diff options
Diffstat (limited to 'fs/nilfs2')
| -rw-r--r-- | fs/nilfs2/super.c | 1366 |
1 files changed, 1366 insertions, 0 deletions
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c new file mode 100644 index 00000000000..10e82c00aed --- /dev/null +++ b/fs/nilfs2/super.c @@ -0,0 +1,1366 @@ +/* + * super.c - NILFS module and super block management. + * + * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * Written by Ryusuke Konishi <ryusuke@osrg.net> + */ +/* + * linux/fs/ext2/super.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 + * + * Big-endian to little-endian byte-swapping/bitmaps by + * David S. Miller (davem@caip.rutgers.edu), 1995 + */ + +#include <linux/module.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/blkdev.h> +#include <linux/parser.h> +#include <linux/random.h> +#include <linux/crc32.h> +#include <linux/smp_lock.h> +#include <linux/vfs.h> +#include <linux/writeback.h> +#include <linux/kobject.h> +#include <linux/exportfs.h> +#include "nilfs.h" +#include "mdt.h" +#include "alloc.h" +#include "page.h" +#include "cpfile.h" +#include "ifile.h" +#include "dat.h" +#include "segment.h" +#include "segbuf.h" + +MODULE_AUTHOR("NTT Corp."); +MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem " + "(NILFS)"); +MODULE_VERSION(NILFS_VERSION); +MODULE_LICENSE("GPL"); + +static int nilfs_remount(struct super_block *sb, int *flags, char *data); +static int test_exclusive_mount(struct file_system_type *fs_type, + struct block_device *bdev, int flags); + +/** + * nilfs_error() - report failure condition on a filesystem + * + * nilfs_error() sets an ERROR_FS flag on the superblock as well as + * reporting an error message. It should be called when NILFS detects + * incoherences or defects of meta data on disk. As for sustainable + * errors such as a single-shot I/O error, nilfs_warning() or the printk() + * function should be used instead. + * + * The segment constructor must not call this function because it can + * kill itself. + */ +void nilfs_error(struct super_block *sb, const char *function, + const char *fmt, ...) +{ + struct nilfs_sb_info *sbi = NILFS_SB(sb); + va_list args; + + va_start(args, fmt); + printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function); + vprintk(fmt, args); + printk("\n"); + va_end(args); + + if (!(sb->s_flags & MS_RDONLY)) { + struct the_nilfs *nilfs = sbi->s_nilfs; + + if (!nilfs_test_opt(sbi, ERRORS_CONT)) + nilfs_detach_segment_constructor(sbi); + + down_write(&nilfs->ns_sem); + if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) { + nilfs->ns_mount_state |= NILFS_ERROR_FS; + nilfs->ns_sbp->s_state |= cpu_to_le16(NILFS_ERROR_FS); + nilfs_commit_super(sbi); + } + up_write(&nilfs->ns_sem); + + if (nilfs_test_opt(sbi, ERRORS_RO)) { + printk(KERN_CRIT "Remounting filesystem read-only\n"); + sb->s_flags |= MS_RDONLY; + } + } + + if (nilfs_test_opt(sbi, ERRORS_PANIC)) + panic("NILFS (device %s): panic forced after error\n", + sb->s_id); +} + +void nilfs_warning(struct super_block *sb, const char *function, + const char *fmt, ...) +{ + va_list args; + + va_start(args, fmt); + printk(KERN_WARNING "NILFS warning (device %s): %s: ", + sb->s_id, function); + vprintk(fmt, args); + printk("\n"); + va_end(args); +} + +static struct kmem_cache *nilfs_inode_cachep; + +struct inode *nilfs_alloc_inode(struct super_block *sb) +{ + struct nilfs_inode_info *ii; + + ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS); + if (!ii) + return NULL; + ii->i_bh = NULL; + ii->i_state = 0; + ii->vfs_inode.i_version = 1; + nilfs_btnode_cache_init(&ii->i_btnode_cache); + return &ii->vfs_inode; +} + +void nilfs_destroy_inode(struct inode *inode) +{ + kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode)); +} + +static void init_once(void *obj) +{ + struct nilfs_inode_info *ii = obj; + + INIT_LIST_HEAD(&ii->i_dirty); +#ifdef CONFIG_NILFS_XATTR + init_rwsem(&ii->xattr_sem); +#endif + nilfs_btnode_cache_init_once(&ii->i_btnode_cache); + ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union; + inode_init_once(&ii->vfs_inode); +} + +static int nilfs_init_inode_cache(void) +{ + nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache", + sizeof(struct nilfs_inode_info), + 0, SLAB_RECLAIM_ACCOUNT, + init_once); + + return (nilfs_inode_cachep == NULL) ? -ENOMEM : 0; +} + +static inline void nilfs_destroy_inode_cache(void) +{ + kmem_cache_destroy(nilfs_inode_cachep); +} + +static void nilfs_clear_inode(struct inode *inode) +{ + struct nilfs_inode_info *ii = NILFS_I(inode); + struct nilfs_transaction_info ti; + struct nilfs_sb_info *sbi = NILFS_SB(inode->i_sb); + +#ifdef CONFIG_NILFS_POSIX_ACL + if (ii->i_acl && ii->i_acl != NILFS_ACL_NOT_CACHED) { + posix_acl_release(ii->i_acl); + ii->i_acl = NILFS_ACL_NOT_CACHED; + } + if (ii->i_default_acl && ii->i_default_acl != NILFS_ACL_NOT_CACHED) { + posix_acl_release(ii->i_default_acl); + ii->i_default_acl = NILFS_ACL_NOT_CACHED; + } +#endif + /* + * Free resources allocated in nilfs_read_inode(), here. + */ + nilfs_transaction_begin(inode->i_sb, &ti, 0); + + spin_lock(&sbi->s_inode_lock); + if (!list_empty(&ii->i_dirty)) + list_del_init(&ii->i_dirty); + brelse(ii->i_bh); + ii->i_bh = NULL; + spin_unlock(&sbi->s_inode_lock); + + if (test_bit(NILFS_I_BMAP, &ii->i_state)) + nilfs_bmap_clear(ii->i_bmap); + + nilfs_btnode_cache_clear(&ii->i_btnode_cache); + + nilfs_transaction_end(inode->i_sb, 0); +} + +/** + * nilfs_update_last_segment - change pointer to the latest segment + * @sbi: nilfs_sb_info + * @update_cno: flag whether to update checkpoint number. + * + * nilfs_update_last_segment() changes information in the super block + * after a partial segment is written out successfully. The super + * block is marked dirty. It will be written out at the next VFS sync + * operations such as sync_supers() and generic_shutdown_super(). + */ +void nilfs_update_last_segment(struct nilfs_sb_info *sbi, int update_cno) +{ + struct the_nilfs *nilfs = sbi->s_nilfs; + struct nilfs_super_block *sbp = nilfs->ns_sbp; + + /* nilfs->sem must be locked by the caller. */ + spin_lock(&nilfs->ns_last_segment_lock); + if (update_cno) + nilfs->ns_last_cno = nilfs->ns_cno++; + sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq); + sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg); + sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno); + spin_unlock(&nilfs->ns_last_segment_lock); + + sbi->s_super->s_dirt = 1; /* must be set if delaying the call of + nilfs_commit_super() */ +} + +static int nilfs_sync_super(struct nilfs_sb_info *sbi) +{ + struct the_nilfs *nilfs = sbi->s_nilfs; + int err; + int barrier_done = 0; + + if (nilfs_test_opt(sbi, BARRIER)) { + set_buffer_ordered(nilfs->ns_sbh); + barrier_done = 1; + } + retry: + set_buffer_dirty(nilfs->ns_sbh); + err = sync_dirty_buffer(nilfs->ns_sbh); + if (err == -EOPNOTSUPP && barrier_done) { + nilfs_warning(sbi->s_super, __func__, + "barrier-based sync failed. " + "disabling barriers\n"); + nilfs_clear_opt(sbi, BARRIER); + barrier_done = 0; + clear_buffer_ordered(nilfs->ns_sbh); + goto retry; + } + if (unlikely(err)) + printk(KERN_ERR + "NILFS: unable to write superblock (err=%d)\n", err); + else { + nilfs_dispose_used_segments(nilfs); + clear_nilfs_discontinued(nilfs); + } + + return err; +} + +int nilfs_commit_super(struct nilfs_sb_info *sbi) +{ + struct the_nilfs *nilfs = sbi->s_nilfs; + struct nilfs_super_block *sbp = nilfs->ns_sbp; + sector_t nfreeblocks; + int err; + + /* nilfs->sem must be locked by the caller. */ + err = nilfs_count_free_blocks(nilfs, &nfreeblocks); + if (unlikely(err)) { + printk(KERN_ERR "NILFS: failed to count free blocks\n"); + return err; + } + sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks); + sbp->s_wtime = cpu_to_le64(get_seconds()); + sbp->s_sum = 0; + sbp->s_sum = crc32_le(nilfs->ns_crc_seed, (unsigned char *)sbp, + le16_to_cpu(sbp->s_bytes)); + + sbi->s_super->s_dirt = 0; + return nilfs_sync_super(sbi); +} + +static void nilfs_put_super(struct super_block *sb) +{ + struct nilfs_sb_info *sbi = NILFS_SB(sb); + struct the_nilfs *nilfs = sbi->s_nilfs; + + nilfs_detach_segment_constructor(sbi); + + if (!