diff options
Diffstat (limited to 'fs/logfs/super.c')
| -rw-r--r-- | fs/logfs/super.c | 653 |
1 files changed, 0 insertions, 653 deletions
diff --git a/fs/logfs/super.c b/fs/logfs/super.c deleted file mode 100644 index 5751082dba52..000000000000 --- a/fs/logfs/super.c +++ /dev/null @@ -1,653 +0,0 @@ -/* - * fs/logfs/super.c - * - * As should be obvious for Linux kernel code, license is GPLv2 - * - * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org> - * - * Generally contains mount/umount code and also serves as a dump area for - * any functions that don't fit elsewhere and neither justify a file of their - * own. - */ -#include "logfs.h" -#include <linux/bio.h> -#include <linux/slab.h> -#include <linux/blkdev.h> -#include <linux/module.h> -#include <linux/mtd/mtd.h> -#include <linux/statfs.h> -#include <linux/buffer_head.h> - -static DEFINE_MUTEX(emergency_mutex); -static struct page *emergency_page; - -struct page *emergency_read_begin(struct address_space *mapping, pgoff_t index) -{ - filler_t *filler = (filler_t *)mapping->a_ops->readpage; - struct page *page; - int err; - - page = read_cache_page(mapping, index, filler, NULL); - if (page) - return page; - - /* No more pages available, switch to emergency page */ - printk(KERN_INFO"Logfs: Using emergency page\n"); - mutex_lock(&emergency_mutex); - err = filler(NULL, emergency_page); - if (err) { - mutex_unlock(&emergency_mutex); - printk(KERN_EMERG"Logfs: Error reading emergency page\n"); - return ERR_PTR(err); - } - return emergency_page; -} - -void emergency_read_end(struct page *page) -{ - if (page == emergency_page) - mutex_unlock(&emergency_mutex); - else - put_page(page); -} - -static void dump_segfile(struct super_block *sb) -{ - struct logfs_super *super = logfs_super(sb); - struct logfs_segment_entry se; - u32 segno; - - for (segno = 0; segno < super->s_no_segs; segno++) { - logfs_get_segment_entry(sb, segno, &se); - printk("%3x: %6x %8x", segno, be32_to_cpu(se.ec_level), - be32_to_cpu(se.valid)); - if (++segno < super->s_no_segs) { - logfs_get_segment_entry(sb, segno, &se); - printk(" %6x %8x", be32_to_cpu(se.ec_level), - be32_to_cpu(se.valid)); - } - if (++segno < super->s_no_segs) { - logfs_get_segment_entry(sb, segno, &se); - printk(" %6x %8x", be32_to_cpu(se.ec_level), - be32_to_cpu(se.valid)); - } - if (++segno < super->s_no_segs) { - logfs_get_segment_entry(sb, segno, &se); - printk(" %6x %8x", be32_to_cpu(se.ec_level), - be32_to_cpu(se.valid)); - } - printk("\n"); - } -} - -/* - * logfs_crash_dump - dump debug information to device - * - * The LogFS superblock only occupies part of a segment. This function will - * write as much debug information as it can gather into the spare space. - */ -void logfs_crash_dump(struct super_block *sb) -{ - dump_segfile(sb); -} - -/* - * FIXME: There should be a reserve for root, similar to ext2. - */ -int logfs_statfs(struct dentry *dentry, struct kstatfs *stats) -{ - struct super_block *sb = dentry->d_sb; - struct logfs_super *super = logfs_super(sb); - - stats->f_type = LOGFS_MAGIC_U32; - stats->f_bsize = sb->s_blocksize; - stats->f_blocks = super->s_size >> LOGFS_BLOCK_BITS >> 3; - stats->f_bfree = super->s_free_bytes >> sb->s_blocksize_bits; - stats->f_bavail = super->s_free_bytes >> sb->s_blocksize_bits; - stats->f_files = 0; - stats->f_ffree = 0; - stats->f_namelen = LOGFS_MAX_NAMELEN; - return 0; -} - -static int logfs_sb_set(struct super_block *sb, void *_super) -{ - struct logfs_super *super = _super; - - sb->s_fs_info = super; - sb->s_mtd = super->s_mtd; - sb->s_bdev = super->s_bdev; -#ifdef CONFIG_BLOCK - if (sb->s_bdev) - sb->s_bdi = &bdev_get_queue(sb->s_bdev)->backing_dev_info; -#endif -#ifdef CONFIG_MTD - if (sb->s_mtd) - sb->s_bdi = sb->s_mtd->backing_dev_info; -#endif - return 0; -} - -static int logfs_sb_test(struct super_block *sb, void *_super) -{ - struct logfs_super *super = _super; - struct mtd_info *mtd = super->s_mtd; - - if (mtd && sb->s_mtd == mtd) - return 1; - if (super->s_bdev && sb->s_bdev == super->s_bdev) - return 1; - return 0; -} - -static void set_segment_header(struct logfs_segment_header *sh, u8 type, - u8 level, u32 segno, u32 ec) -{ - sh->pad = 0; - sh->type = type; - sh->level = level; - sh->segno = cpu_to_be32(segno); - sh->ec = cpu_to_be32(ec); - sh->gec = cpu_to_be64(segno); - sh->crc = logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4); -} - -static void logfs_write_ds(struct super_block *sb, struct logfs_disk_super *ds, - u32 segno, u32 ec) -{ - struct logfs_super *super = logfs_super(sb); - struct logfs_segment_header *sh = &ds->ds_sh; - int i; - - memset(ds, 0, sizeof(*ds)); - set_segment_header(sh, SEG_SUPER, 0, segno, ec); - - ds->ds_ifile_levels = super->s_ifile_levels; - ds->ds_iblock_levels = super->s_iblock_levels; - ds->ds_data_levels = super->s_data_levels; /* XXX: Remove */ - ds->ds_segment_shift = super->s_segshift; - ds->ds_block_shift = sb->s_blocksize_bits; - ds->ds_write_shift = super->s_writeshift; - ds->ds_filesystem_size = cpu_to_be64(super->s_size); - ds->ds_segment_size = cpu_to_be32(super->s_segsize); - ds->ds_bad_seg_reserve = cpu_to_be32(super->s_bad_seg_reserve); - ds->ds_feature_incompat = cpu_to_be64(super->s_feature_incompat); - ds->ds_feature_ro_compat= cpu_to_be64(super->s_feature_ro_compat); - ds->ds_feature_compat = cpu_to_be64(super->s_feature_compat); - ds->ds_feature_flags = cpu_to_be64(super->s_feature_flags); - ds->ds_root_reserve = cpu_to_be64(super->s_root_reserve); - ds->ds_speed_reserve = cpu_to_be64(super->s_speed_reserve); - journal_for_each(i) - ds->ds_journal_seg[i] = cpu_to_be32(super->s_journal_seg[i]); - ds->ds_magic = cpu_to_be64(LOGFS_MAGIC); - ds->ds_crc = logfs_crc32(ds, sizeof(*ds), - LOGFS_SEGMENT_HEADERSIZE + 12); -} - -static int write_one_sb(struct super_block *sb, - struct page *(*find_sb)(struct super_block *sb, u64 *ofs)) -{ - struct logfs_super *super = logfs_super(sb); - struct logfs_disk_super *ds; - struct logfs_segment_entry se; - struct page *page; - u64 ofs; - u32 ec, segno; - int err; - - page = find_sb(sb, &ofs); - if (!page) - return -EIO; - ds = page_address(page); - segno = seg_no(sb, ofs); - logfs_get_segment_entry(sb, segno, &se); - ec = be32_to_cpu(se.ec_level) >> 4; - ec++; - logfs_set_segment_erased(sb, segno, ec, 0); - logfs_write_ds(sb, ds, segno, ec); - err = super->s_devops->write_sb(sb, page); - put_page(page); - return err; -} - -int logfs_write_sb(struct super_block *sb) -{ - struct logfs_super *super = logfs_super(sb); - int err; - - /* First superblock */ - err = write_one_sb(sb, super->s_devops->find_first_sb); - if (err) - return err; - - /* Last superblock */ - err = write_one_sb(sb, super->s_devops->find_last_sb); - if (err) - return err; - return 0; -} - -static int ds_cmp(const void *ds0, const void *ds1) -{ - size_t len = sizeof(struct logfs_disk_super); - - /* We know the segment headers differ, so ignore them */ - len -= LOGFS_SEGMENT_HEADERSIZE; - ds0 += LOGFS_SEGMENT_HEADERSIZE; - ds1 += LOGFS_SEGMENT_HEADERSIZE; - return