch to non delalloc mode if we are running low * on free block. The free block accounting via percpu * counters can get slightly wrong with percpu_counter_batch getting * accumulated on each CPU without updating global counters * Delalloc need an accurate free block accounting. So switch * to non delalloc when we are near to error range. */ free_clusters = percpu_counter_read_positive(&sbi->s_freeclusters_counter); dirty_clusters = percpu_counter_read_positive(&sbi->s_dirtyclusters_counter); /* * Start pushing delalloc when 1/2 of free blocks are dirty. */ if (dirty_clusters && (free_clusters < 2 * dirty_clusters)) try_to_writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE); if (2 * free_clusters < 3 * dirty_clusters || free_clusters < (dirty_clusters + EXT4_FREECLUSTERS_WATERMARK)) { /* * free block count is less than 150% of dirty blocks * or free blocks is less than watermark */ return 1; } return 0; } static int ext4_da_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata) { int ret, retries = 0; struct page *page; pgoff_t index; struct inode *inode = mapping->host; handle_t *handle; index = pos >> PAGE_CACHE_SHIFT; if (ext4_nonda_switch(inode->i_sb)) { *fsdata = (void *)FALL_BACK_TO_NONDELALLOC; return ext4_write_begin(file, mapping, pos, len, flags, pagep, fsdata); } *fsdata = (void *)0; trace_ext4_da_write_begin(inode, pos, len, flags); if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { ret = ext4_da_write_inline_data_begin(mapping, inode, pos, len, flags, pagep, fsdata); if (ret < 0) return ret; if (ret == 1) return 0; } /* * grab_cache_page_write_begin() can take a long time if the * system is thrashing due to memory pressure, or if the page * is being written back. So grab it first before we start * the transaction handle. This also allows us to allocate * the page (if needed) without using GFP_NOFS. */ retry_grab: page = grab_cache_page_write_begin(mapping, index, flags); if (!page) return -ENOMEM; unlock_page(page); /* * With delayed allocation, we don't log the i_disksize update * if there is delayed block allocation. But we still need * to journalling the i_disksize update if writes to the end * of file which has an already mapped buffer. */ retry_journal: handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, 1); if (IS_ERR(handle)) { page_cache_release(page); return PTR_ERR(handle); } lock_page(page); if (page->mapping != mapping) { /* The page got truncated from under us */ unlock_page(page); page_cache_release(page); ext4_journal_stop(handle); goto retry_grab; } /* In case writeback began while the page was unlocked */ wait_on_page_writeback(page); ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep); if (ret < 0) { unlock_page(page); ext4_journal_stop(handle); /* * block_write_begin may have instantiated a few blocks * outside i_size. Trim these off again. Don't need * i_size_read because we hold i_mutex. */ if (pos + len > inode->i_size) ext4_truncate_failed_write(inode); if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) goto retry_journal; page_cache_release(page); return ret; } *pagep = page; return ret; } /* * Check if we should update i_disksize * when write to the end of file but not require block allocation */ static int ext4_da_should_update_i_disksize(struct page *page, unsigned long offset) { struct buffer_head *bh; struct inode *inode = page->mapping->host; unsigned int idx; int i; bh = page_buffers(page); idx = offset >> inode->i_blkbits; for (i = 0; i < idx; i++) bh = bh->b_this_page; if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh)) return 0; return 1; } static int ext4_da_write_end(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned copied, struct page *page, void *fsdata) { struct inode *inode = mapping->host; int ret = 0, ret2; handle_t *handle = ext4_journal_current_handle(); loff_t new_i_size; unsigned long start, end; int write_mode = (int)(unsigned long)fsdata; if (write_mode == FALL_BACK_TO_NONDELALLOC) return ext4_write_end(file, mapping, pos, len, copied, page, fsdata); trace_ext4_da_write_end(inode, pos, len, copied); start = pos & (PAGE_CACHE_SIZE - 1); end = start + copied - 1; /* * generic_write_end() will run mark_inode_dirty() if i_size * changes. So let's piggyback the i_disksize mark_inode_dirty * into that. */ new_i_size = pos + copied; if (copied && new_i_size > EXT4_I(inode)->i_disksize) { if (ext4_has_inline_data(inode) || ext4_da_should_update_i_disksize(page, end)) { down_write(&EXT4_I(inode)->i_data_sem); if (new_i_size > EXT4_I(inode)->i_disksize) EXT4_I(inode)->i_disksize = new_i_size; up_write(&EXT4_I(inode)->i_data_sem); /* We need to mark inode dirty even if * new_i_size is less that inode->i_size * bu greater than i_disksize.(hint delalloc) */ ext4_mark_inode_dirty(handle, inode); } } if (write_mode != CONVERT_INLINE_DATA && ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) && ext4_has_inline_data(inode)) ret2 = ext4_da_write_inline_data_end(inode, pos, len, copied, page); else ret2 = generic_write_end(file, mapping, pos, len, copied, page, fsdata); copied = ret2; if (ret2 < 0) ret = ret2; ret2 = ext4_journal_stop(handle); if (!ret) ret = ret2; return ret ? ret : copied; } static void ext4_da_invalidatepage(struct page *page, unsigned int offset, unsigned int length) { /* * Drop reserved blocks */ BUG_ON(!PageLocked(page)); if (!page_has_buffers(page)) goto out; ext4_da_page_release_reservation(page, offset, length); out: ext4_invalidatepage(page, offset, length); return; } /* * Force all delayed allocation blocks to be allocated for a given inode. */ int ext4_alloc_da_blocks(struct inode *inode) { trace_ext4_alloc_da_blocks(inode); if (!EXT4_I(inode)->i_reserved_data_blocks && !EXT4_I(inode)->i_reserved_meta_blocks) return 0; /* * We do something simple for now. The filemap_flush() will * also start triggering a write of the data blocks, which is * not strictly speaking necessary (and for users of * laptop_mode, not even desirable). However, to do otherwise * would require replicating code paths in: * * ext4_writepages() -> * write_cache_pages() ---> (via passed in callback function) * __mpage_da_writepage() --> * mpage_add_bh_to_extent() * mpage_da_map_blocks() * * The problem is that write_cache_pages(), located in * mm/page-writeback.c, marks pages clean in preparation for * doing I/O, which is not desirable if we're not planning on * doing I/O at all. * * We could call write_cache_pages(), and then redirty all of * the pages by calling redirty_page_for_writepage() but that * would be ugly in the extreme. So instead we would need to * replicate parts of the code in the above functions, * simplifying them because we wouldn't actually intend to * write out the pages, but rather only collect contiguous * logical block extents, call the multi-block allocator, and * then update the buffer heads with the block allocations. * * For now, though, we'll cheat by calling filemap_flush(), * which will map the blocks, and start the I/O, but not * actually wait for the I/O to complete. */ return filemap_flush(inode->i_mapping); } /* * bmap() is special. It gets used by applications such as lilo and by * the swapper to find the on-disk block of a specific piece of data. * * Naturally, this is dangerous if the block concerned is still in the * journal. If somebody makes a swapfile on an ext4 data-journaling * filesystem and enables swap, then they may get a nasty shock when the * data getting swapped to that swapfile suddenly gets overwritten by * the original zero's written out previously to the journal and * awaiting writeback in the kernel's buffer cache. * * So, if we see any bmap calls here on a modified, data-journaled file, * take extra steps to flush any blocks which might be in the cache. */ static sector_t ext4_bmap(struct address_space *mapping, sector_t block) { struct inode *inode = mapping->host; journal_t *journal; int err; /* * We can get here for an inline file via the FIBMAP ioctl */ if (ext4_has_inline_data(inode)) return 0; if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) && test_opt(inode->i_sb, DELALLOC)) { /* * With delalloc we want to sync the file * so that we can make sure we allocate * blocks for file */ filemap_write_and_wait(mapping); } if (EXT4_JOURNAL(inode) && ext4_test_inode_state(inode, EXT4_STATE_JDATA)) { /* * This is a REALLY heavyweight approach, but the use of * bmap on dirty files is expected to be extremely rare: * only if we run lilo or swapon on a freshly made file * do we expect this to happen. * * (bmap requires CAP_SYS_RAWIO so this does not * represent an unprivileged user DOS attack --- we'd be * in trouble if mortal users could trigger this path at * will.) * * NB. EXT4_STATE_JDATA is not set on files other