(sb->s_flags & MS_RDONLY)) { + down_write(&nilfs->ns_sem); + nilfs->ns_sbp->s_state = cpu_to_le16(nilfs->ns_mount_state); + nilfs_commit_super(sbi); + up_write(&nilfs->ns_sem); + } + + nilfs_detach_checkpoint(sbi); + put_nilfs(sbi->s_nilfs); + sbi->s_super = NULL; + sb->s_fs_info = NULL; + kfree(sbi); +} + +/** + * nilfs_write_super - write super block(s) of NILFS + * @sb: super_block + * + * nilfs_write_super() gets a fs-dependent lock, writes super block(s), and + * clears s_dirt. This function is called in the section protected by + * lock_super(). + * + * The s_dirt flag is managed by each filesystem and we protect it by ns_sem + * of the struct the_nilfs. Lock order must be as follows: + * + * 1. lock_super() + * 2. down_write(&nilfs->ns_sem) + * + * Inside NILFS, locking ns_sem is enough to protect s_dirt and the buffer + * of the super block (nilfs->ns_sbp). + * + * In most cases, VFS functions call lock_super() before calling these + * methods. So we must be careful not to bring on deadlocks when using + * lock_super(); see generic_shutdown_super(), write_super(), and so on. + * + * Note that order of lock_kernel() and lock_super() depends on contexts + * of VFS. We should also note that lock_kernel() can be used in its + * protective section and only the outermost one has an effect. + */ +static void nilfs_write_super(struct super_block *sb) +{ + struct nilfs_sb_info *sbi = NILFS_SB(sb); + struct the_nilfs *nilfs = sbi->s_nilfs; + + down_write(&nilfs->ns_sem); + if (!(sb->s_flags & MS_RDONLY)) + nilfs_commit_super(sbi); + sb->s_dirt = 0; + up_write(&nilfs->ns_sem); +} + +static int nilfs_sync_fs(struct super_block *sb, int wait) +{ + int err = 0; + + /* This function is called when super block should be written back */ + if (wait) + err = nilfs_construct_segment(sb); + return err; +} + +int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno) +{ + struct the_nilfs *nilfs = sbi->s_nilfs; + struct nilfs_checkpoint *raw_cp; + struct buffer_head *bh_cp; + int err; + + down_write(&nilfs->ns_sem); + list_add(&sbi->s_list, &nilfs->ns_supers); + up_write(&nilfs->ns_sem); + + sbi->s_ifile = nilfs_mdt_new( + nilfs, sbi->s_super, NILFS_IFILE_INO, NILFS_IFILE_GFP); + if (!sbi->s_ifile) + return -ENOMEM; + + err = nilfs_palloc_init_blockgroup(sbi->s_ifile, nilfs->ns_inode_size); + if (unlikely(err)) + goto failed; + + err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, + &bh_cp); + if (unlikely(err)) { + if (err == -ENOENT || err == -EINVAL) { + printk(KERN_ERR + "NILFS: Invalid checkpoint " + "(checkpoint number=%llu)\n", + (unsigned long long)cno); + err = -EINVAL; + } + goto failed; + } + err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode); + if (unlikely(err)) + goto failed_bh; + atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count)); + atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count)); + + nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); + return 0; + + failed_bh: + nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); + failed: + nilfs_mdt_destroy(sbi->s_ifile); + sbi->s_ifile = NULL; + + down_write(&nilfs->ns_sem); + list_del_init(&sbi->s_list); + up_write(&nilfs->ns_sem); + + return err; +} + +void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi) +{ + struct the_nilfs *nilfs = sbi->s_nilfs; + + nilfs_mdt_clear(sbi->s_ifile); + nilfs_mdt_destroy(sbi->s_ifile); + sbi->s_ifile = NULL; + down_write(&nilfs->ns_sem); + list_del_init(&sbi->s_list); + up_write(&nilfs->ns_sem); +} + +static int nilfs_mark_recovery_complete(struct nilfs_sb_info *sbi) +{ + struct the_nilfs *nilfs = sbi->s_nilfs; + int err = 0; + + down_write(&nilfs->ns_sem); + if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) { + nilfs->ns_mount_state |= NILFS_VALID_FS; + err = nilfs_commit_super(sbi); + if (likely(!err)) + printk(KERN_INFO "NILFS: recovery complete.