diff options
Diffstat (limited to 'fs/ext3/balloc.c')
| -rw-r--r-- | fs/ext3/balloc.c | 1600 |
1 files changed, 1600 insertions, 0 deletions
diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c new file mode 100644 index 000000000000..ccd632fcc6d8 --- /dev/null +++ b/fs/ext3/balloc.c @@ -0,0 +1,1600 @@ +/* + * linux/fs/ext3/balloc.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) + * + * Enhanced block allocation by Stephen Tweedie (sct@redhat.com), 1993 + * Big-endian to little-endian byte-swapping/bitmaps by + * David S. Miller (davem@caip.rutgers.edu), 1995 + */ + +#include <linux/config.h> +#include <linux/time.h> +#include <linux/fs.h> +#include <linux/jbd.h> +#include <linux/ext3_fs.h> +#include <linux/ext3_jbd.h> +#include <linux/quotaops.h> +#include <linux/buffer_head.h> + +/* + * balloc.c contains the blocks allocation and deallocation routines + */ + +/* + * The free blocks are managed by bitmaps. A file system contains several + * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap + * block for inodes, N blocks for the inode table and data blocks. + * + * The file system contains group descriptors which are located after the + * super block. Each descriptor contains the number of the bitmap block and + * the free blocks count in the block. The descriptors are loaded in memory + * when a file system is mounted (see ext3_read_super). + */ + + +#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) + +struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb, + unsigned int block_group, + struct buffer_head ** bh) +{ + unsigned long group_desc; + unsigned long offset; + struct ext3_group_desc * desc; + struct ext3_sb_info *sbi = EXT3_SB(sb); + + if (block_group >= sbi->s_groups_count) { + ext3_error (sb, "ext3_get_group_desc", + "block_group >= groups_count - " + "block_group = %d, groups_count = %lu", + block_group, sbi->s_groups_count); + + return NULL; + } + smp_rmb(); + + group_desc = block_group >> EXT3_DESC_PER_BLOCK_BITS(sb); + offset = block_group & (EXT3_DESC_PER_BLOCK(sb) - 1); + if (!sbi->s_group_desc[group_desc]) { + ext3_error (sb, "ext3_get_group_desc", + "Group descriptor not loaded - " + "block_group = %d, group_desc = %lu, desc = %lu", + block_group, group_desc, offset); + return NULL; + } + + desc = (struct ext3_group_desc *) sbi->s_group_desc[group_desc]->b_data; + if (bh) + *bh = sbi->s_group_desc[group_desc]; + return desc + offset; +} + +/* + * Read the bitmap for a given block_group, reading into the specified + * slot in the superblock's bitmap cache. + * + * Return buffer_head on success or NULL in case of failure. + */ +static struct buffer_head * +read_block_bitmap(struct super_block *sb, unsigned int block_group) +{ + struct ext3_group_desc * desc; + struct buffer_head * bh = NULL; + + desc = ext3_get_group_desc (sb, block_group, NULL); + if (!desc) + goto error_out; + bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap)); + if (!bh) + ext3_error (sb, "read_block_bitmap", + "Cannot read block bitmap - " + "block_group = %d, block_bitmap = %u", + block_group, le32_to_cpu(desc->bg_block_bitmap)); +error_out: + return bh; +} +/* + * The reservation window structure operations + * -------------------------------------------- + * Operations include: + * dump, find, add, remove, is_empty, find_next_reservable_window, etc. + * + * We use sorted double linked list for the per-filesystem reservation + * window list. (like in vm_region). + * + * Initially, we keep those small operations in the abstract functions, + * so later if we need a better searching tree than double linked-list, + * we could easily switch to that without changing too much + * code. + */ +#if 0 +static void __rsv_window_dump(struct rb_root *root, int verbose, + const char *fn) +{ + struct rb_node *n; + struct ext3_reserve_window_node *rsv, *prev; + int bad; + +restart: + n = rb_first(root); + bad = 0; + prev = NULL; + + printk("Block Allocation Reservation Windows Map (%s):\n", fn); + while (n) { + rsv = list_entry(n, struct ext3_reserve_window_node, rsv_node); + if (verbose) + printk("reservation window 0x%p " + "start: %d, end: %d\n", + rsv, rsv->rsv_start, rsv->rsv_end); + if (rsv->rsv_start && rsv->rsv_start >= rsv->rsv_end) { + printk("Bad reservation %p (start >= end)\n", + rsv); + bad = 1; + } + if (prev && prev->rsv_end >= rsv->rsv_start) { + printk("Bad reservation %p (prev->end >= start)\n", + rsv); + bad = 1; + } + if (bad) { + if (!verbose) { + printk("Restarting reservation walk in verbose mode\n"); + verbose = 1; + goto restart; + } + } + n = rb_next(n); + prev = rsv; + } + printk("Window map complete.\n"); + if (bad) + BUG(); +} +#define rsv_window_dump(root, verbose) \ + __rsv_window_dump((root), (verbose), __FUNCTION__) +#else +#define rsv_window_dump(root, verbose) do {} while (0) +#endif + +static int +goal_in_my_reservation(struct ext3_reserve_window *rsv, int goal, + unsigned int group, struct super_block * sb) +{ + unsigned long group_first_block, group_last_block; + + group_first_block = le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) + + group * EXT3_BLOCKS_PER_GROUP(sb); + group_last_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1; + + if ((rsv->_rsv_start > group_last_block) || + (rsv->_rsv_end < group_first_block)) + return 0; + if ((goal >= 0) && ((goal + group_first_block < rsv->_rsv_start) + || (goal + group_first_block > rsv->_rsv_end))) + return 0; + return 1; +} + +/* + * Find the reserved window which includes the goal, or the previous one + * if the goal is not in any window. + * Returns NULL if there are no windows or if all windows start after the goal. + */ +static struct ext3_reserve_window_node * +search_reserve_window(struct rb_root *root, unsigned long goal) +{ + struct rb_node *n = root->rb_node; + struct ext3_reserve_window_node *rsv; + + if (!n) + return NULL; + + do { + rsv = rb_entry(n, struct ext3_reserve_window_node, rsv_node); + + if (goal < rsv->rsv_start) + n = n->rb_left; + else if (goal > rsv->rsv_end) + n = n->rb_right; + else + return rsv; + } while (n); + /* + * We've fallen off the end of the tree: the goal wasn't inside + * any particular node. OK, the previous node must be to one + * side of the interval containing the goal. If it's the RHS, + * we need to back up one. + */ + if (rsv->rsv_start > goal) { + n = rb_prev(&rsv->rsv_node); + rsv = rb_entry(n, struct ext3_reserve_window_node, rsv_node); + } + return rsv; +} + +void ext3_rsv_window_add(struct super_block *sb, + struct ext3_reserve_window_node *rsv) +{ + struct rb_root *root = &EXT3_SB(sb)->s_rsv_window_root; + struct rb_node *node = &rsv->rsv_node; + unsigned int start = rsv->rsv_start; + + struct rb_node ** p = &root->rb_node; + struct rb_node * parent = NULL; + struct ext3_reserve_window_node *this; + + while (*p) + { + parent = *p; + this = rb_entry(parent, struct ext3_reserve_window_node, rsv_node); + + if (start < this->rsv_start) + p = &(*p)->rb_left; + else if (start > this->rsv_end) + p = &(*p)->rb_right; + else + BUG(); + } + + rb_link_node(node, parent, p); + rb_insert_color(node, root); +} + +static void rsv_window_remove(struct super_block *sb, + struct ext3_reserve_window_node *rsv) +{ + rsv->rsv_start = EXT3_RESERVE_WINDOW_NOT_ALLOCATED; + rsv->rsv_end = EXT3_RESERVE_WINDOW_NOT_ALLOCATED; + rsv->rsv_alloc_hit = 0; + rb_erase(&rsv->rsv_node, &EXT3_SB(sb)->s_rsv_window_root); +} + +static inline int rsv_is_empty(struct ext3_reserve_window *rsv) +{ + /* a valid reservation end block could not be 0 */ + return (rsv->_rsv_end == EXT3_RESERVE_WINDOW_NOT_ALLOCATED); +} +void ext3_init_block_alloc_info(struct inode *inode) +{ + struct ext3_inode_info *ei = EXT3_I(inode); + struct ext3_block_alloc_info *block_i = ei->i_block_alloc_info; + struct super_block *sb = inode->i_sb; + + block_i = kmalloc(sizeof(*block_i), GFP_NOFS); + if (block_i) { + struct ext3_reserve_window_node *rsv = &block_i->rsv_window_node; + + rsv->rsv_start = EXT3_RESERVE_WINDOW_NOT_ALLOCATED; + rsv->rsv_end = EXT3_RESERVE_WINDOW_NOT_ALLOCATED; + + /* + * if filesystem is mounted with NORESERVATION, the goal + * reservation window size is set to zero to indicate + * block reservation is off + */ + if (!test_opt(sb, RESERVATION)) + rsv->rsv_goal_size = 0; + else + rsv->rsv_goal_size = EXT3_DEFAULT_RESERVE_BLOCKS; + rsv->rsv_alloc_hit = 0; + block_i->last_alloc_logical_block = 0; + block_i->last_alloc_physical_block = 0; + } + ei->i_block_alloc_info = block_i; +} + +void ext3_discard_reservation(struct inode *inode) +{ + struct ext3_inode_info *ei = EXT3_I(inode); + struct ext3_block_alloc_info *block_i = ei->i_block_alloc_info; + struct ext3_reserve_window_node *rsv; + spinlock_t *rsv_lock = &EXT3_SB(inode->i_sb)->s_rsv_window_lock; + + if (!block_i) + return; + + rsv = &block_i->rsv_window_node; + if (!rsv_is_empty(&rsv->rsv_window)) { + spin_lock(rsv_lock); + if (!rsv_is_empty(&rsv->rsv_window)) + rsv_window_remove(inode->i_sb, rsv); + spin_unlock(rsv_lock); + } +} + +/* Free given blocks, update quota and i_blocks field */ +void ext3_free_blocks_sb(handle_t *handle, struct super_block *sb, + unsigned long block, unsigned long count, + int *pdquot_freed_blocks) +{ + struct buffer_head *bitmap_bh = NULL; + struct buffer_head *gd_bh; + unsigned long block_group; + unsigned long bit; + unsigned long i; + unsigned long overflow; + struct ext3_group_desc * desc; + struct ext3_super_block * es; + struct ext3_sb_info *sbi; + int err = 0, ret; + unsigned group_freed; + + *pdquot_freed_blocks = 0; + sbi = EXT3_SB(sb); + es = sbi->s_es; + if (block < le32_to_cpu(es->s_first_data_block) || + block + count < block || + block + count > le32_to_cpu(es->s_blocks_count)) { + ext3_error (sb, "ext3_free_blocks", + "Freeing blocks not in datazone - " + "block = %lu, count = %lu", block, count); + goto error_return; + } + + ext3_debug ("freeing block(s) %lu-%lu\n", block, block + count - 1); + +do_more: + overflow = 0; + block_group = (block - le32_to_cpu(es->s_first_data_block)) / + EXT3_BLOCKS_PER_GROUP(sb); + bit = (block - le32_to_cpu(es->s_first_data_block)) % + EXT3_BLOCKS_PER_GROUP(sb); + /* + * Check to see if we are freeing blocks across a group + * boundary. + */ + if (bit + count > EXT3_BLOCKS_PER_GROUP(sb)) { + overflow = bit + count - EXT3_BLOCKS_PER_GROUP(sb); + count -= overflow; + } + brelse(bitmap_bh); + bitmap_bh = read_block_bitmap(sb, block_group); + if (!bitmap_bh) + goto error_return; + desc = ext3_get_group_desc (sb, block_group, &gd_bh); + if (!desc) + goto error_return; + + if (in_range (le32_to_cpu(desc->bg_block_bitmap), block, count) || + in_range (le32_to_cpu(desc->bg_inode_bitmap), block, count) || + in_range (block, le32_to_cpu(desc->bg_inode_table), + sbi->s_itb_per_group) || + in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table), + sbi->s_itb_per_group)) + ext3_error (sb, "ext3_free_blocks", + "Freeing blocks in system zones - " + "Block = %lu, count = %lu", + block, count); + + /* + * We are about to start releasing blocks in the bitmap, + * so we need undo access. + */ + /* @@@ check errors */ + BUFFER_TRACE(bitmap_bh, "getting undo access"); + err = ext3_journal_get_undo_access(handle, bitmap_bh); + if (err) + goto error_return; + + /* + * We are about to modify some metadata. Call the journal APIs + * to unshare ->b_data if a currently-committing transaction is + * using it + */ + BUFFER_TRACE(gd_bh, "get_write_access"); + err = ext3_journal_get_write_access(handle, gd_bh); + if (err) + goto error_return; + + jbd_lock_bh_state(bitmap_bh); + + for (i = 0, group_freed = 0; i < count; i++) { + /* + * An HJ special. This is expensive... + */ +#ifdef CONFIG_JBD_DEBUG + jbd_unlock_bh_state(bitmap_bh); + { + struct buffer_head *debug_bh; + debug_bh = sb_find_get_block(sb, block + i); + if (debug_bh) { + BUFFER_TRACE(debug_bh, "Deleted!"); + if (!bh2jh(bitmap_bh)->b_committed_data) + BUFFER_TRACE(debug_bh, + "No commited data in