than * regular files. If somebody wants to bmap a directory * or symlink and gets confused because the buffer * hasn't yet been flushed to disk, they deserve * everything they get. */ ext4_clear_inode_state(inode, EXT4_STATE_JDATA); journal = EXT4_JOURNAL(inode); jbd2_journal_lock_updates(journal); err = jbd2_journal_flush(journal); jbd2_journal_unlock_updates(journal); if (err) return 0; } return generic_block_bmap(mapping, block, ext4_get_block); } static int ext4_readpage(struct file *file, struct page *page) { int ret = -EAGAIN; struct inode *inode = page->mapping->host; trace_ext4_readpage(page); if (ext4_has_inline_data(inode)) ret = ext4_readpage_inline(inode, page); if (ret == -EAGAIN) return mpage_readpage(page, ext4_get_block); return ret; } static int ext4_readpages(struct file *file, struct address_space *mapping, struct list_head *pages, unsigned nr_pages) { struct inode *inode = mapping->host; /* If the file has inline data, no need to do readpages. */ if (ext4_has_inline_data(inode)) return 0; return mpage_readpages(mapping, pages, nr_pages, ext4_get_block); } static void ext4_invalidatepage(struct page *page, unsigned int offset, unsigned int length) { trace_ext4_invalidatepage(page, offset, length); /* No journalling happens on data buffers when this function is used */ WARN_ON(page_has_buffers(page) && buffer_jbd(page_buffers(page))); block_invalidatepage(page, offset, length); } static int __ext4_journalled_invalidatepage(struct page *page, unsigned int offset, unsigned int length) { journal_t *journal = EXT4_JOURNAL(page->mapping->host); trace_ext4_journalled_invalidatepage(page, offset, length); /* * If it's a full truncate we just forget about the pending dirtying */ if (offset == 0 && length == PAGE_CACHE_SIZE) ClearPageChecked(page); return jbd2_journal_invalidatepage(journal, page, offset, length); } /* Wrapper for aops... */ static void ext4_journalled_invalidatepage(struct page *page, unsigned int offset, unsigned int length) { WARN_ON(__ext4_journalled_invalidatepage(page, offset, length) < 0); } static int ext4_releasepage(struct page *page, gfp_t wait) { journal_t *journal = EXT4_JOURNAL(page->mapping->host); trace_ext4_releasepage(page); /* Page has dirty journalled data -> cannot release */ if (PageChecked(page)) return 0; if (journal) return jbd2_journal_try_to_free_buffers(journal, page, wait); else return try_to_free_buffers(page); } /* * ext4_get_block used when preparing for a DIO write or buffer write. * We allocate an uinitialized extent if blocks haven't been allocated. * The extent will be converted to initialized after the IO is complete. */ int ext4_get_block_write(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n", inode->i_ino, create); return _ext4_get_block(inode, iblock, bh_result, EXT4_GET_BLOCKS_IO_CREATE_EXT); } static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { ext4_debug("ext4_get_block_write_nolock: inode %lu, create flag %d\n", inode->i_ino, create); return _ext4_get_block(inode, iblock, bh_result, EXT4_GET_BLOCKS_NO_LOCK); } static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset, ssize_t size, void *private) { ext4_io_end_t *io_end = iocb->private; /* if not async direct IO just return */ if (!io_end) return; ext_debug("ext4_end_io_dio(): io_end 0x%p " "for inode %lu, iocb 0x%p, offset %llu, size %zd\n", iocb->private, io_end->inode->i_ino, iocb, offset, size); iocb->private = NULL; io_end->offset = offset; io_end->size = size; ext4_put_io_end(io_end); } /* * For ext4 extent files, ext4 will do direct-io write to holes, * preallocated extents, and those write extend the file, no need to * fall back to buffered IO. * * For holes, we fallocate those blocks, mark them as uninitialized * If those blocks were preallocated, we mark sure they are split, but * still keep the range to write as uninitialized. * * The unwritten extents will be converted to written when DIO is completed. * For async direct IO, since the IO may still pending when return, we * set up an end_io call back function, which will do the conversion * when async direct IO completed. * * If the O_DIRECT write will extend the file then add this inode to the * orphan list. So recovery will truncate it back to the original size * if the machine crashes during the write. * */ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t offset, unsigned long nr_segs) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; ssize_t ret; size_t count = iov_length(iov, nr_segs); int overwrite = 0; get_block_t *get_block_func = NULL; int dio_flags = 0; loff_t final_size = offset + count; ext4_io_end_t *io_end = NULL; /* Use the old path for reads and writes beyond i_size. */ if (rw != WRITE || final_size > inode->i_size) return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs); BUG_ON(iocb->private == NULL); /* * Make all waiters for direct IO properly wait also for extent * conversion. This also disallows race between truncate() and * overwrite DIO as i_dio_count needs to be incremented under i_mutex. */ if (rw == WRITE) atomic_inc(&inode->i_dio_count); /* If we do a overwrite dio, i_mutex locking can be released */ overwrite = *((int *)iocb->private); if (overwrite) { down_read(&EXT4_I(inode)->i_data_sem); mutex_unlock(&inode->i_mutex); } /* * We could direct write to holes and fallocate. * * Allocated blocks to fill the hole are marked as * uninitialized to prevent parallel buffered read to expose * the stale data before DIO complete the data IO. * * As to previously fallocated extents, ext4 get_block will * just simply mark the buffer mapped but still keep the * extents uninitialized. * * For non AIO case, we will convert those unwritten extents * to written after return back from blockdev_direct_IO. * * For async DIO, the conversion needs to be deferred when the * IO is completed. The ext4 end_io callback function will be * called to take care of the conversion work. Here for async * case, we allocate an io_end structure to hook to the iocb. */ iocb->private = NULL; ext4_inode_aio_set(inode, NULL); if (!is_sync_kiocb(iocb)) { io_end = ext4_init_io_end(inode, GFP_NOFS); if (!io_end) { ret = -ENOMEM; goto retake_lock; } /* * Grab reference for DIO. Will be dropped in ext4_end_io_dio() */ iocb->private = ext4_get_io_end(io_end); /* * we save the io structure for current async direct * IO, so that later ext4_map_blocks() could flag the * io structure whether there is a unwritten extents * needs to be converted when IO is completed. */ ext4_inode_aio_set(inode, io_end); } if (overwrite) { get_block_func = ext4_get_block_write_nolock; } else { get_block_func = ext4_get_block_write; dio_flags = DIO_LOCKING; } ret = __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, offset, nr_segs, get_block_func, ext4_end_io_dio, NULL, dio_flags); /* * Put our reference to io_end. This can free the io_end structure e.g. * in sync IO case or in case of error. It can even perform extent * conversion if all bios we submitted finished before we got here. * Note that in that case iocb->private can be already set to NULL * here. */ if (io_end) { ext4_inode_aio_set(inode, NULL); ext4_put_io_end(io_end); /* * When no IO was submitted ext4_end_io_dio() was not * called so we have to put iocb's reference. */ if (ret <= 0 && ret != -EIOCBQUEUED && iocb->private) { WARN_ON(iocb->private != io_end); WARN_ON(io_end->flag & EXT4_IO_END_UNWRITTEN); ext4_put_io_end(io_end); iocb->private = NULL; } } if (ret > 0 && !overwrite && ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN)) { int err; /* * for non AIO case, since the IO is already * completed, we could do the conversion right here */ err = ext4_convert_unwritten_extents(NULL, inode, offset, ret); if (err < 0) ret = err; ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); } retake_lock: if (rw == WRITE) inode_dio_done(inode); /* take i_mutex locking again if we do a ovewrite dio */ if (overwrite) { up_read(&EXT4_I(inode)->i_data_sem); mutex_lock(&inode->i_mutex); } return ret; } static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t offset, unsigned long nr_segs) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; ssize_t ret; /* * If we are doing data journalling we don't support O_DIRECT */ if (ext4_should_journal_data(inode)) return 0; /* Let buffer I/O handle the inline data case. */ if (ext4_has_inline_data(inode)) return 0; trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw); if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs); else ret = ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs); trace_ext4_direct_IO_exit(inode, offset, iov_length(iov, nr_segs), rw, ret); return ret; } /* * Pages can be marked dirty completely asynchronously from ext4's journalling * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do * much here because ->set_page_dirty is called under VFS locks. The page is * not necessarily locked. * * We cannot just dirty the page and leave attached buffers clean, because the * buffers' dirty state is "definitive". We cannot just set the buffers dirty * or jbddirty because all the journalling code will explode. * * So what we do is to mark the page "pending dirty" and next time writepage * is called, propagate that into the buffers appropriately. */ static int ext4_journalled_set_page_dirty(struct page *page) { SetPageChecked(page); return __set_page_dirty_nobuffers(page); } static const struct address_space_operations ext4_aops = { .readpage = ext4_readpage, .readpages = ext4_readpages, .writepage = ext4_writepage, .writepages = ext4_writepages, .write_begin = ext4_write_begin, .write_end = ext4_write_end, .bmap = ext4_bmap, .invalidatepage = ext4_invalidatepage, .releasepage = ext4_releasepage, .direct_IO = ext4_direct_IO, .migratepage = buffer_migrate_page, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, }; static const struct address_space_operations ext4_journalled_aops = { .readpage = ext4_readpage, .readpages = ext4_readpages, .writepage = ext4_writepage, .writepages = ext4_writepages, .write_begin = ext4_write_begin, .write_end = ext4_journalled_write_end, .set_page_dirty = ext4_journalled_set_page_dirty, .bmap = ext4_bmap, .invalidatepage = ext4_journalled_invalidatepage, .releasepage = ext4_releasepage, .direct_IO = ext4_direct_IO, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, }; static const struct address_space_operations ext4_da_aops = { .readpage = ext4_readpage, .readpages = ext4_readpages, .writepage = ext4_writepage, .writepages = ext4_writepages, .write_begin = ext4_da_write_begin, .write_end = ext4_da_write_end, .bmap = ext4_bmap, .invalidatepage = ext4_da_invalidatepage, .releasepage = ext4_releasepage, .direct_IO = ext4_direct_IO, .migratepage = buffer_migrate_page, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, }; void ext4_set_aops(struct inode *inode) { switch (ext4_inode_journal_mode(inode)) { case EXT4_INODE_ORDERED_DATA_MODE: ext4_set_inode_state(inode, EXT4_STATE_ORDERED_MODE); break; case EXT4_INODE_WRITEBACK_DATA_MODE: ext4_clear_inode_state(inode, EXT4_STATE_ORDERED_MODE); break; case EXT4_INODE_JOURNAL_DATA_MODE: inode->i_mapping->a_ops = &ext4_journalled_aops; return; default: BUG(); } if (test_opt(inode->i_sb, DELALLOC)) inode->i_mapping->a_ops = &ext4_da_aops; else inode->i_mapping->a_ops = &ext4_aops; } /* * ext4_block_truncate_page() zeroes out a mapping from file offset `from' * up to the end of the block which corresponds to `from'. * This required during truncate. We need to physically zero the tail end * of that block so it doesn't yield old data if the file is later grown. */ int ext4_block_truncate_page(handle_t *handle, struct address_space *mapping, loff_t from) { unsigned offset = from & (PAGE_CACHE_SIZE-1); unsigned length; unsigned blocksize; struct inode *inode = mapping->host; blocksize = inode->i_sb->s_blocksize; length = blocksize - (offset & (blocksize - 1)); return ext4_block_zero_page_range(handle, mapping, from, length); } /* * ext4_block_zero_page_range() zeros out a mapping of length 'length' * starting from file offset 'from'. The range to be zero'd must * be contained with in one block. If the specified range exceeds * the end of the block it will be shortened to end of the block * that cooresponds to 'from' */ int ext4_block_zero_page_range(handle_t *handle, struct address_space *mapping, loff_t from, loff_t length) { ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT; unsigned offset = from & (PAGE_CACHE_SIZE-1); unsigned blocksize, max, pos; ext4_lblk_t iblock; struct inode *inode = mapping->host; struct buffer_head *bh; struct page *page; int err = 0; page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT, mapping_gfp_mask(mapping) & ~__GFP_FS); if (!page) return -ENOMEM; blocksize = inode->i_sb->s_blocksize; max = blocksize - (offset & (blocksize - 1)); /* * correct length if it does not fall between * 'from' and the end of the block */ if (length > max || length < 0) length = max; iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); if (!page_has_buffers(page)) create_empty_buffers(page, blocksize, 0); /* Find the buffer that contains "offset" */ bh = page_buffers(page); pos = blocksize; while (offset >= pos) { bh = bh->b_this_page; iblock++; pos += blocksize; } if (buffer_freed(bh)) { BUFFER_TRACE(bh, "freed: skip"); goto unlock; } if (!buffer_mapped(bh)) { BUFFER_TRACE(bh, "unmapped"); ext4_get_block(inode, iblock, bh, 0); /* unmapped? It's a hole - nothing to do */ if (!buffer_mapped(bh)) { BUFFER_TRACE(bh, "still unmapped"); goto unlock; } } /* Ok, it's mapped. Make sure it's up-to-date */ if (PageUptodate(page)) set_buffer_uptodate(bh); if (!buffer_uptodate(bh)) { err = -EIO; ll_rw_block(READ, 1, &bh); wait_on_buffer(bh); /* Uhhuh. Read error. Complain and punt. */ if (!buffer_uptodate(bh)) goto unlock; } if (ext4_should_journal_data(inode)) { BUFFER_TRACE(bh, "get write access"); err = ext4_journal_get_write_access(handle, bh); if (err) goto unlock; } zero_user(page, offset, length); BUFFER_TRACE(bh, "zeroed end of block"); if (ext4_should_journal_data(inode)) { err = ext4_handle_dirty_metadata(handle, inode, bh); } else { err = 0; mark_buffer_dirty(bh); if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE)) err = ext4_jbd2_file_inode(handle, inode); } unlock: unlock_page(page); page_cache_release(page); return err; } int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode, loff_t lstart, loff_t length) { struct super_block *sb = inode->i_sb; struct address_space *mapping = inode->i_mapping; unsigned partial_start, partial_end; ext4_fsblk_t start, end; loff_t byte_end = (lstart + length - 1); int err = 0; partial_start = lstart & (sb->s_blocksize - 1); partial_end = byte_end & (sb->s_blocksize - 1); start = lstart >> sb->s_blocksize_bits; end = byte_end >> sb->s_blocksize_bits; /* Handle partial zero within the single block */ if (start == end && (partial_start || (partial_end != sb->s_blocksize - 1))) { err = ext4_block_zero_page_range(handle, mapping, lstart, length); return err; } /* Handle partial zero out on the start of the range */ if (partial_start) { err = ext4_block_zero_page_range(handle, mapping, lstart, sb->s_blocksize); if (err) return err; } /* Handle partial zero out on the end of the range */ if (partial_end != sb->s_blocksize - 1) err = ext4_block_zero_page_range(handle, mapping, byte_end - partial_end, partial_end + 1); return err; } int ext4_can_truncate(struct inode *inode) { if (S_ISREG(inode->i_mode)) return 1; if (S_ISDIR(inode->i_mode)) return 1; if (S_ISLNK(inode->i_mode)) return !ext4_inode_is_fast_symlink(inode); return 0; } /* * ext4_punch_hole: punches a hole in a file by releaseing the blocks * associated with the given offset and length * * @inode: File inode * @offset: The offset where the hole will begin * @len: The length of the hole * * Returns: 0 on success or negative on failure */ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length) { struct super_block *sb = inode->i_sb; ext4_lblk_t first_block, stop_block; struct address_space *mapping = inode->i_mapping; loff_t first_block_offset, last_block_offset; handle_t *handle; unsigned int credits; int ret = 0; if (!S_ISREG(inode->i_mode)) return -EOPNOTSUPP; if (EXT4_SB(sb)->s_cluster_ratio > 1) { /* TODO: Add support for bigalloc file systems */ return -EOPNOTSUPP; } trace_ext4_punch_hole(inode, offset, length); /* * Write out all dirty pages to avoid race conditions * Then release them. */ if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { ret = filemap_write_and_wait_range(mapping, offset, offset + length - 1); if (ret) return ret; } mutex_lock(&inode->i_mutex); /* It's not possible punch hole on append only file */ if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) { ret = -EPERM; goto out_mutex; } if (IS_SWAPFILE(inode)) { ret = -ETXTBSY; goto out_mutex; } /* No need to punch hole beyond i_size */ if (offset >= inode->i_size) goto out_mutex; /* * If the hole extends beyond i_size, set the hole * to end after the page that contains i_size */ if (offset + length > inode->i_size) { length = inode->i_size + PAGE_CACHE_SIZE - (inode->i_size & (PAGE_CACHE_SIZE - 1)) - offset; } if (offset & (sb->s_blocksize - 1) || (offset + length) & (sb->s_blocksize - 1)) { /* * Attach jinode to inode for jbd2 if we do any zeroing of * partial block */ ret = ext4_inode_attach_jinode(inode); if (ret < 0) goto out_mutex; } first_block_offset = round_up(offset, sb->s_blocksize); last_block_offset = round_down((offset + length), sb->s_blocksize) - 1; /* Now release the pages and zero block aligned part of pages*/ if (last_block_offset > first_block_offset) truncate_pagecache_range(inode, first_block_offset, last_block_offset); /* Wait all existing dio workers, newcomers will block on i_mutex */ ext4_inode_block_unlocked_dio(inode); inode_dio_wait(inode); if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) credits = ext4_writepage_trans_blocks(inode); else credits = ext4_blocks_for_truncate(inode); handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); if (IS_ERR(handle)) { ret = PTR_ERR(handle); ext4_std_error(sb, ret); goto out_dio; } ret = ext4_zero_partial_blocks(handle, inode, offset, length); if (ret) goto out_stop; first_block = (offset + sb->s_blocksize - 1) >> EXT4_BLOCK_SIZE_BITS(sb); stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb); /* If there are no blocks to remove, return now */ if (first_block >= stop_block) goto out_stop; down_write(&EXT4_I(inode)->i_data_sem); ext4_discard_preallocations(inode); ret = ext4_es_remove_extent(inode, first_block, stop_block - first_block); if (ret) { up_write(&EXT4_I(inode)->i_data_sem); goto out_stop; } if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) ret = ext4_ext_remove_space(inode, first_block, stop_block - 1); else ret = ext4_free_hole_blocks(handle, inode, first_block, stop_block); ext4_discard_preallocations(inode); up_write(&EXT4_I(inode)->i_data_sem); if (IS_SYNC(inode)) ext4_handle_sync(handle); inode->i_mtime = inode->i_ctime = ext4_current_time(inode); ext4_mark_inode_dirty(handle, inode); out_stop: ext4_journal_stop(handle); out_dio: ext4_inode_resume_unlocked_dio(inode); out_mutex: mutex_unlock(&inode->i_mutex); return ret; } int ext4_inode_attach_jinode(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); struct jbd2_inode *jinode; if (ei->jinode || !EXT4_SB(inode->i_sb)->s_journal) return 0; jinode = jbd2_alloc_inode(GFP_KERNEL); spin_lock(&inode->i_lock); if (!ei->jinode) { if (!jinode) { spin_unlock(&inode->i_lock); return -ENOMEM; } ei->jinode = jinode; jbd2_journal_init_jbd_inode(ei->jinode, inode); jinode = NULL; } spin_unlock(&inode->i_lock); if (unlikely(jinode != NULL)) jbd2_free_inode(jinode); return 0; } /* * ext4_truncate() * * We block out ext4_get_block() block instantiations across the entire * transaction, and VFS/VM ensures that ext4_truncate() cannot run * simultaneously on behalf of the same inode. * * As we work through the truncate and commit bits of it to the journal there * is one core, guiding principle: the file's tree must always be consistent on * disk. We must be able to restart the truncate after a crash. * * The file's tree may be transiently inconsistent in memory (although it * probably isn't), but whenever we close off and commit a journal transaction, * the contents of (the filesystem + the journal) must be consistent and * restartable. It's pretty simple, really: bottom up, right to left (although * left-to-right works OK too). * * Note that at recovery time, journal replay occurs *before* the restart of * truncate against the orphan inode list. * * The committed inode has the new, desired i_size (which is the same as * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see * that this inode's truncate did not complete and it will again call * ext4_truncate() to have another go. So there will be instantiated blocks * to the right of the truncation point in a crashed ext4 filesystem. But * that's fine - as long as they are linked from the inode, the post-crash * ext4_truncate() run will find them and release them. */ void ext4_truncate(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); unsigned int credits; handle_t *handle; struct address_space *mapping = inode->i_mapping; /* * There is a possibility that we're either freeing the inode * or it completely new indode. In those cases we might not * have i_mutex locked because it's not necessary. */ if (!(inode->i_state & (I_NEW|I_FREEING))) WARN_ON(!mutex_is_locked(&inode->i_mutex)); trace_ext4_truncate_enter(inode); if (!ext4_can_truncate(inode)) return; ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS); if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC)) ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE); if (ext4_has_inline_data(inode)) { int has_inline = 1; ext4_inline_data_truncate(inode, &has_inline); if (has_inline) return; } /* If we zero-out tail of the page, we have to create jinode for jbd2 */ if (inode->i_size & (inode->i_sb->s_blocksize - 1)) { if (ext4_inode_attach_jinode(inode) < 0) return; } if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) credits = ext4_writepage_trans_blocks(inode); else credits = ext4_blocks_for_truncate(inode); handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); if (IS_ERR(handle)) { ext4_std_error(inode->i_sb, PTR_ERR(handle)); return; } if (inode->i_size & (inode->i_sb->s_blocksize - 1)) ext4_block_truncate_page(handle, mapping, inode->i_size); /* * We add the inode to the orphan list, so that if this * truncate spans multiple transactions, and we crash, we will * resume the truncate when the filesystem recovers. It also * marks the inode dirty, to catch the new size. * * Implication: the file must always be in a sane, consistent * truncatable state while each transaction commits. */ if (ext4_orphan_add(handle, inode)) goto out_stop; down_write(&EXT4_I(inode)->i_data_sem); ext4_discard_preallocations(inode); if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) ext4_ext_truncate(handle, inode); else ext4_ind_truncate(handle, inode); up_write(&ei->i_data_sem); if (IS_SYNC(inode)) ext4_handle_sync(handle); out_stop: /* * If this was a simple ftruncate() and the file will remain alive, * then we need to clear up the orphan record which we created above. * However, if this was a real unlink then we were called by * ext4_delete_inode(), and we allow that function to clean up the * orphan info for us. */ if (inode->i_nlink) ext4_orphan_del(handle, inode); inode->i_mtime = inode->i_ctime = ext4_current_time(inode); ext4_mark_inode_dirty(handle, inode); ext4_journal_stop(handle); trace_ext4_truncate_exit(inode); } /* * ext4_get_inode_loc returns with an extra refcount against the inode's * underlying buffer_head on success. If 'in_mem' is true, we have all * data in memory that is needed to recreate the on-disk version of this * inode. */ static int __ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc, int in_mem) { struct ext4_group_desc *gdp; struct buffer_head *bh; struct super_block *sb = inode->i_sb; ext4_fsblk_t block; int inodes_per_block, inode_offset; iloc->bh = NULL; if (!ext4_valid_inum(sb, inode->i_ino)) return -EIO; iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb); gdp = ext4_get_group_desc(sb, iloc->block_group, NULL); if (!gdp) return -EIO; /* * Figure out the offset within the block group inode table */ inodes_per_block = EXT4_SB(sb)->s_inodes_per_block; inode_offset = ((inode->i_ino - 1) % EXT4_INODES_PER_GROUP(sb)); block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block); iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb); bh = sb_getblk(sb, block); if (unlikely(!bh)) return -ENOMEM; if (!buffer_uptodate(bh)) { lock_buffer(bh); /* * If the buffer has the write error flag, we have failed * to write out another inode in the same block. In this * case, we don't have to read the block because we may * read the old inode data successfully. */ if (buffer_write_io_error(bh) && !buffer_uptodate(bh)) set_buffer_uptodate(bh); if (buffer_uptodate(bh)) { /* someone brought it uptodate while we waited */ unlock_buffer(bh); goto has_buffer; } /* * If we have all information of the inode in memory and this * is the only valid inode in the block, we need not read the * block. */ if (in_mem) { struct buffer_head *bitmap_bh; int i, start; start = inode_offset & ~(inodes_per_block - 1); /* Is the inode bitmap in cache? */ bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp)); if (unlikely(!bitmap_bh)) goto make_io; /* * If the inode bitmap isn't in cache then the * optimisation may end up performing two reads instead * of one, so skip it. */ if (!buffer_uptodate(bitmap_bh)) { brelse(bitmap_bh); goto make_io; } for (i = start; i < start + inodes_per_block; i++) { if (i == inode_offset) continue; if (ext4_test_bit(i, bitmap_bh->b_data)) break; } brelse(bitmap_bh); if (i == start + inodes_per_block) { /* all other inodes are free, so skip I/O */ memset(bh->b_data, 0, bh->b_size); set_buffer_uptodate(bh); unlock_buffer(bh); goto has_buffer; } } make_io: /* * If we need to do any I/O, try to pre-readahead extra * blocks from the inode table. */ if (EXT4_SB(sb)->s_inode_readahead_blks) { ext4_fsblk_t b, end, table; unsigned