\n"); + } + up_write(&nilfs->ns_sem); + return err; +} + +static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) +{ + struct super_block *sb = dentry->d_sb; + struct nilfs_sb_info *sbi = NILFS_SB(sb); + unsigned long long blocks; + unsigned long overhead; + unsigned long nrsvblocks; + sector_t nfreeblocks; + struct the_nilfs *nilfs = sbi->s_nilfs; + int err; + + /* + * Compute all of the segment blocks + * + * The blocks before first segment and after last segment + * are excluded. + */ + blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments + - nilfs->ns_first_data_block; + nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment; + + /* + * Compute the overhead + * + * When distributing meta data blocks outside semgent structure, + * We must count them as the overhead. + */ + overhead = 0; + + err = nilfs_count_free_blocks(nilfs, &nfreeblocks); + if (unlikely(err)) + return err; + + buf->f_type = NILFS_SUPER_MAGIC; + buf->f_bsize = sb->s_blocksize; + buf->f_blocks = blocks - overhead; + buf->f_bfree = nfreeblocks; + buf->f_bavail = (buf->f_bfree >= nrsvblocks) ? + (buf->f_bfree - nrsvblocks) : 0; + buf->f_files = atomic_read(&sbi->s_inodes_count); + buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */ + buf->f_namelen = NILFS_NAME_LEN; + return 0; +} + +static struct super_operations nilfs_sops = { + .alloc_inode = nilfs_alloc_inode, + .destroy_inode = nilfs_destroy_inode, + .dirty_inode = nilfs_dirty_inode, + /* .write_inode = nilfs_write_inode, */ + /* .put_inode = nilfs_put_inode, */ + /* .drop_inode = nilfs_drop_inode, */ + .delete_inode = nilfs_delete_inode, + .put_super = nilfs_put_super, + .write_super = nilfs_write_super, + .sync_fs = nilfs_sync_fs, + /* .write_super_lockfs */ + /* .unlockfs */ + .statfs = nilfs_statfs, + .remount_fs = nilfs_remount, + .clear_inode = nilfs_clear_inode, + /* .umount_begin */ + /* .show_options */ +}; + +static struct inode * +nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation) +{ + struct inode *inode; + + if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO && + ino != NILFS_SKETCH_INO) + return ERR_PTR(-ESTALE); + + inode = nilfs_iget(sb, ino); + if (IS_ERR(inode)) + return ERR_CAST(inode); + if (generation && inode->i_generation != generation) { + iput(inode); + return ERR_PTR(-ESTALE); + } + + return inode; +} + +static struct dentry * +nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, + int fh_type) +{ + return generic_fh_to_dentry(sb, fid, fh_len, fh_type, + nilfs_nfs_get_inode); +} + +static struct dentry * +nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, + int fh_type) +{ + return generic_fh_to_parent(sb, fid, fh_len, fh_type, + nilfs_nfs_get_inode); +} + +static struct export_operations nilfs_export_ops = { + .fh_to_dentry = nilfs_fh_to_dentry, + .fh_to_parent = nilfs_fh_to_parent, + .get_parent = nilfs_get_parent, +}; + +enum { + Opt_err_cont, Opt_err_panic, Opt_err_ro, + Opt_barrier, Opt_snapshot, Opt_order, + Opt_err, +}; + +static match_table_t tokens = { + {Opt_err_cont, "errors=continue"}, + {Opt_err_panic, "errors=panic"}, + {Opt_err_ro, "errors=remount-ro"}, + {Opt_barrier, "barrier=%s"}, + {Opt_snapshot, "cp=%u"}, + {Opt_order, "order=%s"}, + {Opt_err, NULL} +}; + +static int match_bool(substring_t *s, int *result) +{ + int len = s->to - s->from; + + if (strncmp(s->from, "on", len) == 0) + *result = 1; + else if (strncmp(s->from, "off", len) == 0) + *result = 0; + else + return 1; + return 0; +} + +static int parse_options(char *options, struct super_block *sb) +{ + struct nilfs_sb_info *sbi = NILFS_SB(sb); + char *p; + substring_t args[MAX_OPT_ARGS]; + int option; + + if (!options) + return 1; + + while ((p = strsep(&options, ",")) != NULL) { + int token; + if (!