bitmap"); + BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap"); + __brelse(debug_bh); + } + } + jbd_lock_bh_state(bitmap_bh); +#endif + if (need_resched()) { + jbd_unlock_bh_state(bitmap_bh); + cond_resched(); + jbd_lock_bh_state(bitmap_bh); + } + /* @@@ This prevents newly-allocated data from being + * freed and then reallocated within the same + * transaction. + * + * Ideally we would want to allow that to happen, but to + * do so requires making journal_forget() capable of + * revoking the queued write of a data block, which + * implies blocking on the journal lock. *forget() + * cannot block due to truncate races. + * + * Eventually we can fix this by making journal_forget() + * return a status indicating whether or not it was able + * to revoke the buffer. On successful revoke, it is + * safe not to set the allocation bit in the committed + * bitmap, because we know that there is no outstanding + * activity on the buffer any more and so it is safe to + * reallocate it. + */ + BUFFER_TRACE(bitmap_bh, "set in b_committed_data"); + J_ASSERT_BH(bitmap_bh, + bh2jh(bitmap_bh)->b_committed_data != NULL); + ext3_set_bit_atomic(sb_bgl_lock(sbi, block_group), bit + i, + bh2jh(bitmap_bh)->b_committed_data); + + /* + * We clear the bit in the bitmap after setting the committed + * data bit, because this is the reverse order to that which + * the allocator uses. + */ + BUFFER_TRACE(bitmap_bh, "clear bit"); + if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, block_group), + bit + i, bitmap_bh->b_data)) { + jbd_unlock_bh_state(bitmap_bh); + ext3_error(sb, __FUNCTION__, + "bit already cleared for block %lu", block + i); + jbd_lock_bh_state(bitmap_bh); + BUFFER_TRACE(bitmap_bh, "bit already cleared"); + } else { + group_freed++; + } + } + jbd_unlock_bh_state(bitmap_bh); + + spin_lock(sb_bgl_lock(sbi, block_group)); + desc->bg_free_blocks_count = + cpu_to_le16(le16_to_cpu(desc->bg_free_blocks_count) + + group_freed); + spin_unlock(sb_bgl_lock(sbi, block_group)); + percpu_counter_mod(&sbi->s_freeblocks_counter, count); + + /* We dirtied the bitmap block */ + BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); + err = ext3_journal_dirty_metadata(handle, bitmap_bh); + + /* And the group descriptor block */ + BUFFER_TRACE(gd_bh, "dirtied group descriptor block"); + ret = ext3_journal_dirty_metadata(handle, gd_bh); + if (!err) err = ret; + *pdquot_freed_blocks += group_freed; + + if (overflow && !err) { + block += count; + count = overflow; + goto do_more; + } + sb->s_dirt = 1; +error_return: + brelse(bitmap_bh); + ext3_std_error(sb, err); + return; +} + +/* Free given blocks, update quota and i_blocks field */ +void ext3_free_blocks(handle_t *handle, struct inode *inode, + unsigned long block, unsigned long count) +{ + struct super_block * sb; + int dquot_freed_blocks; + + sb = inode->i_sb; + if (!sb) { + printk ("ext3_free_blocks: nonexistent device"); + return; + } + ext3_free_blocks_sb(handle, sb, block, count, &dquot_freed_blocks); + if (dquot_freed_blocks) + DQUOT_FREE_BLOCK(inode, dquot_freed_blocks); + return; +} + +/* + * For ext3 allocations, we must not reuse any blocks which are + * allocated in the bitmap buffer's "last committed data" copy. This + * prevents deletes from freeing up the page for reuse until we have + * committed the delete transaction. + * + * If we didn't do this, then deleting something and reallocating it as + * data would allow the old block to be overwritten before the + * transaction committed (because we force data to disk before commit). + * This would lead to corruption if we crashed between overwriting the + * data and committing the delete. + * + * @@@ We may want to make this allocation behaviour conditional on + * data-writes at some point, and disable it for metadata allocations or + * sync-data inodes. + */ +static int ext3_test_allocatable(int nr, struct buffer_head *bh) +{ + int ret; + struct journal_head *jh = bh2jh(bh); + + if (ext3_test_bit(nr, bh->b_data)) + return 0; + + jbd_lock_bh_state(bh); + if (!jh->b_committed_data) + ret = 1; + else + ret = !ext3_test_bit(nr, jh->b_committed_data); + jbd_unlock_bh_state(bh); + return ret; +} + +static int +bitmap_search_next_usable_block(int start, struct buffer_head *bh, + int maxblocks) +{ + int next; + struct journal_head *jh = bh2jh(bh); + + /* + * The bitmap search --- search forward alternately through the actual + * bitmap and the last-committed copy until we find a bit free in + * both + */ + while (start < maxblocks) { + next = ext3_find_next_zero_bit(bh->b_data, maxblocks, start); + if (next >= maxblocks) + return -1; + if (ext3_test_allocatable(next, bh)) + return next; + jbd_lock_bh_state(bh); + if (jh->b_committed_data) + start = ext3_find_next_zero_bit(jh->b_committed_data, + maxblocks, next); + jbd_unlock_bh_state(bh); + } + return -1; +} + +/* + * Find an allocatable block in a bitmap. We honour both the bitmap and + * its last-committed copy (if that exists), and perform the "most + * appropriate allocation" algorithm of looking for a free block near + * the initial goal; then for a free byte somewhere in the bitmap; then + * for any free bit in the bitmap. + */ +static int +find_next_usable_block(int start, struct buffer_head *bh, int maxblocks) +{ + int here, next; + char *p, *r; + + if (start > 0) { + /* + * The goal was occupied; search forward for a free + * block within the next XX blocks. + * + * end_goal is more or less random, but it has to be + * less than EXT3_BLOCKS_PER_GROUP. Aligning up to the + * next 64-bit boundary is simple.. + */ + int end_goal = (start + 63) & ~63; + if (end_goal > maxblocks) + end_goal = maxblocks; + here = ext3_find_next_zero_bit(bh->b_data, end_goal, start); + if (here < end_goal && ext3_test_allocatable(here, bh)) + return here; + ext3_debug("Bit not found near goal\n"); + } + + here = start; + if (here < 0) + here = 0; + + p = ((char *)bh->b_data) + (here >> 3); + r = memscan(p, 0, (maxblocks - here + 7) >> 3); + next = (r - ((char *)bh->b_data)) << 3; + + if (next < maxblocks && next >= start && ext3_test_allocatable(next, bh)) + return next; + + /* + * The bitmap search --- search forward alternately through the actual + * bitmap and the last-committed copy until we find a bit free in + * both + */ + here = bitmap_search_next_usable_block(here, bh, maxblocks); + return here; +} + +/* + * We think we can allocate this block in this bitmap. Try to set the bit. + * If that succeeds then check that nobody has allocated and then freed the + * block since we saw that is was not marked in b_committed_data. If it _was_ + * allocated and freed then clear the bit in the bitmap again and return + * zero (failure). + */ +static inline int +claim_block(spinlock_t *lock, int block, struct buffer_head *bh) +{ + struct journal_head *jh = bh2jh(bh); + int ret; + + if (ext3_set_bit_atomic(lock, block, bh->b_data)) + return 0; + jbd_lock_bh_state(bh); + if (jh->b_committed_data && ext3_test_bit(block,jh->b_committed_data)) { + ext3_clear_bit_atomic(lock, block, bh->b_data); + ret = 0; + } else { + ret = 1; + } + jbd_unlock_bh_state(bh); + return ret; +} + +/* + * If we failed to allocate the desired block then we may end up crossing to a + * new bitmap. In that case we must release write access to the old one via + * ext3_journal_release_buffer(), else we'll run out of credits. + */ +static int +ext3_try_to_allocate(struct super_block *sb, handle_t *handle, int group, + struct buffer_head *bitmap_bh, int goal, struct ext3_reserve_window *my_rsv) +{ + int group_first_block, start, end; + + /* we do allocation within the reservation window if we have a window */ + if (my_rsv) { + group_first_block = + le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) + + group * EXT3_BLOCKS_PER_GROUP(sb); + if (my_rsv->_rsv_start >= group_first_block) + start = my_rsv->_rsv_start - group_first_block; + else + /* reservation window cross group boundary */ + start = 0; + end = my_rsv->_rsv_end - group_first_block + 1; + if (end > EXT3_BLOCKS_PER_GROUP(sb)) + /* reservation window crosses group boundary */ + end = EXT3_BLOCKS_PER_GROUP(sb); + if ((start <= goal) && (goal < end)) + start = goal; + else + goal = -1; + } else { + if (goal > 0) + start = goal; + else + start = 0; + end = EXT3_BLOCKS_PER_GROUP(sb); + } + + BUG_ON(start > EXT3_BLOCKS_PER_GROUP(sb)); + +repeat: + if (goal < 0 || !ext3_test_allocatable(goal, bitmap_bh)) { + goal = find_next_usable_block(start, bitmap_bh, end); + if (goal < 0) + goto fail_access; + if (!my_rsv) { + int i; + + for (i = 0; i < 7 && goal > start && + ext3_test_allocatable(goal - 1, + bitmap_bh); + i++, goal--) + ; + } + } + start = goal; + + if (!claim_block(sb_bgl_lock(EXT3_SB(sb), group), goal, bitmap_bh)) { + /* + * The block was allocated by another thread, or it was + * allocated and then freed by another thread + */ + start++; + goal++; + if (start >= end) + goto fail_access; + goto repeat; + } + return goal; +fail_access: + return -1; +} + +/** + * find_next_reservable_window(): + * find a reservable space within the given range. + * It does not allocate the reservation window for now: + * alloc_new_reservation() will do the work later. + * + * @search_head: the head of the searching list; + * This is not necessarily the list head of the whole filesystem + * + * We have both head and start_block to assist the search + * for the reservable space. The list starts from head, + * but we will shift to the place where start_block is, + * then start from there, when looking for a reservable space. + * + * @size: the target new reservation window size + * + * @group_first_block: the first block we consider to start + * the real search from + * + * @last_block: + * the maximum block number that our goal reservable space + * could start from. This is normally the last block in this + * group. The search will end when we found the start of next + * possible reservable space is out of this boundary. + * This could handle the cross boundary reservation window + * request. + * + * basically we search from the given range, rather than the whole + * reservation double linked list, (start_block, last_block) + * to find a free region that is of my size and has not + * been reserved. + * + * on succeed, it returns the reservation window to be appended to. + * failed, return NULL. + */ +static struct ext3_reserve_window_node *find_next_reservable_window( + struct ext3_reserve_window_node *search_head, + unsigned long size, int *start_block, + int last_block) +{ + struct rb_node *next; + struct ext3_reserve_window_node *rsv, *prev; + int cur; + + /* TODO: make the start of the reservation window byte-aligned */ + /* cur = *start_block & ~7;*/ + cur = *start_block; + rsv = search_head; + if (!rsv) + return NULL; + + while (1) { + if (cur <= rsv->rsv_end) + cur = rsv->rsv_end + 1; + + /* TODO? + * in the case we could not find a reservable space + * that is what is expected, during the re-search, we could + * remember what's the largest reservable space we could have + * and return that one. + * + * For now it will fail if we could not find the reservable + * space with expected-size (or more)... + */ + if (cur > last_block) + return NULL; /* fail */ + + prev = rsv; + next = rb_next(&rsv->rsv_node); + rsv = list_entry(next, struct ext3_reserve_window_node, rsv_node); + + /* + * Reached the last reservation, we can just append to the + * previous one. + */ + if (!next) + break; + + if (cur + size <= rsv->rsv_start) { + /* + * Found a reserveable space big enough. We could + * have a reservation across the group boundary here + */ + break; + } + } + /* + * we come here either : + * when we reach the end of the whole list, + * and there is empty reservable space after last entry in the list. + * append it to the end of the list. + * + * or we found one reservable space in the middle of the list, + * return the reservation window that we could append to. + * succeed. + */ + *start_block = cur; + return prev; +} + +/** + * alloc_new_reservation()--allocate a new reservation window + * + * To make a new reservation, we search part of the filesystem + * reservation list (the list that inside the group). We try to + * allocate a new reservation window near the allocation goal, + * or the beginning of the group, if there is no goal. + * + * We first find a reservable space after the goal, then from + * there, we check the bitmap for the first free block after + * it. If there is no free block until the end of group, then the + * whole group is full, we failed. Otherwise, check if the free + * block is inside the expected reservable space, if so, we + * succeed. + * If the first free block is outside the reservable space, then + * start from the first free block, we search for next available + * space, and go on. + * + * on succeed, a new reservation will be found and inserted into the list + * It contains at least one free block, and it does not overlap with other + * reservation windows. + * + * failed: we failed to find a reservation window in this group + * + * @rsv: the reservation + * + * @goal: The goal (group-relative). It is where the search for a + * free reservable space should start from. + * if we have a goal(goal >0 ), then start from there, + * no goal(goal = -1), we start from the first block + * of the group. + * + * @sb: the super block + * @group: the group we are trying to allocate in + * @bitmap_bh: the block group block bitmap + */ +static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv, + int goal, struct super_block *sb, + unsigned int group, struct buffer_head *bitmap_bh) +{ + struct ext3_reserve_window_node *search_head; + int group_first_block, group_end_block, start_block; + int first_free_block; + int reservable_space_start; + struct ext3_reserve_window_node *prev_rsv; + struct rb_root *fs_rsv_root = &EXT3_SB(sb)->s_rsv_window_root; + unsigned long size; + + group_first_block = le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) + + group * EXT3_BLOCKS_PER_GROUP(sb); + group_end_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1; + + if (goal < 0) + start_block = group_first_block; + else + start_block = goal + group_first_block; + + size = my_rsv->rsv_goal_size; + if (!rsv_is_empty(&my_rsv->rsv_window)) { + /* + * if the old reservation is cross group boundary + * and if the goal is inside the old reservation window, + * we will come here when we just failed to allocate from + * the first part of the window. We still have another part + * that belongs to the next group. In this case, there is no + * point to discard our window and try to allocate a new one + * in this group(which will fail). we should + * keep the reservation window, just simply move on. + * + * Maybe we could shift the start block of the reservation + * window to the first block of next group. + */ + + if ((my_rsv->rsv_start <= group_end_block) && + (my_rsv->rsv_end > group_end_block) && + (start_block >= my_rsv->rsv_start)) + return -1; + + if ((my_rsv->rsv_alloc_hit > + (my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) { + /* + * if we previously allocation hit ration is greater than half + * we double the size of reservation window next time + * otherwise keep the same + */ + size = size * 2; + if (size > EXT3_MAX_RESERVE_BLOCKS) + size = EXT3_MAX_RESERVE_BLOCKS; + my_rsv->rsv_goal_size= size; + } + } + /* + * shift the search start to the window near the goal block + */ + search_head = search_reserve_window(fs_rsv_root, start_block); + + /* + * find_next_reservable_window() simply finds a reservable window + * inside the given range(start_block, group_end_block). + * + * To make sure the reservation window has a free bit inside it, we + * need to check the bitmap after we found a reservable window. + */ +retry: + prev_rsv = find_next_reservable_window(search_head, size, + &start_block, group_end_block); + if (prev_rsv == NULL) + goto failed; + reservable_space_start = start_block; + /* + * On success, find_next_reservable_window() returns the + * reservation window where there is a reservable space after it. + * Before we reserve this reservable space, we need + * to make sure there is at least a free block inside this region. + * + * searching the first free bit on the block bitmap and copy of + * last committed bitmap alternatively, until we found a allocatable + * block. Search start from the start block of the reservable space + * we just found. + */ + first_free_block = bitmap_search_next_usable_block( + reservable_space_start - group_first_block, + bitmap_bh, group_end_block - group_first_block + 1); + + if (first_free_block < 0) { + /* + * no free block left on the bitmap, no point + * to reserve the space. return failed. + */ + goto failed; + } + start_block = first_free_block + group_first_block; + /* + * check if the first free block is within the + * free space we just found + */ + if ((start_block >= reservable_space_start) && + (start_block < reservable_space_start + size)) + goto found_rsv_window; + /* + * if the first free bit we found is out of the reservable space + * this means there is no free block on the reservable space + * we should continue search for next reservable space, + * start from where the free block is, + * we also shift the list head to where we stopped last time + */ + search_head = prev_rsv; + goto retry; + +found_rsv_window: + /* + * great! the reservable space contains some free blocks. + * if the search returns that we should add the new + * window just next to where the old window, we don't + * need to remove the old window first then add it to the + * same place, just update the new start and new end. + */ + if (my_rsv != prev_rsv) { + if (!rsv_is_empty(&my_rsv->rsv_window)) + rsv_window_remove(sb, my_rsv); + } + my_rsv->rsv_start = reservable_space_start; + my_rsv->rsv_end = my_rsv->rsv_start + size - 1; + my_rsv->rsv_alloc_hit = 0; + if (my_rsv != prev_rsv) { + ext3_rsv_window_add(sb, my_rsv); + } + return 0; /* succeed */ +failed: + /* + * failed to find a new reservation window in the current + * group, remove the current(stale) reservation window + * if there is any + */ + if (!rsv_is_empty(&my_rsv->rsv_window)) + rsv_window_remove(sb, my_rsv); + return -1; /* failed */ +} + +/* + * This is the main function used to allocate a new block and its reservation + * window. + * + * Each time when a new block allocation is need, first try to allocate from + * its own reservation. If it does not have a reservation window, instead of + * looking for a free bit on bitmap first, then look up the reservation list to + * see if it is inside somebody else's reservation window, we try to allocate a + * reservation window for it starting from the goal first. Then do the block + * allocation within the reservation window. + * + * This will avoid keeping on searching the reservation list again and + * again when someboday is looking for a free block (without + * reservation), and there are lots of free blocks, but they are all + * being reserved. + * + * We use a sorted double linked list for the per-filesystem reservation list. + * The insert, remove and find a free space(non-reserved) operations for the + * sorted double linked list should be fast. + * + */ +static int +ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle, + unsigned int group, struct buffer_head *bitmap_bh, + int goal, struct ext3_reserve_window_node * my_rsv, + int *errp) +{ + spinlock_t *rsv_lock; + unsigned long group_first_block; + int ret = 0; + int fatal; + + *errp = 0; + + /* + * Make sure we use undo access for the bitmap, because it is critical + * that we do the frozen_data COW on bitmap buffers in all cases even + * if the buffer is in BJ_Forget state in the committing transaction. + */ + BUFFER_TRACE(bitmap_bh, "get undo access for new block"); + fatal = ext3_journal_get_undo_access(handle, bitmap_bh); + if (fatal) { + *errp = fatal; + return -1; + } + + /* + * we don't deal with reservation when + * filesystem is mounted without reservation + * or the file is not a regular file + * or last attempt to allocate a block with reservation turned on failed + */ + if (my_rsv == NULL ) { + ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, goal, NULL); + goto out; + } + rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock; + /* + * goal is a group relative block number (if there is a goal) + * 0 < goal < EXT3_BLOCKS_PER_GROUP(sb) + * first block is a filesystem wide block number + * first block is the block number of the first block in this group + */ + group_first_block = le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) + + group * EXT3_BLOCKS_PER_GROUP(sb); + + /* + * Basically we will allocate a new block from inode's reservation + * window. + * + * We need to allocate a new reservation window, if: + * a) inode does not have a reservation window; or + * b) last attempt to allocate a block from existing reservation + * failed; or + * c) we come here with a goal and with a reservation window + * + * We do not need to allocate a new reservation window if we come here + * at the beginning with a goal and the goal is inside the window, or + * we don't have a goal but already have a reservation window. + * then we could go to allocate from the reservation window directly. + */ + while (1) { + struct ext3_reserve_window rsv_copy; + + rsv_copy._rsv_start = my_rsv->rsv_start; + rsv_copy._rsv_end = my_rsv->rsv_end; + + if (rsv_is_empty(&rsv_copy) || (ret < 0) || + !goal_in_my_reservation(&rsv_copy, goal, group, sb)) { + spin_lock(rsv_lock); + ret = alloc_new_reservation(my_rsv, goal, sb, + group, bitmap_bh); + rsv_copy._rsv_start = my_rsv->rsv_start; + rsv_copy._rsv_end = my_rsv->rsv_end; + spin_unlock(rsv_lock); + if (ret < 0) + break; /* failed */ + + if (!goal_in_my_reservation(&rsv_copy, goal, group, sb)) + goal = -1; + } + if ((rsv_copy._rsv_start >= group_first_block + EXT3_BLOCKS_PER_GROUP(sb)) + || (rsv_copy._rsv_end < group_first_block)) + BUG(); + ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, goal, + &rsv_copy); + if (ret >= 0) { + my_rsv->rsv_alloc_hit++; + break; /* succeed */ + } + } +out: + if (ret >= 0) { + BUFFER_TRACE(bitmap_bh, "journal_dirty_metadata for " + "bitmap block"); + fatal = ext3_journal_dirty_metadata(handle, bitmap_bh); + if (fatal) { + *errp = fatal; + return -1; + } + return ret; + } + + BUFFER_TRACE(bitmap_bh, "journal_release_buffer"); + ext3_journal_release_buffer(handle, bitmap_bh); + return ret; +} + +static int ext3_has_free_blocks(struct ext3_sb_info *sbi) +{ + int free_blocks, root_blocks; + + free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); + root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count); + if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) && + sbi->s_resuid != current->fsuid && + (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) { + return 0; + } + return 1; +} + +/* + * ext3_should_retry_alloc() is called when ENOSPC is returned, and if + * it is profitable to retry the operation, this function will wait + * for the current or commiting transaction to complete, and then + * return TRUE. + */ +int ext3_should_retry_alloc(struct super_block *sb, int *retries) +{ + if (!ext3_has_free_blocks(EXT3_SB(sb)) || (*retries)++ > 3) + return 0; + + jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id); + + return journal_force_commit_nested(EXT3_SB(sb)->s_journal); +} + +/* + * ext3_new_block uses a goal block to assist allocation. If the goal is + * free, or there is a free block within 32 blocks of the goal, that block + * is allocated. Otherwise a forward search is made for a free block; within + * each block group the search first looks for an entire free byte in the block + * bitmap, and then for any free bit if that fails. + * This function also updates quota and i_blocks field. + */ +int ext3_new_block(handle_t *handle, struct inode *inode, + unsigned long goal, int *errp) +{ + struct buffer_head *bitmap_bh = NULL; + struct buffer_head *gdp_bh; + int group_no; + int goal_group; + int ret_block; + int bgi; /* blockgroup iteration index */ + int target_block; + int fatal = 0, err; + int performed_allocation = 0; + int free_blocks; + struct super_block *sb; + struct ext3_group_desc *gdp; + struct ext3_super_block *es; + struct ext3_sb_info *sbi; + struct ext3_reserve_window_node *my_rsv = NULL; + struct ext3_block_alloc_info *block_i; + unsigned short windowsz = 0; +#ifdef EXT3FS_DEBUG + static int goal_hits, goal_attempts; +#endif + unsigned long ngroups; + + *errp = -ENOSPC; + sb = inode->i_sb; + if (!sb) { + printk("ext3_new_block: nonexistent device"); + return 0; + } + + /* + * Check quota for allocation of this block. + */ + if (DQUOT_ALLOC_BLOCK(inode, 1)) { + *errp = -EDQUOT; + return 0; + } + + sbi = EXT3_SB(sb); + es = EXT3_SB(sb)->s_es; + ext3_debug("goal=%lu.\n", goal); + /* + * Allocate a block from reservation only when + * filesystem is mounted with reservation(default,-o reservation), and + * it's a regular file, and + * the desired window size is greater than 0 (One could use ioctl + * command EXT3_IOC_SETRSVSZ to set the window size to 0 to turn off + * reservation on that particular file) + */ + block_i = EXT3_I(inode)->i_block_alloc_info; + if (block_i && ((windowsz = block_i->rsv_window_node.rsv_goal_size) > 0)) + my_rsv = &block_i->rsv_window_node; + + if (!ext3_has_free_blocks(sbi)) { + *errp = -ENOSPC; + goto out; + } + + /* + * First, test whether the goal block is free. + */ + if (goal < le32_to_cpu(es->s_first_data_block) || + goal >= le32_to_cpu(es->s_blocks_count)) + goal = le32_to_cpu(es->s_first_data_block); + group_no = (goal - le32_to_cpu(es->s_first_data_block)) / + EXT3_BLOCKS_PER_GROUP(sb); + gdp = ext3_get_group_desc(sb, group_no, &gdp_bh); + if (!gdp) + goto io_error; + + goal_group = group_no; +retry: + free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); + /* + * if there is not enough free blocks to make a new resevation + * turn off reservation for this allocation + */ + if (my_rsv && (free_blocks < windowsz) + && (rsv_is_empty(&my_rsv->rsv_window))) + my_rsv = NULL; + + if (free_blocks > 0) { + ret_block = ((goal - le32_to_cpu(es->s_first_data_block)) % + EXT3_BLOCKS_PER_GROUP(sb)); + bitmap_bh = read_block_bitmap(sb, group_no); + if (!bitmap_bh) + goto io_error; + ret_block = ext3_try_to_allocate_with_rsv(sb, handle, group_no, + bitmap_bh, ret_block, my_rsv, &fatal); + if (fatal) + goto out; + if (ret_block >= 0) + goto allocated; + } + + ngroups = EXT3_SB(sb)->s_groups_count; + smp_rmb(); + + /* + * Now search the rest of the groups. We assume that + * i and gdp correctly point to the last group visited. + */ + for (bgi = 0; bgi < ngroups; bgi++) { + group_no++; + if (group_no >= ngroups) + group_no = 0; + gdp = ext3_get_group_desc(sb, group_no, &gdp_bh); + if (!gdp) { + *errp = -EIO; + goto out; + } + free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); + /* + * skip this group if the number of + * free blocks is less than half of the reservation + * window size. + */ + if (free_blocks <= (windowsz/2)) + continue; + + brelse(bitmap_bh); + bitmap_bh = read_block_bitmap(sb, group_no); + if (!bitmap_bh) + goto io_error; + ret_block = ext3_try_to_allocate_with_rsv(sb, handle, group_no, + bitmap_bh, -1, my_rsv, &fatal); + if (fatal) + goto out; + if (ret_block >= 0) + goto allocated; + } + /* + * We may end up a bogus ealier ENOSPC error due to + * filesystem is "full" of reservations, but + * there maybe indeed free blocks avaliable on disk + * In this case, we just forget about the reservations + * just do block allocation as without reservations. + */ + if (my_rsv) { + my_rsv = NULL; + group_no = goal_group; + goto retry; + } + /* No space left on the device */ + *errp = -ENOSPC; + goto out; + +allocated: + + ext3_debug("using block group %d(%d)\n", + group_no, gdp->bg_free_blocks_count); + + BUFFER_TRACE(gdp_bh, "get_write_access"); + fatal = ext3_journal_get_write_access(handle, gdp_bh); + if (fatal) + goto out; + + target_block = ret_block + group_no * EXT3_BLOCKS_PER_GROUP(sb) + + le32_to_cpu(es->s_first_data_block); + + if (target_block == le32_to_cpu(gdp->bg_block_bitmap) || + target_block == le32_to_cpu(gdp->bg_inode_bitmap) || + in_range(target_block, le32_to_cpu(gdp->bg_inode_table), + EXT3_SB(sb)->s_itb_per_group)) + ext3_error(sb, "ext3_new_block", + "Allocating block in system zone - " + "block = %u", target_block); + + performed_allocation = 1; + +#ifdef CONFIG_JBD_DEBUG + { + struct buffer_head *debug_bh; + + /* Record bitmap buffer state in the newly allocated block */ + debug_bh = sb_find_get_block(sb, target_block); + if (debug_bh) { + BUFFER_TRACE(debug_bh, "state when allocated"); + BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap state"); + brelse(debug_bh); + } + } + jbd_lock_bh_state(bitmap_bh); + spin_lock(sb_bgl_lock(sbi, group_no)); + if (buffer_jbd(bitmap_bh) && bh2jh(bitmap_bh)->b_committed_data) { + if (ext3_test_bit(ret_block, + bh2jh(bitmap_bh)->b_committed_data)) { + printk("%s: block was unexpectedly set in " + "b_committed_data\n", __FUNCTION__); + } + } + ext3_debug("found bit %d\n", ret_block); + spin_unlock(sb_bgl_lock(sbi, group_no)); + jbd_unlock_bh_state(bitmap_bh); +#endif + + /* ret_block was blockgroup-relative. Now it becomes fs-relative */ + ret_block = target_block; + + if (ret_block >= le32_to_cpu(es->s_blocks_count)) { + ext3_error(sb, "ext3_new_block", + "block(%d) >= blocks count(%d) - " + "block_group = %d, es == %p ", ret_block, + le32_to_cpu(es->s_blocks_count), group_no, es); + goto out; + } + + /* + * It is up to the caller to add the new buffer to a journal + * list of some description. We don't know in advance whether + * the caller wants to use it as metadata or data. + */ + ext3_debug("allocating block %d. Goal hits %d of %d.