num; __u32 ra_blks = EXT4_SB(sb)->s_inode_readahead_blks; table = ext4_inode_table(sb, gdp); /* s_inode_readahead_blks is always a power of 2 */ b = block & ~((ext4_fsblk_t) ra_blks - 1); if (table > b) b = table; end = b + ra_blks; num = EXT4_INODES_PER_GROUP(sb); if (ext4_has_group_desc_csum(sb)) num -= ext4_itable_unused_count(sb, gdp); table += num / inodes_per_block; if (end > table) end = table; while (b <= end) sb_breadahead(sb, b++); } /* * There are other valid inodes in the buffer, this inode * has in-inode xattrs, or we don't have this inode in memory. * Read the block from disk. */ trace_ext4_load_inode(inode); get_bh(bh); bh->b_end_io = end_buffer_read_sync; submit_bh(READ | REQ_META | REQ_PRIO, bh); wait_on_buffer(bh); if (!buffer_uptodate(bh)) { EXT4_ERROR_INODE_BLOCK(inode, block, "unable to read itable block"); brelse(bh); return -EIO; } } has_buffer: iloc->bh = bh; return 0; } int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) { /* We have all inode data except xattrs in memory here. */ return __ext4_get_inode_loc(inode, iloc, !ext4_test_inode_state(inode, EXT4_STATE_XATTR)); } void ext4_set_inode_flags(struct inode *inode) { unsigned int flags = EXT4_I(inode)->i_flags; inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); if (flags & EXT4_SYNC_FL) inode->i_flags |= S_SYNC; if (flags & EXT4_APPEND_FL) inode->i_flags |= S_APPEND; if (flags & EXT4_IMMUTABLE_FL) inode->i_flags |= S_IMMUTABLE; if (flags & EXT4_NOATIME_FL) inode->i_flags |= S_NOATIME; if (flags & EXT4_DIRSYNC_FL) inode->i_flags |= S_DIRSYNC; } /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */ void ext4_get_inode_flags(struct ext4_inode_info *ei) { unsigned int vfs_fl; unsigned long old_fl, new_fl; do { vfs_fl = ei->vfs_inode.i_flags; old_fl = ei->i_flags; new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL| EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL| EXT4_DIRSYNC_FL); if (vfs_fl & S_SYNC) new_fl |= EXT4_SYNC_FL; if (vfs_fl & S_APPEND) new_fl |= EXT4_APPEND_FL; if (vfs_fl & S_IMMUTABLE) new_fl |= EXT4_IMMUTABLE_FL; if (vfs_fl & S_NOATIME) new_fl |= EXT4_NOATIME_FL; if (vfs_fl & S_DIRSYNC) new_fl |= EXT4_DIRSYNC_FL; } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl); } static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode, struct ext4_inode_info *ei) { blkcnt_t i_blocks ; struct inode *inode = &(ei->vfs_inode); struct super_block *sb = inode->i_sb; if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) { /* we are using combined 48 bit field */ i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 | le32_to_cpu(raw_inode->i_blocks_lo); if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) { /* i_blocks represent file system block size */ return i_blocks << (inode->i_blkbits - 9); } else { return i_blocks; } } else { return le32_to_cpu(raw_inode->i_blocks_lo); } } static inline void ext4_iget_extra_inode(struct inode *inode, struct ext4_inode *raw_inode, struct ext4_inode_info *ei) { __le32 *magic = (void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize; if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC)) { ext4_set_inode_state(inode, EXT4_STATE_XATTR); ext4_find_inline_data_nolock(inode); } else EXT4_I(inode)->i_inline_off = 0; } struct inode *ext4_iget(struct super_block *sb, unsigned long ino) { struct ext4_iloc iloc; struct ext4_inode *raw_inode; struct ext4_inode_info *ei; struct inode *inode; journal_t *journal = EXT4_SB(sb)->s_journal; long ret; int block; uid_t i_uid; gid_t i_gid; inode = iget_locked(sb, ino); if (!inode) return ERR_PTR(-ENOMEM); if (!(inode->i_state & I_NEW)) return inode; ei = EXT4_I(inode); iloc.bh = NULL; ret = __ext4_get_inode_loc(inode, &iloc, 0); if (ret < 0) goto bad_inode; raw_inode = ext4_raw_inode(&iloc); if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize); if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > EXT4_INODE_SIZE(inode->i_sb)) { EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)", EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize, EXT4_INODE_SIZE(inode->i_sb)); ret = -EIO; goto bad_inode; } } else ei->i_extra_isize = 0; /* Precompute checksum seed for inode metadata */ if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); __u32 csum; __le32 inum = cpu_to_le32(inode->i_ino); __le32 gen = raw_inode->i_generation; csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum, sizeof(inum)); ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen, sizeof(gen)); } if (!ext4_inode_csum_verify(inode, raw_inode, ei)) { EXT4_ERROR_INODE(inode, "checksum invalid"); ret = -EIO; goto bad_inode; } inode->i_mode = le16_to_cpu(raw_inode->i_mode); i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); if (!(test_opt(inode->i_sb, NO_UID32))) { i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; } i_uid_write(inode, i_uid); i_gid_write(inode, i_gid); set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */ ei->i_inline_off = 0; ei->i_dir_start_lookup = 0; ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); /* We now have enough fields to check if the inode was active or not. * This is needed because nfsd might try to access dead inodes * the test is that same one that e2fsck uses * NeilBrown 1999oct15 */ if (inode->i_nlink == 0) { if ((inode->i_mode == 0 || !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) && ino != EXT4_BOOT_LOADER_INO) { /* this inode is deleted */ ret = -ESTALE; goto bad_inode; } /* The only unlinked inodes we let through here have * valid i_mode and are being read by the orphan * recovery code: that's fine, we're about to complete * the process of deleting those. * OR it is the EXT4_BOOT_LOADER_INO which is * not initialized on a new filesystem. */ } ei->i_flags = le32_to_cpu(raw_inode->i_flags); inode->i_blocks = ext4_inode_blocks(raw_inode, ei); ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo); if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) ei->i_file_acl |= ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32; inode->i_size = ext4_isize(raw_inode); ei->i_disksize = inode->i_size; #ifdef CONFIG_QUOTA ei->i_reserved_quota = 0; #endif inode->i_generation = le32_to_cpu(raw_inode->i_generation); ei->i_block_group = iloc.block_group; ei->i_last_alloc_group = ~0; /* * NOTE! The in-memory inode i_data array is in little-endian order * even on big-endian machines: we do NOT byteswap the block numbers! */ for (block = 0; block < EXT4_N_BLOCKS; block++) ei->i_data[block] = raw_inode->i_block[block]; INIT_LIST_HEAD(&ei->i_orphan); /* * Set transaction id's of transactions that have to be committed * to finish f[data]sync. We set them to currently running transaction * as we cannot be sure that the inode or some of its metadata isn't * part of the transaction - the inode could have been reclaimed and * now it is reread from disk. */ if (journal) { transaction_t *transaction; tid_t tid; read_lock(&journal->j_state_lock); if (journal->j_running_transaction) transaction = journal->j_running_transaction; else transaction = journal->j_committing_transaction; if (transaction) tid = transaction->t_tid; else tid = journal->j_commit_sequence; read_unlock(&journal->j_state_lock); ei->i_sync_tid = tid; ei->i_datasync_tid = tid; } if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { if (ei->i_extra_isize == 0) { /* The extra space is currently unused. Use it. */ ei->i_extra_isize = sizeof(struct ext4_inode) - EXT4_GOOD_OLD_INODE_SIZE; } else { ext4_iget_extra_inode(inode, raw_inode, ei); } } EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode); EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode); EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode); EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode); inode->i_version = le32_to_cpu(raw_inode->i_disk_version); if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) inode->i_version |= (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32; } ret = 0; if (ei->i_file_acl && !