*p) + continue; + + token = match_token(p, tokens, args); + switch (token) { + case Opt_barrier: + if (match_bool(&args[0], &option)) + return 0; + if (option) + nilfs_set_opt(sbi, BARRIER); + else + nilfs_clear_opt(sbi, BARRIER); + break; + case Opt_order: + if (strcmp(args[0].from, "relaxed") == 0) + /* Ordered data semantics */ + nilfs_clear_opt(sbi, STRICT_ORDER); + else if (strcmp(args[0].from, "strict") == 0) + /* Strict in-order semantics */ + nilfs_set_opt(sbi, STRICT_ORDER); + else + return 0; + break; + case Opt_err_panic: + nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC); + break; + case Opt_err_ro: + nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO); + break; + case Opt_err_cont: + nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT); + break; + case Opt_snapshot: + if (match_int(&args[0], &option) || option <= 0) + return 0; + if (!(sb->s_flags & MS_RDONLY)) + return 0; + sbi->s_snapshot_cno = option; + nilfs_set_opt(sbi, SNAPSHOT); + break; + default: + printk(KERN_ERR + "NILFS: Unrecognized mount option \"%s\"\n", p); + return 0; + } + } + return 1; +} + +static inline void +nilfs_set_default_options(struct nilfs_sb_info *sbi, + struct nilfs_super_block *sbp) +{ + sbi->s_mount_opt = + NILFS_MOUNT_ERRORS_CONT | NILFS_MOUNT_BARRIER; +} + +static int nilfs_setup_super(struct nilfs_sb_info *sbi) +{ + struct the_nilfs *nilfs = sbi->s_nilfs; + struct nilfs_super_block *sbp = nilfs->ns_sbp; + int max_mnt_count = le16_to_cpu(sbp->s_max_mnt_count); + int mnt_count = le16_to_cpu(sbp->s_mnt_count); + + /* nilfs->sem must be locked by the caller. */ + if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) { + printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n"); + } else if (nilfs->ns_mount_state & NILFS_ERROR_FS) { + printk(KERN_WARNING + "NILFS warning: mounting fs with errors\n"); +#if 0 + } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) { + printk(KERN_WARNING + "NILFS warning: maximal mount count reached\n"); +#endif + } + if (!max_mnt_count) + sbp->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT); + + sbp->s_mnt_count = cpu_to_le16(mnt_count + 1); + sbp->s_state = cpu_to_le16(le16_to_cpu(sbp->s_state) & ~NILFS_VALID_FS); + sbp->s_mtime = cpu_to_le64(get_seconds()); + return nilfs_commit_super(sbi); +} + +struct nilfs_super_block * +nilfs_load_super_block(struct super_block *sb, struct buffer_head **pbh) +{ + int blocksize; + unsigned long offset, sb_index; + + /* + * Adjusting block size + * Blocksize will be enlarged when it is smaller than hardware + * sector size. + * Disk format of superblock does not change. + */ + blocksize = sb_min_blocksize(sb, BLOCK_SIZE); + if (!blocksize) { + printk(KERN_ERR + "NILFS: unable to set blocksize of superblock\n"); + return NULL; + } + sb_index = NILFS_SB_OFFSET_BYTES / blocksize; + offset = NILFS_SB_OFFSET_BYTES % blocksize; + + *pbh = sb_bread(sb, sb_index); + if (!*pbh) { + printk(KERN_ERR "NILFS: unable to read superblock\n"); + return NULL; + } + return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); +} + +struct nilfs_super_block * +nilfs_reload_super_block(struct super_block *sb, struct buffer_head **pbh, + int blocksize) +{ + struct nilfs_super_block *sbp; + unsigned long offset, sb_index; + int hw_blocksize = bdev_hardsect_size(sb->s_bdev); + + if (blocksize < hw_blocksize) { + printk(KERN_ERR + "NILFS: blocksize %d too small for device " + "(sector-size = %d).\n", + blocksize, hw_blocksize); + goto failed_sbh; + } + brelse(*pbh); + sb_set_blocksize(sb, blocksize); + + sb_index = NILFS_SB_OFFSET_BYTES / blocksize; + offset = NILFS_SB_OFFSET_BYTES % blocksize; + + *pbh = sb_bread(sb, sb_index); + if (!