memcmp(ds0, ds1, len); -} - -static int logfs_recover_sb(struct super_block *sb) -{ - struct logfs_super *super = logfs_super(sb); - struct logfs_disk_super _ds0, *ds0 = &_ds0; - struct logfs_disk_super _ds1, *ds1 = &_ds1; - int err, valid0, valid1; - - /* read first superblock */ - err = wbuf_read(sb, super->s_sb_ofs[0], sizeof(*ds0), ds0); - if (err) - return err; - /* read last superblock */ - err = wbuf_read(sb, super->s_sb_ofs[1], sizeof(*ds1), ds1); - if (err) - return err; - valid0 = logfs_check_ds(ds0) == 0; - valid1 = logfs_check_ds(ds1) == 0; - - if (!valid0 && valid1) { - printk(KERN_INFO"First superblock is invalid - fixing.\n"); - return write_one_sb(sb, super->s_devops->find_first_sb); - } - if (valid0 && !valid1) { - printk(KERN_INFO"Last superblock is invalid - fixing.\n"); - return write_one_sb(sb, super->s_devops->find_last_sb); - } - if (valid0 && valid1 && ds_cmp(ds0, ds1)) { - printk(KERN_INFO"Superblocks don't match - fixing.\n"); - return logfs_write_sb(sb); - } - /* If neither is valid now, something's wrong. Didn't we properly - * check them before?!? */ - BUG_ON(!valid0 && !valid1); - return 0; -} - -static int logfs_make_writeable(struct super_block *sb) -{ - int err; - - err = logfs_open_segfile(sb); - if (err) - return err; - - /* Repair any broken superblock copies */ - err = logfs_recover_sb(sb); - if (err) - return err; - - /* Check areas for trailing unaccounted data */ - err = logfs_check_areas(sb); - if (err) - return err; - - /* Do one GC pass before any data gets dirtied */ - logfs_gc_pass(sb); - - /* after all initializations are done, replay the journal - * for rw-mounts, if necessary */ - err = logfs_replay_journal(sb); - if (err) - return err; - - return 0; -} - -static int logfs_get_sb_final(struct super_block *sb) -{ - struct logfs_super *super = logfs_super(sb); - struct inode *rootdir; - int err; - - /* root dir */ - rootdir = logfs_iget(sb, LOGFS_INO_ROOT); - if (IS_ERR(rootdir)) - goto fail; - - sb->s_root = d_make_root(rootdir); - if (!sb->s_root) - goto fail; - - /* at that point we know that ->put_super() will be called */ - super->s_erase_page = alloc_pages(GFP_KERNEL, 0); - if (!super->s_erase_page) - return -ENOMEM; - memset(page_address(super->s_erase_page), 0xFF, PAGE_SIZE); - - /* FIXME: check for read-only mounts */ - err = logfs_make_writeable(sb); - if (err) { - __free_page(super->s_erase_page); - return err; - } - - log_super("LogFS: Finished mounting\n"); - return 0; - -fail: - iput(super->s_master_inode); - iput(super->s_segfile_inode); - iput(super->s_mapping_inode); - return -EIO; -} - -int logfs_check_ds(struct logfs_disk_super *ds) -{ - struct logfs_segment_header *sh = &ds->ds_sh; - - if (ds->ds_magic != cpu_to_be64(LOGFS_MAGIC)) - return -EINVAL; - if (sh->crc != logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4)) - return -EINVAL; - if (ds->ds_crc != logfs_crc32(ds, sizeof(*ds), - LOGFS_SEGMENT_HEADERSIZE + 12)) - return -EINVAL; - return 0; -} - -static struct page *find_super_block(struct super_block *sb) -{ - struct logfs_super *super = logfs_super(sb); - struct page *first, *last; - - first = super->s_devops->find_first_sb(sb, &super->s_sb_ofs[0]); - if (!first || IS_ERR(first)) - return NULL; - last = super->s_devops->find_last_sb(sb, &super->s_sb_ofs[1]); - if (!last || IS_ERR(last)) { - put_page(first); - return NULL; - } - - if (!logfs_check_ds(page_address(first))) { - put_page(last); - return first; - } - - /* First one didn't work, try