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) { EXT4_ERROR_INODE(inode, "bad extended attribute block %llu", ei->i_file_acl); ret = -EIO; goto bad_inode; } else if (!ext4_has_inline_data(inode)) { if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { if ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || (S_ISLNK(inode->i_mode) && !ext4_inode_is_fast_symlink(inode)))) /* Validate extent which is part of inode */ ret = ext4_ext_check_inode(inode); } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || (S_ISLNK(inode->i_mode) && !ext4_inode_is_fast_symlink(inode))) { /* Validate block references which are part of inode */ ret = ext4_ind_check_inode(inode); } } if (ret) goto bad_inode; if (S_ISREG(inode->i_mode)) { inode->i_op = &ext4_file_inode_operations; inode->i_fop = &ext4_file_operations; ext4_set_aops(inode); } else if (S_ISDIR(inode->i_mode)) { inode->i_op = &ext4_dir_inode_operations; inode->i_fop = &ext4_dir_operations; } else if (S_ISLNK(inode->i_mode)) { if (ext4_inode_is_fast_symlink(inode)) { inode->i_op = &ext4_fast_symlink_inode_operations; nd_terminate_link(ei->i_data, inode->i_size, sizeof(ei->i_data) - 1); } else { inode->i_op = &ext4_symlink_inode_operations; ext4_set_aops(inode); } } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { inode->i_op = &ext4_special_inode_operations; if (raw_inode->i_block[0]) init_special_inode(inode, inode->i_mode, old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); else init_special_inode(inode, inode->i_mode, new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); } else if (ino == EXT4_BOOT_LOADER_INO) { make_bad_inode(inode); } else { ret = -EIO; EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode); goto bad_inode; } brelse(iloc.bh); ext4_set_inode_flags(inode); unlock_new_inode(inode); return inode; bad_inode: brelse(iloc.bh); iget_failed(inode); return ERR_PTR(ret); } static int ext4_inode_blocks_set(handle_t *handle, struct ext4_inode *raw_inode, struct ext4_inode_info *ei) { struct inode *inode = &(ei->vfs_inode); u64 i_blocks = inode->i_blocks; struct super_block *sb = inode->i_sb; if (i_blocks <= ~0U) { /* * i_blocks can be represented in a 32 bit variable * as multiple of 512 bytes */ raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); raw_inode->i_blocks_high = 0; ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE); return 0; } if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) return -EFBIG; if (i_blocks <= 0xffffffffffffULL) { /* * i_blocks can be represented in a 48 bit variable * as multiple of 512 bytes */ raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32); ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE); } else { ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE); /* i_block is stored in file system block size */ i_blocks = i_blocks >> (inode->i_blkbits - 9); raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32); } return 0; } /* * Post the struct inode info into an on-disk inode location in the * buffer-cache. This gobbles the caller's reference to the * buffer_head in the inode location struct. * * The caller must have write access to iloc->bh. */ static int ext4_do_update_inode(handle_t *handle, struct inode *inode, struct ext4_iloc *iloc) { struct ext4_inode *raw_inode = ext4_raw_inode(iloc); struct ext4_inode_info *ei = EXT4_I(inode); struct buffer_head *bh = iloc->bh; int err = 0, rc, block; int need_datasync = 0; uid_t i_uid; gid_t i_gid; /* For fields not not tracking in the in-memory inode, * initialise them to zero for new inodes. */ if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); ext4_get_inode_flags(ei); raw_inode->i_mode = cpu_to_le16(inode->i_mode); i_uid = i_uid_read(inode); i_gid = i_gid_read(inode); if (!(test_opt(inode->i_sb, NO_UID32))) { raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid)); raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid)); /* * Fix up interoperability with old kernels. Otherwise, old inodes get * re-used with the upper 16 bits of the uid/gid intact */ if (!ei->i_dtime) { raw_inode->i_uid_high = cpu_to_le16(high_16_bits(i_uid)); raw_inode->i_gid_high = cpu_to_le16(high_16_bits(i_gid)); } else { raw_inode->i_uid_high = 0; raw_inode->i_gid_high = 0; } } else { raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid)); raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid)); raw_inode->i_uid_high = 0; raw_inode->i_gid_high = 0; } raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode); EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode); EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode); EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode); if (ext4_inode_blocks_set(handle, raw_inode, ei)) goto out_brelse; raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF); if (EXT4_SB(inode->i_sb)->s_es->s_creator_os != cpu_to_le32(EXT4_OS_HURD)) raw_inode->i_file_acl_high = cpu_to_le16(ei->i_file_acl >> 32); raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl); if (ei->i_disksize != ext4_isize(raw_inode)) { ext4_isize_set(raw_inode, ei->i_disksize); need_datasync = 1; } if (ei->i_disksize > 0x7fffffffULL) { struct super_block *sb = inode->i_sb; if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_LARGE_FILE) || EXT4_SB(sb)->s_es->s_rev_level == cpu_to_le32(EXT4_GOOD_OLD_REV)) { /* If this is the first large file * created, add a flag to the superblock. */ err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); if (err) goto out_brelse; ext4_update_dynamic_rev(sb); EXT4_SET_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_LARGE_FILE); ext4_handle_sync(handle); err = ext4_handle_dirty_super(handle, sb); } } raw_inode->i_generation = cpu_to_le32(inode->i_generation); if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { if (old_valid_dev(inode->i_rdev)) { raw_inode->i_block[0] = cpu_to_le32(old_encode_dev(inode->i_rdev)); raw_inode->i_block[1] = 0; } else { raw_inode->i_block[0] = 0; raw_inode->i_block[1] = cpu_to_le32(new_encode_dev(inode->i_rdev)); raw_inode->i_block[2] = 0; } } else if (!ext4_has_inline_data(inode)) { for (block = 0; block < EXT4_N_BLOCKS; block++) raw_inode->i_block[block] = ei->i_data[block]; } raw_inode->i_disk_version = cpu_to_le32(inode->i_version); if (ei->i_extra_isize) { if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) raw_inode->i_version_hi = cpu_to_le32(inode->i_version >> 32); raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize); } ext4_inode_csum_set(inode, raw_inode, ei); BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); rc = ext4_handle_dirty_metadata(handle, NULL, bh); if (!err) err = rc; ext4_clear_inode_state(inode, EXT4_STATE_NEW); ext4_update_inode_fsync_trans(handle, inode, need_datasync); out_brelse: brelse(bh); ext4_std_error(inode->i_sb, err); return err; } /* * ext4_write_inode() * * We are called from a few places: * * - Within generic_file_write() for O_SYNC files. * Here, there will be no transaction running. We wait for any running * transaction to commit. * * - Within sys_sync(), kupdate and such. * We wait on commit, if tol to. * * - Within prune_icache() (PF_MEMALLOC == true) * Here we simply return. We can't afford to block kswapd on the * journal commit. * * In all cases it is actually safe for us to return without doing anything, * because the inode has been copied into a raw inode buffer in * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for * knfsd. * * Note that we are absolutely dependent upon all inode dirtiers doing the * right thing: they *must* call mark_inode_dirty() after dirtying info in * which we are interested. * * It would be a bug for them to not do this. The code: * * mark_inode_dirty(inode) * stuff(); * inode->i_size = expr; * * is in error because a kswapd-driven write_inode() could occur while * `stuff()' is running, and the new i_size will be lost. Plus the inode * will no longer be on the superblock's dirty inode list. */ int ext4_write_inode(struct inode *inode, struct writeback_control *wbc) { int err; if (current->flags & PF_MEMALLOC) return 0; if (EXT4_SB(inode->i_sb)->s_journal) { if (ext4_journal_current_handle()) { jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n"); dump_stack(); return -EIO; } if (wbc->sync_mode != WB_SYNC_ALL) return 0; err = ext4_force_commit(inode->i_sb); } else { struct ext4_iloc iloc; err = __ext4_get_inode_loc(inode, &iloc, 0); if (err) return err; if (wbc->sync_mode == WB_SYNC_ALL) sync_dirty_buffer(iloc.bh); if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) { EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr, "IO error syncing inode"); err = -EIO; } brelse(iloc.bh); } return err; } /* * In data=journal mode ext4_journalled_invalidatepage() may fail to invalidate * buffers that are attached to a page stradding i_size and are undergoing * commit. In that case we have to wait for commit to finish and try again. */ static void ext4_wait_for_tail_page_commit(struct inode *inode) { struct page *page; unsigned offset; journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; tid_t commit_tid = 0; int ret; offset = inode->i_size & (PAGE_CACHE_SIZE - 1); /* * All buffers in the last page remain valid? Then there's nothing to * do. We do the check mainly to optimize the common PAGE_CACHE_SIZE == * blocksize case */ if (offset > PAGE_CACHE_SIZE - (1 << inode->i_blkbits)) return; while (1) { page = find_lock_page(inode->i_mapping, inode->i_size >> PAGE_CACHE_SHIFT); if (!page) return; ret = __ext4_journalled_invalidatepage(page, offset, PAGE_CACHE_SIZE - offset); unlock_page(page); page_cache_release(page); if (ret != -EBUSY) return; commit_tid = 0; read_lock(&journal->j_state_lock); if (journal->j_committing_transaction) commit_tid = journal->j_committing_transaction->t_tid; read_unlock(&journal->j_state_lock); if (commit_tid) jbd2_log_wait_commit(journal, commit_tid); } } /* * ext4_setattr() * * Called from notify_change. * * We want to trap VFS attempts to truncate the file as soon as * possible. In particular, we want to make sure that when the VFS * shrinks i_size, we put the inode on the orphan list and modify * i_disksize immediately, so that during the subsequent flushing of * dirty pages and freeing of disk blocks, we can guarantee that any * commit will leave the blocks being flushed in an unused state on * disk. (On recovery, the inode will get truncated and the blocks will * be freed, so we have a strong guarantee that no future commit will * leave these blocks visible to the user.) * * Another thing we have to assure is that if we are in ordered mode * and inode is still attached to the committing transaction, we must * we start writeout of all the dirty pages which are being truncated. * This way we are sure that all the data written in the previous * transaction are already on disk (truncate waits for pages under * writeback). * * Called with inode->i_mutex down. */ int ext4_setattr(struct dentry *dentry, struct iattr *attr) { struct inode *inode = dentry->d_inode; int error, rc = 0; int orphan = 0; const unsigned int ia_valid = attr->ia_valid; error = inode_change_ok(inode, attr); if (error) return error; if (is_quota_modification(inode, attr)) dquot_initialize(inode); if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) || (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) { handle_t *handle; /* (user+group)*(old+new) structure, inode write (sb, * inode block, ? - but truncate inode update has it) */ handle = ext4_journal_start(inode, EXT4_HT_QUOTA, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb) + EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb)) + 3); if (IS_ERR(handle)) { error = PTR_ERR(handle); goto err_out; } error = dquot_transfer(inode, attr); if (error) { ext4_journal_stop(handle); return error; } /* Update corresponding info in inode so that everything is in * one transaction */ if (attr->ia_valid & ATTR_UID) inode->i_uid = attr->ia_uid; if (attr->ia_valid & ATTR_GID) inode->i_gid = attr->ia_gid; error = ext4_mark_inode_dirty(handle, inode); ext4_journal_stop(handle); } if (attr->ia_valid & ATTR_SIZE) { if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); if (attr->ia_size > sbi->s_bitmap_maxbytes) return -EFBIG; } } if (S_ISREG(inode->i_mode) && attr->ia_valid & ATTR_SIZE && (attr->ia_size < inode->i_size)) { handle_t *handle; handle = ext4_journal_start(inode, EXT4_HT_INODE, 3); if (IS_ERR(handle)) { error = PTR_ERR(handle); goto err_out; } if (ext4_handle_valid(handle)) { error = ext4_orphan_add(handle, inode); orphan = 1; } EXT4_I(inode)->i_disksize = attr->ia_size; rc = ext4_mark_inode_dirty(handle, inode); if (!error) error = rc; ext4_journal_stop(handle); if (ext4_should_order_data(inode)) { error = ext4_begin_ordered_truncate(inode, attr->ia_size); if (error) { /* Do as much error cleanup as possible */ handle = ext4_journal_start(inode, EXT4_HT_INODE, 3); if (IS_ERR(handle)) { ext4_orphan_del(NULL, inode); goto err_out; } ext4_orphan_del(handle, inode); orphan = 0; ext4_journal_stop(handle); goto err_out; } } } if (attr->ia_valid & ATTR_SIZE) { if (attr->ia_size != inode->i_size) { loff_t oldsize = inode->i_size; i_size_write(inode, attr->ia_size); /* * Blocks are going to be removed from the inode. Wait * for dio in flight. Temporarily disable * dioread_nolock to prevent livelock. */ if (orphan) { if (!ext4_should_journal_data(inode)) { ext4_inode_block_unlocked_dio(inode); inode_dio_wait(inode); ext4_inode_resume_unlocked_dio(inode); } else ext4_wait_for_tail_page_commit(inode); } /* * Truncate pagecache after we've waited for commit * in data=journal mode to make pages freeable. */ truncate_pagecache(inode, oldsize, inode->i_size); } ext4_truncate(inode); } if (!rc) { setattr_copy(inode, attr); mark_inode_dirty(inode); } /* * If the call to ext4_truncate failed to get a transaction handle at * all, we need to clean up the in-core orphan list manually. */ if (orphan && inode->i_nlink) ext4_orphan_del(NULL, inode); if (!rc && (ia_valid & ATTR_MODE)) rc = ext4_acl_chmod(inode); err_out: ext4_std_error(inode->i_sb, error); if (!error) error = rc; return error; } int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { struct inode *inode; unsigned long long delalloc_blocks; inode = dentry->d_inode; generic_fillattr(inode, stat); /* * We can't update i_blocks if the block allocation is delayed * otherwise in the case of system crash before the real block * allocation is done, we will have i_blocks inconsistent with * on-disk file blocks. * We always keep i_blocks updated together with real * allocation. But to not confuse with user, stat * will return the blocks that include the delayed allocation * blocks for this file. */ delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb), EXT4_I(inode)->i_reserved_data_blocks); stat->blocks += delalloc_blocks << (inode->i_sb->s_blocksize_bits-9); return 0; } static int ext4_index_trans_blocks(struct inode *inode, int lblocks, int pextents) { if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) return ext4_ind_trans_blocks(inode, lblocks); return ext4_ext_index_trans_blocks(inode, pextents); } /* * Account for index blocks, block groups bitmaps and block group * descriptor blocks if modify datablocks and index blocks * worse case, the indexs blocks spread over different block groups * * If datablocks are discontiguous, they are possible to spread over * different block groups too. If they are contiguous, with flexbg, * they could still across block group boundary. * * Also account for superblock, inode, quota and xattr blocks */ static int ext4_meta_trans_blocks(struct inode *inode, int lblocks, int pextents) { ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb); int gdpblocks; int idxblocks; int ret = 0; /* * How many index blocks need to touch to map @lblocks logical blocks * to @pextents physical extents? */ idxblocks = ext4_index_trans_blocks(inode, lblocks, pextents); ret = idxblocks; /* * Now let's see how many group bitmaps and group descriptors need * to account */ groups = idxblocks + pextents; gdpblocks = groups; if (groups > ngroups) groups = ngroups; if (groups > EXT4_SB(inode->i_sb)->s_gdb_count) gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count; /* bitmaps and block group descriptor blocks */ ret += groups + gdpblocks; /* Blocks for super block, inode, quota and xattr blocks */ ret += EXT4_META_TRANS_BLOCKS(inode->i_sb); return ret; } /* * Calculate the total number of credits to reserve to fit * the modification of a single pages into a single transaction, * which may include multiple chunks of block allocations. * * This could be called via ext4_write_begin() * * We need to consider the worse case, when * one new block per extent. */ int ext4_writepage_trans_blocks(struct inode *inode) { int bpp = ext4_journal_blocks_per_page(inode); int ret; ret = ext4_meta_trans_blocks(inode, bpp, bpp); /* Account for data blocks for journalled mode */ if (ext4_should_journal_data(inode)) ret += bpp; return ret; } /* * Calculate the journal credits for a chunk of data modification. * * This is called from DIO, fallocate or whoever calling * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks. * * journal buffers for data blocks are not included here, as DIO * and fallocate do no need to journal data buffers. */ int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks) { return ext4_meta_trans_blocks(inode, nrblocks, 1); } /* * The caller must have previously called ext4_reserve_inode_write(). * Give this, we know that the caller already has write access to iloc->bh. */ int ext4_mark_iloc_dirty(handle_t *handle, struct inode *inode, struct ext4_iloc *iloc) { int err = 0; if (IS_I_VERSION(inode)) inode_inc_iversion(inode); /* the do_update_inode consumes one bh->b_count */ get_bh(iloc->bh); /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */ err = ext4_do_update_inode(handle, inode, iloc); put_bh(iloc->bh); return err; } /* * On success, We end up with an outstanding reference count against * iloc->bh. This _must_ be cleaned up later. */ int ext4_reserve_inode_write(handle_t *handle, struct inode *inode, struct ext4_iloc *iloc) { int err; err = ext4_get_inode_loc(inode, iloc); if (!err) { BUFFER_TRACE(iloc->bh, "get_write_access"); err = ext4_journal_get_write_access(handle, iloc->bh); if (err) { brelse(iloc->bh); iloc->bh = NULL; } } ext4_std_error(inode->i_sb, err); return err; } /* * Expand an inode by new_extra_isize bytes. * Returns 0 on success or negative error number on failure. */ static int ext4_expand_extra_isize(struct inode *inode, unsigned int new_extra_isize, struct ext4_iloc iloc, handle_t *handle) { struct ext4_inode *raw_inode; struct ext4_xattr_ibody_header *header; if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) return 0; raw_inode = ext4_raw_inode(&iloc); header = IHDR(inode, raw_inode); /* No extended attributes present */ if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) || header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) { memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0, new_extra_isize); EXT4_I(inode)->i_extra_isize = new_extra_isize; return 0; } /* try to expand with EAs present */ return ext4_expand_extra_isize_ea(inode, new_extra_isize, raw_inode, handle); } /* * What we do here is to mark the in-core inode as clean with respect to inode * dirtiness (it may still be data-dirty). * This means that the in-core inode may be reaped by prune_icache * without having to perform any I/O. This is a very good thing, * because *any* task may call prune_icache - even ones which * have a transaction open against a different journal. * * Is this cheating? Not really. Sure, we haven't written the * inode out, but prune_icache isn't a user-visible syncing function. * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync) * we start and wait on commits. */ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode) { struct ext4_iloc iloc; struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); static unsigned int mnt_count; int err, ret; might_sleep(); trace_ext4_mark_inode_dirty(inode, _RET_IP_); err = ext4_reserve_inode_write(handle, inode, &iloc); if (ext4_handle_valid(handle) && EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize && !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) { /* * We need extra buffer credits since we may write into EA block * with this same handle. If journal_extend fails, then it will * only result in a minor loss of functionality for that inode. * If this is felt to be critical, then e2fsck should be run to * force a large enough s_min_extra_isize. */ if ((jbd2_journal_extend(handle, EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) { ret = ext4_expand_extra_isize(inode, sbi->s_want_extra_isize, iloc, handle); if (ret) { ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND); if (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count)) { ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete" " some EAs or run e2fsck.", inode->i_ino); mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count); } } } } if (!err) err = ext4_mark_iloc_dirty(handle, inode, &iloc); return err; } /* * ext4_dirty_inode() is called from __mark_inode_dirty() * * We're really interested in the case where a file is being extended. * i_size has been changed by generic_commit_write() and we thus need * to include the updated inode in the current transaction. * * Also, dquot_alloc_block() will always dirty the inode when blocks * are allocated to the file. * * If the inode is marked synchronous, we don't honour that here - doing * so would cause a commit on atime updates, which we don't bother doing. * We handle synchronous inodes at the highest possible level. */ void ext4_dirty_inode(struct inode *inode, int flags) { handle_t *handle; handle = ext4_journal_start(inode, EXT4_HT_INODE, 2); if (IS_ERR(handle)) goto out; ext4_mark_inode_dirty(handle, inode); ext4_journal_stop(handle); out: return; } #if 0 /* * Bind an inode's backing buffer_head into this transaction, to prevent * it from being flushed to disk early. Unlike * ext4_reserve_inode_write, this leaves behind no bh reference and * returns no iloc structure, so the caller needs to repeat the iloc * lookup to mark the inode dirty later. */ static int ext4_pin_inode(handle_t *handle, struct inode *inode) { struct ext4_iloc iloc; int err = 0; if (handle) { err = ext4_get_inode_loc(inode, &iloc); if (!err) { BUFFER_TRACE(iloc.bh, "get_write_access"); err = jbd2_journal_get_write_access(handle, iloc.bh); if (!err) err = ext4_handle_dirty_metadata(handle, NULL, iloc.bh); brelse(iloc.bh); } } ext4_std_error(inode->i_sb, err); return err; } #endif int ext4_change_inode_journal_flag(struct inode *inode, int val) { journal_t *journal; handle_t *handle; int err; /* * We have to be very careful here: changing a data block's * journaling status dynamically is dangerous. If we write a * data block to the journal, change the status and then delete * that block, we risk forgetting to revoke the old log record * from the journal and so a subsequent replay can corrupt data. * So, first we make sure that the journal is empty and that * nobody is changing anything. */ journal = EXT4_JOURNAL(inode); if (!journal) return 0; if (is_journal_aborted(journal)) return -EROFS; /* We have to allocate physical blocks for delalloc blocks * before flushing journal. otherwise delalloc blocks can not * be allocated any more. even more truncate on delalloc blocks * could trigger BUG by flushing delalloc blocks in journal. * There is no delalloc block in non-journal data mode. */ if (val && test_opt(inode->i_sb, DELALLOC)) { err = ext4_alloc_da_blocks(inode); if (err < 0) return err; } /* Wait for all existing dio workers */ ext4_inode_block_unlocked_dio(inode); inode_dio_wait(inode); jbd2_journal_lock_updates(journal); /* * OK, there are no updates running now, and all cached data is * synced to disk. We are now in a completely consistent state * which doesn't have anything in the journal, and we know that * no filesystem updates are running, so it is safe to modify * the inode's in-core data-journaling state flag now. */ if (val) ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA); else { jbd2_journal_flush(journal); ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA); } ext4_set_aops(inode); jbd2_journal_unlock_updates(journal); ext4_inode_resume_unlocked_dio(inode); /* Finally we can mark the inode as dirty. */ handle = ext4_journal_start(inode, EXT4_HT_INODE, 1); if (IS_ERR(handle)) return PTR_ERR(handle); err = ext4_mark_inode_dirty(handle, inode); ext4_handle_sync(handle); ext4_journal_stop(handle); ext4_std_error(inode->i_sb, err); return err; } static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh) { return !buffer_mapped(bh); } int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) { struct page *page = vmf->page; loff_t size; unsigned long len; int ret; struct file *file = vma->vm_file; struct inode *inode = file_inode(file); struct address_space *mapping = inode->i_mapping; handle_t *handle; get_block_t *get_block; int retries = 0; sb_start_pagefault(inode->i_sb); file_update_time(vma->vm_file); /* Delalloc case is easy... */ if (test_opt(inode->i_sb, DELALLOC) && !ext4_should_journal_data(inode) && !ext4_nonda_switch(inode->i_sb)) { do { ret = __block_page_mkwrite(vma, vmf, ext4_da_get_block_prep); } while (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)); goto out_ret; } lock_page(page); size = i_size_read(inode); /* Page got truncated from under us? */ if (page->mapping != mapping || page_offset(page) > size) { unlock_page(page); ret = VM_FAULT_NOPAGE; goto out; } if (page->index == size >> PAGE_CACHE_SHIFT) len = size & ~PAGE_CACHE_MASK; else len = PAGE_CACHE_SIZE; /* * Return if we have all the buffers mapped. This avoids the need to do * journal_start/journal_stop which can block and take a long time */ if (page_has_buffers(page)) { if (!ext4_walk_page_buffers(NULL, page_buffers(page), 0, len, NULL, ext4_bh_unmapped)) { /* Wait so that we don't change page under IO */ wait_for_stable_page(page); ret = VM_FAULT_LOCKED; goto out; } } unlock_page(page); /* OK, we need to fill the hole... */ if (ext4_should_dioread_nolock(inode)) get_block = ext4_get_block_write; else get_block = ext4_get_block; retry_alloc: handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, ext4_writepage_trans_blocks(inode)); if (IS_ERR(handle)) { ret = VM_FAULT_SIGBUS; goto out; } ret = __block_page_mkwrite(vma, vmf, get_block); if (!ret && ext4_should_journal_data(inode)) { if (ext4_walk_page_buffers(handle, page_buffers(page), 0, PAGE_CACHE_SIZE, NULL, do_journal_get_write_access)) { unlock_page(page); ret = VM_FAULT_SIGBUS; ext4_journal_stop(handle); goto out; } ext4_set_inode_state(inode, EXT4_STATE_JDATA); } ext4_journal_stop(handle); if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) goto retry_alloc; out_ret: ret = block_page_mkwrite_return(ret); out: sb_end_pagefault(inode->i_sb); return ret; }