*pbh) { + printk(KERN_ERR + "NILFS: cannot read superblock on 2nd try.\n"); + goto failed; + } + + sbp = (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); + if (sbp->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { + printk(KERN_ERR + "NILFS: !? Magic mismatch on 2nd try.\n"); + goto failed_sbh; + } + return sbp; + + failed_sbh: + brelse(*pbh); + + failed: + return NULL; +} + +int nilfs_store_magic_and_option(struct super_block *sb, + struct nilfs_super_block *sbp, + char *data) +{ + struct nilfs_sb_info *sbi = NILFS_SB(sb); + + /* trying to fill super (1st stage) */ + sb->s_magic = le16_to_cpu(sbp->s_magic); + + /* FS independent flags */ +#ifdef NILFS_ATIME_DISABLE + sb->s_flags |= MS_NOATIME; +#endif + + if (sb->s_magic != NILFS_SUPER_MAGIC) { + printk("NILFS: Can't find nilfs on dev %s.\n", sb->s_id); + return -EINVAL; + } + + nilfs_set_default_options(sbi, sbp); + + sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid); + sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid); + sbi->s_interval = le32_to_cpu(sbp->s_c_interval); + sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max); + + if (!parse_options(data, sb)) + return -EINVAL; + + return 0; +} + +/** + * nilfs_fill_super() - initialize a super block instance + * @sb: super_block + * @data: mount options + * @silent: silent mode flag + * @nilfs: the_nilfs struct + * + * This function is called exclusively by bd_mount_mutex. + * So, the recovery process is protected from other simultaneous mounts. + */ +static int +nilfs_fill_super(struct super_block *sb, void *data, int silent, + struct the_nilfs *nilfs) +{ + struct nilfs_sb_info *sbi; + struct inode *root; + __u64 cno; + int err; + + sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); + if (!sbi) + return -ENOMEM; + + sb->s_fs_info = sbi; + + get_nilfs(nilfs); + sbi->s_nilfs = nilfs; + sbi->s_super = sb; + + err = init_nilfs(nilfs, sbi, (char *)data); + if (err) + goto failed_sbi; + + spin_lock_init(&sbi->s_inode_lock); + INIT_LIST_HEAD(&sbi->s_dirty_files); + INIT_LIST_HEAD(&sbi->s_list); + + /* + * Following initialization is overlapped because + * nilfs_sb_info structure has been cleared at the beginning. + * But we reserve them to keep our interest and make ready + * for the future change. + */ + get_random_bytes(&sbi->s_next_generation, + sizeof(sbi->s_next_generation)); + spin_lock_init(&sbi->s_next_gen_lock); + + sb->s_op = &nilfs_sops; + sb->s_export_op = &nilfs_export_ops; + sb->s_root = NULL; + + if (!nilfs_loaded(nilfs)) { + err = load_nilfs(nilfs, sbi); + if (err) + goto failed_sbi; + } + cno = nilfs_last_cno(nilfs); + + if (sb->s_flags & MS_RDONLY) { + if (nilfs_test_opt(sbi, SNAPSHOT)) { + if (!nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, + sbi->s_snapshot_cno)) { + printk(KERN_ERR + "NILFS: The specified checkpoint is " + "not a snapshot " + "(checkpoint number=%llu).\n", + (unsigned long long)sbi->s_snapshot_cno); + err = -EINVAL; + goto failed_sbi; + } + cno = sbi->s_snapshot_cno; + } else + /* Read-only mount */ + sbi->s_snapshot_cno = cno; + } + + err = nilfs_attach_checkpoint(sbi, cno); + if (err) { + printk(KERN_ERR "NILFS: error loading a checkpoint" + " (checkpoint number=%llu).\n", (unsigned long long)cno); + goto failed_sbi; + } + + if (!(sb->s_flags & MS_RDONLY)) { + err = nilfs_attach_segment_constructor(sbi, NULL); + if (err) + goto failed_checkpoint; + } + + root = nilfs_iget(sb, NILFS_ROOT_INO); + if (IS_ERR(root)) { + printk(KERN_ERR "NILFS: get root inode failed\n"); + err = PTR_ERR(root); + goto failed_segctor; + } + if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { + iput(root); + printk(KERN_ERR "NILFS: corrupt root inode.\n"); + err = -EINVAL; + goto failed_segctor; + } + sb->s_root = d_alloc_root(root); + if (!sb->s_root) { + iput(root); + printk(KERN_ERR "NILFS: get root dentry failed\n"); + err = -ENOMEM; + goto failed_segctor; + } + + if (!