the second superblock */ - if (!logfs_check_ds(page_address(last))) { - put_page(first); - return last; - } - - /* Neither worked, sorry folks */ - put_page(first); - put_page(last); - return NULL; -} - -static int __logfs_read_sb(struct super_block *sb) -{ - struct logfs_super *super = logfs_super(sb); - struct page *page; - struct logfs_disk_super *ds; - int i; - - page = find_super_block(sb); - if (!page) - return -EINVAL; - - ds = page_address(page); - super->s_size = be64_to_cpu(ds->ds_filesystem_size); - super->s_root_reserve = be64_to_cpu(ds->ds_root_reserve); - super->s_speed_reserve = be64_to_cpu(ds->ds_speed_reserve); - super->s_bad_seg_reserve = be32_to_cpu(ds->ds_bad_seg_reserve); - super->s_segsize = 1 << ds->ds_segment_shift; - super->s_segmask = (1 << ds->ds_segment_shift) - 1; - super->s_segshift = ds->ds_segment_shift; - sb->s_blocksize = 1 << ds->ds_block_shift; - sb->s_blocksize_bits = ds->ds_block_shift; - super->s_writesize = 1 << ds->ds_write_shift; - super->s_writeshift = ds->ds_write_shift; - super->s_no_segs = super->s_size >> super->s_segshift; - super->s_no_blocks = super->s_segsize >> sb->s_blocksize_bits; - super->s_feature_incompat = be64_to_cpu(ds->ds_feature_incompat); - super->s_feature_ro_compat = be64_to_cpu(ds->ds_feature_ro_compat); - super->s_feature_compat = be64_to_cpu(ds->ds_feature_compat); - super->s_feature_flags = be64_to_cpu(ds->ds_feature_flags); - - journal_for_each(i) - super->s_journal_seg[i] = be32_to_cpu(ds->ds_journal_seg[i]); - - super->s_ifile_levels = ds->ds_ifile_levels; - super->s_iblock_levels = ds->ds_iblock_levels; - super->s_data_levels = ds->ds_data_levels; - super->s_total_levels = super->s_ifile_levels + super->s_iblock_levels - + super->s_data_levels; - put_page(page); - return 0; -} - -static int logfs_read_sb(struct super_block *sb, int read_only) -{ - struct logfs_super *super = logfs_super(sb); - int ret; - - super->s_btree_pool = mempool_create(32, btree_alloc, btree_free, NULL); - if (!super->s_btree_pool) - return -ENOMEM; - - btree_init_mempool64(&super->s_shadow_tree.new, super->s_btree_pool); - btree_init_mempool64(&super->s_shadow_tree.old, super->s_btree_pool); - btree_init_mempool32(&super->s_shadow_tree.segment_map, - super->s_btree_pool); - - ret = logfs_init_mapping(sb); - if (ret) - return ret; - - ret = __logfs_read_sb(sb); - if (ret) - return ret; - - if (super->s_feature_incompat & ~LOGFS_FEATURES_INCOMPAT) - return -EIO; - if ((super->s_feature_ro_compat & ~LOGFS_FEATURES_RO_COMPAT) && - !read_only) - return -EIO; - - ret = logfs_init_rw(sb); - if (ret) - return ret; - - ret = logfs_init_areas(sb); - if (ret) - return ret; - - ret = logfs_init_gc(sb); - if (ret) - return ret; - - ret = logfs_init_journal(sb); - if (ret) - return ret; - - return 0; -} - -static void logfs_kill_sb(struct super_block *sb) -{ - struct logfs_super *super = logfs_super(sb); - - log_super("LogFS: Start unmounting\n"); - /* Alias entries slow down mount, so evict as many as possible */ - sync_filesystem(sb); - logfs_write_anchor(sb); - free_areas(sb); - - /* - * From this point on alias entries are simply dropped - and any - * writes to the object store are considered bugs. - */ - log_super("LogFS: Now in shutdown\n"); - generic_shutdown_super(sb); - super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN; - - BUG_ON(super->s_dirty_used_bytes || super->s_dirty_free_bytes); - - logfs_cleanup_gc(sb); - logfs_cleanup_journal(sb); - logfs_cleanup_areas(sb); - logfs_cleanup_rw(sb); - if (super->s_erase_page) - __free_page(super->s_erase_page); - super->s_devops->put_device(super); - logfs_mempool_destroy(super->s_btree_pool); - logfs_mempool_destroy(super->s_alias_pool); - kfree(super); - log_super("LogFS: Finished unmounting\n"); -} - -static struct dentry *logfs_get_sb_device(struct logfs_super *super, - struct file_system_type *type, int flags) -{ - struct super_block *sb; - int err = -ENOMEM; - static int mount_count; - - log_super("LogFS: Start mount %x\n", mount_count++); - - err = -EINVAL; - sb = sget(type, logfs_sb_test, logfs_sb_set, flags | MS_NOATIME, super); - if (IS_ERR(sb)) { - super->s_devops->put_device(super); - kfree(super); - return ERR_CAST(sb); - } - - if (sb->s_root) { - /* Device is already in use */ - super->s_devops->put_device(super); - kfree(super); - return dget(sb->s_root); - } - - /* - * sb->s_maxbytes is limited to 8TB. On 32bit systems, the page cache - * only covers 16TB and the upper 8TB are used for indirect blocks. - * On 64bit system we could bump up the limit, but that would make - * the filesystem incompatible with 32bit systems. - */ - sb->s_maxbytes = (1ull << 43) - 1; - sb->s_max_links = LOGFS_LINK_MAX; - sb->s_op = &logfs_super_operations; - - err = logfs_read_sb(sb, sb->s_flags & MS_RDONLY); - if (err) - goto err1; - - sb->s_flags |= MS_ACTIVE; - err = logfs_get_sb_final(sb); - if (err) { - deactivate_locked_super(sb); - return ERR_PTR(err); - } - return dget(sb->s_root); - -err1: - /* no ->s_root, no ->put_super() */ - iput(super->s_master_inode); - iput(super->s_segfile_inode); - iput(super->s_mapping_inode); - deactivate_locked_super(sb); - return ERR_PTR(err); -} - -static struct dentry *logfs_mount(struct file_system_type *type, int flags, - const char *devname, void *data) -{ - ulong mtdnr; - struct logfs_super *super; - int err; - - super = kzalloc(sizeof(*super), GFP_KERNEL); - if (!super) - return ERR_PTR(-ENOMEM); - - mutex_init(&super->s_dirop_mutex); - mutex_init(&super->s_object_alias_mutex); - INIT_LIST_HEAD(&super->s_freeing_list); - - if (!devname) - err = logfs_get_sb_bdev(super, type, devname); - else if (strncmp(devname, "mtd", 3)) - err = logfs_get_sb_bdev(super, type, devname); - else { - char *garbage; - mtdnr = simple_strtoul(devname+3, &garbage, 0); - if (*garbage) - err = -EINVAL; - else - err = logfs_get_sb_mtd(super, mtdnr); - } - - if (err) { - kfree(super); - return ERR_PTR(err); - } - - return logfs_get_sb_device(super, type, flags); -} - -static struct file_system_type logfs_fs_type = { - .owner = THIS_MODULE, - .name = "logfs", - .mount = logfs_mount, - .kill_sb = logfs_kill_sb, - .fs_flags = FS_REQUIRES_DEV, - -}; -MODULE_ALIAS_FS("logfs"); - -static int __init logfs_init(void) -{ - int ret; - - emergency_page = alloc_pages(GFP_KERNEL, 0); - if (!emergency_page) - return -ENOMEM; - - ret = logfs_compr_init(); - if (ret) - goto out1; - - ret = logfs_init_inode_cache(); - if (ret) - goto out2; - - ret = register_filesystem(&logfs_fs_type); - if (!ret) - return 0; - logfs_destroy_inode_cache(); -out2: - logfs_compr_exit(); -out1: - __free_pages(emergency_page, 0); - return ret; -} - -static void __exit logfs_exit(void) -{ - unregister_filesystem(&logfs_fs_type); - logfs_destroy_inode_cache(); - logfs_compr_exit(); - __free_pages(emergency_page, 0); -} - -module_init(logfs_init); -module_exit(logfs_exit); - -MODULE_LICENSE("GPL v2"); -MODULE_AUTHOR("Joern Engel <joern@logfs.org>"); -MODULE_DESCRIPTION("scalable flash filesystem"); |