\n", + ret_block, goal_hits, goal_attempts); + + spin_lock(sb_bgl_lock(sbi, group_no)); + gdp->bg_free_blocks_count = + cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) - 1); + spin_unlock(sb_bgl_lock(sbi, group_no)); + percpu_counter_mod(&sbi->s_freeblocks_counter, -1); + + BUFFER_TRACE(gdp_bh, "journal_dirty_metadata for group descriptor"); + err = ext3_journal_dirty_metadata(handle, gdp_bh); + if (!fatal) + fatal = err; + + sb->s_dirt = 1; + if (fatal) + goto out; + + *errp = 0; + brelse(bitmap_bh); + return ret_block; + +io_error: + *errp = -EIO; +out: + if (fatal) { + *errp = fatal; + ext3_std_error(sb, fatal); + } + /* + * Undo the block allocation + */ + if (!performed_allocation) + DQUOT_FREE_BLOCK(inode, 1); + brelse(bitmap_bh); + return 0; +} + +unsigned long ext3_count_free_blocks(struct super_block *sb) +{ + unsigned long desc_count; + struct ext3_group_desc *gdp; + int i; + unsigned long ngroups; +#ifdef EXT3FS_DEBUG + struct ext3_super_block *es; + unsigned long bitmap_count, x; + struct buffer_head *bitmap_bh = NULL; + + lock_super(sb); + es = EXT3_SB(sb)->s_es; + desc_count = 0; + bitmap_count = 0; + gdp = NULL; + for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) { + gdp = ext3_get_group_desc(sb, i, NULL); + if (!gdp) + continue; + desc_count += le16_to_cpu(gdp->bg_free_blocks_count); + brelse(bitmap_bh); + bitmap_bh = read_block_bitmap(sb, i); + if (bitmap_bh == NULL) + continue; + + x = ext3_count_free(bitmap_bh, sb->s_blocksize); + printk("group %d: stored = %d, counted = %lu\n", + i, le16_to_cpu(gdp->bg_free_blocks_count), x); + bitmap_count += x; + } + brelse(bitmap_bh); + printk("ext3_count_free_blocks: stored = %u, computed = %lu, %lu\n", + le32_to_cpu(es->s_free_blocks_count), desc_count, bitmap_count); + unlock_super(sb); + return bitmap_count; +#else + desc_count = 0; + ngroups = EXT3_SB(sb)->s_groups_count; + smp_rmb(); + for (i = 0; i < ngroups; i++) { + gdp = ext3_get_group_desc(sb, i, NULL); + if (!gdp) + continue; + desc_count += le16_to_cpu(gdp->bg_free_blocks_count); + } + + return desc_count; +#endif +} + +static inline int +block_in_use(unsigned long block, struct super_block *sb, unsigned char *map) +{ + return ext3_test_bit ((block - + le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block)) % + EXT3_BLOCKS_PER_GROUP(sb), map); +} + +static inline int test_root(int a, int b) +{ + int num = b; + + while (a > num) + num *= b; + return num == a; +} + +static int ext3_group_sparse(int group) +{ + if (group <= 1) + return 1; + if (!(group & 1)) + return 0; + return (test_root(group, 7) || test_root(group, 5) || + test_root(group, 3)); +} + +/** + * ext3_bg_has_super - number of blocks used by the superblock in group + * @sb: superblock for filesystem + * @group: group number to check + * + * Return the number of blocks used by the superblock (primary or backup) + * in this group. Currently this will be only 0 or 1. + */ +int ext3_bg_has_super(struct super_block *sb, int group) +{ + if (EXT3_HAS_RO_COMPAT_FEATURE(sb,EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)&& + !ext3_group_sparse(group)) + return 0; + return 1; +} + +/** + * ext3_bg_num_gdb - number of blocks used by the group table in group + * @sb: superblock for filesystem + * @group: group number to check + * + * Return the number of blocks used by the group descriptor table + * (primary or backup) in this group. In the future there may be a + * different number of descriptor blocks in each group. + */ +unsigned long ext3_bg_num_gdb(struct super_block *sb, int group) +{ + if (EXT3_HAS_RO_COMPAT_FEATURE(sb,EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)&& + !ext3_group_sparse(group)) + return 0; + return EXT3_SB(sb)->s_gdb_count; +} + +#ifdef CONFIG_EXT3_CHECK +/* Called at mount-time, super-block is locked */ +void ext3_check_blocks_bitmap (struct super_block * sb) +{ + struct ext3_super_block *es; + unsigned long desc_count, bitmap_count, x, j; + unsigned long desc_blocks; + struct buffer_head *bitmap_bh = NULL; + struct ext3_group_desc *gdp; + int i; + + es = EXT3_SB(sb)->s_es; + desc_count = 0; + bitmap_count = 0; + gdp = NULL; + for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) { + gdp = ext3_get_group_desc (sb, i, NULL); + if (!gdp) + continue; + desc_count += le16_to_cpu(gdp->bg_free_blocks_count); + brelse(bitmap_bh); + bitmap_bh = read_block_bitmap(sb, i); + if (bitmap_bh == NULL) + continue; + + if (ext3_bg_has_super(sb, i) && + !ext3_test_bit(0, bitmap_bh->b_data)) + ext3_error(sb, __FUNCTION__, + "Superblock in group %d is marked free", i); + + desc_blocks = ext3_bg_num_gdb(sb, i); + for (j = 0; j < desc_blocks; j++) + if (!ext3_test_bit(j + 1, bitmap_bh->b_data)) + ext3_error(sb, __FUNCTION__, + "Descriptor block #%ld in group " + "%d is marked free", j, i); + + if (!block_in_use (le32_to_cpu(gdp->bg_block_bitmap), + sb, bitmap_bh->b_data)) + ext3_error (sb, "ext3_check_blocks_bitmap", + "Block bitmap for group %d is marked free", + i); + + if (!block_in_use (le32_to_cpu(gdp->bg_inode_bitmap), + sb, bitmap_bh->b_data)) + ext3_error (sb, "ext3_check_blocks_bitmap", + "Inode bitmap for group %d is marked free", + i); + + for (j = 0; j < EXT3_SB(sb)->s_itb_per_group; j++) + if (!block_in_use (le32_to_cpu(gdp->bg_inode_table) + j, + sb, bitmap_bh->b_data)) + ext3_error (sb, "ext3_check_blocks_bitmap", + "Block #%d of the inode table in " + "group %d is marked free", j, i); + + x = ext3_count_free(bitmap_bh, sb->s_blocksize); + if (le16_to_cpu(gdp->bg_free_blocks_count) != x) + ext3_error (sb, "ext3_check_blocks_bitmap", + "Wrong free blocks count for group %d, " + "stored = %d, counted = %lu", i, + le16_to_cpu(gdp->bg_free_blocks_count), x); + bitmap_count += x; + } + brelse(bitmap_bh); + if (le32_to_cpu(es->s_free_blocks_count) != bitmap_count) + ext3_error (sb, "ext3_check_blocks_bitmap", + "Wrong free blocks count in super block, " + "stored = %lu, counted = %lu", + (unsigned long)le32_to_cpu(es->s_free_blocks_count), + bitmap_count); +} +#endif |