(sb->s_flags & MS_RDONLY)) { + down_write(&nilfs->ns_sem); + nilfs_setup_super(sbi); + up_write(&nilfs->ns_sem); + } + + err = nilfs_mark_recovery_complete(sbi); + if (unlikely(err)) { + printk(KERN_ERR "NILFS: recovery failed.\n"); + goto failed_root; + } + + return 0; + + failed_root: + dput(sb->s_root); + sb->s_root = NULL; + + failed_segctor: + nilfs_detach_segment_constructor(sbi); + + failed_checkpoint: + nilfs_detach_checkpoint(sbi); + + failed_sbi: + put_nilfs(nilfs); + sb->s_fs_info = NULL; + kfree(sbi); + return err; +} + +static int nilfs_remount(struct super_block *sb, int *flags, char *data) +{ + struct nilfs_sb_info *sbi = NILFS_SB(sb); + struct nilfs_super_block *sbp; + struct the_nilfs *nilfs = sbi->s_nilfs; + unsigned long old_sb_flags; + struct nilfs_mount_options old_opts; + int err; + + old_sb_flags = sb->s_flags; + old_opts.mount_opt = sbi->s_mount_opt; + old_opts.snapshot_cno = sbi->s_snapshot_cno; + + if (!parse_options(data, sb)) { + err = -EINVAL; + goto restore_opts; + } + sb->s_flags = (sb->s_flags & ~MS_POSIXACL); + + if ((*flags & MS_RDONLY) && + sbi->s_snapshot_cno != old_opts.snapshot_cno) { + printk(KERN_WARNING "NILFS (device %s): couldn't " + "remount to a different snapshot. \n", + sb->s_id); + err = -EINVAL; + goto restore_opts; + } + + if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) + goto out; + if (*flags & MS_RDONLY) { + /* Shutting down the segment constructor */ + nilfs_detach_segment_constructor(sbi); + sb->s_flags |= MS_RDONLY; + + sbi->s_snapshot_cno = nilfs_last_cno(nilfs); + /* nilfs_set_opt(sbi, SNAPSHOT); */ + + /* + * Remounting a valid RW partition RDONLY, so set + * the RDONLY flag and then mark the partition as valid again. + */ + down_write(&nilfs->ns_sem); + sbp = nilfs->ns_sbp; + if (!(sbp->s_state & le16_to_cpu(NILFS_VALID_FS)) && + (nilfs->ns_mount_state & NILFS_VALID_FS)) + sbp->s_state = cpu_to_le16(nilfs->ns_mount_state); + sbp->s_mtime = cpu_to_le64(get_seconds()); + nilfs_commit_super(sbi); + up_write(&nilfs->ns_sem); + } else { + /* + * Mounting a RDONLY partition read-write, so reread and + * store the current valid flag. (It may have been changed + * by fsck since we originally mounted the partition.) + */ + down(&sb->s_bdev->bd_mount_sem); + /* Check existing RW-mount */ + if (test_exclusive_mount(sb->s_type, sb->s_bdev, 0)) { + printk(KERN_WARNING "NILFS (device %s): couldn't " + "remount because a RW-mount exists.\n", + sb->s_id); + err = -EBUSY; + goto rw_remount_failed; + } + if (sbi->s_snapshot_cno != nilfs_last_cno(nilfs)) { + printk(KERN_WARNING "NILFS (device %s): couldn't " + "remount because the current RO-mount is not " + "the latest one.\n", + sb->s_id); + err = -EINVAL; + goto rw_remount_failed; + } + sb->s_flags &= ~MS_RDONLY; + nilfs_clear_opt(sbi, SNAPSHOT); + sbi->s_snapshot_cno = 0; + + err = nilfs_attach_segment_constructor(sbi, NULL); + if (err) + goto rw_remount_failed; + + down_write(&nilfs->ns_sem); + nilfs_setup_super(sbi); + up_write(&nilfs->ns_sem); + + up(&sb->s_bdev->bd_mount_sem); + } + out: + return 0; + + rw_remount_failed: + up(&sb->s_bdev->bd_mount_sem); + restore_opts: + sb->s_flags = old_sb_flags; + sbi->s_mount_opt = old_opts.mount_opt; + sbi->s_snapshot_cno = old_opts.snapshot_cno; + return err; +} + +struct nilfs_super_data { + struct block_device *bdev; + __u64 cno; + int flags; +}; + +/** + * nilfs_identify - pre-read mount options needed to identify mount instance + * @data: mount options + * @sd: nilfs_super_data + */ +static int nilfs_identify(char *data, struct nilfs_super_data *sd) +{ + char *p, *options = data; + substring_t args[MAX_OPT_ARGS]; + int option, token; + int ret = 0; + + do { + p = strsep(&options, ","); + if (p != NULL && *p) { + token = match_token(p, tokens, args); + if (token == Opt_snapshot) { + if (!(sd->flags & MS_RDONLY)) + ret++; + else { + ret = match_int(&args[0], &option); + if (!ret) { + if (option > 0) + sd->cno = option; + else + ret++; + } + } + } + if (ret) + printk(KERN_ERR + "NILFS: invalid mount option: %s\n", p); + } + if (!options) + break; + BUG_ON(options == data); + *(options - 1) = ','; + } while (!ret); + return ret; +} + +static int nilfs_set_bdev_super(struct super_block *s, void *data) +{ + struct nilfs_super_data *sd = data; + + s->s_bdev = sd->bdev; + s->s_dev = s->s_bdev->bd_dev; + return 0; +} + +static int nilfs_test_bdev_super(struct super_block *s, void *data) +{ + struct nilfs_super_data *sd = data; + + return s->s_bdev == sd->bdev; +} + +static int nilfs_test_bdev_super2(struct super_block *s, void *data) +{ + struct nilfs_super_data *sd = data; + int ret; + + if (s->s_bdev != sd->bdev) + return 0; + + if (!((s->s_flags | sd->flags) & MS_RDONLY)) + return 1; /* Reuse an old R/W-mode super_block */ + + if (s->s_flags & sd->flags & MS_RDONLY) { + if (down_read_trylock(&s->s_umount)) { + ret = s->s_root && + (sd->cno == NILFS_SB(s)->s_snapshot_cno); + up_read(&s->s_umount); + /* + * This path is locked with sb_lock by sget(). + * So, drop_super() causes deadlock. + */ + return ret; + } + } + return 0; +} + +static int +nilfs_get_sb(struct file_system_type *fs_type, int flags, + const char *dev_name, void *data, struct vfsmount *mnt) +{ + struct nilfs_super_data sd; + struct super_block *s, *s2; + struct the_nilfs *nilfs = NULL; + int err, need_to_close = 1; + + sd.bdev = open_bdev_exclusive(dev_name, flags, fs_type); + if (IS_ERR(sd.bdev)) + return PTR_ERR(sd.bdev); + + /* + * To get mount instance using sget() vfs-routine, NILFS needs + * much more information than normal filesystems to identify mount + * instance. For snapshot mounts, not only a mount type (ro-mount + * or rw-mount) but also a checkpoint number is required. + * The results are passed in sget() using nilfs_super_data. + */ + sd.cno = 0; + sd.flags = flags; + if (nilfs_identify((char *)data, &sd)) { + err = -EINVAL; + goto failed; + } + + /* + * once the super is inserted into the list by sget, s_umount + * will protect the lockfs code from trying to start a snapshot + * while we are mounting + */ + down(&sd.bdev->bd_mount_sem); + if (!sd.cno && + (err = test_exclusive_mount(fs_type, sd.bdev, flags ^ MS_RDONLY))) { + err = (err < 0) ? : -EBUSY; + goto failed_unlock; + } + + /* + * Phase-1: search any existent instance and get the_nilfs + */ + s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd); + if (IS_ERR(s)) + goto error_s; + + if (!s->s_root) { + err = -ENOMEM; + nilfs = alloc_nilfs(sd.bdev); + if (!nilfs) + goto cancel_new; + } else { + struct nilfs_sb_info *sbi = NILFS_SB(s); + + BUG_ON(!sbi || !sbi->s_nilfs); + /* + * s_umount protects super_block from unmount process; + * It covers pointers of nilfs_sb_info and the_nilfs. + */ + nilfs = sbi->s_nilfs; + get_nilfs(nilfs); + up_write(&s->s_umount); + + /* + * Phase-2: search specified snapshot or R/W mode super_block + */ + if (!sd.cno) + /* trying to get the latest checkpoint. */ + sd.cno = nilfs_last_cno(nilfs); + + s2 = sget(fs_type, nilfs_test_bdev_super2, + nilfs_set_bdev_super, &sd); + deactivate_super(s); + /* + * Although deactivate_super() invokes close_bdev_exclusive() at + * kill_block_super(). Here, s is an existent mount; we need + * one more close_bdev_exclusive() call. + */ + s = s2; + if (IS_ERR(s)) + goto error_s; + } + + if (!s->s_root) { + char b[BDEVNAME_SIZE]; + + s->s_flags = flags; + strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id)); + sb_set_blocksize(s, block_size(sd.bdev)); + + err = nilfs_fill_super(s, data, flags & MS_VERBOSE, nilfs); + if (err) + goto cancel_new; + + s->s_flags |= MS_ACTIVE; + need_to_close = 0; + } else if (!(s->s_flags & MS_RDONLY)) { + err = -EBUSY; + } + + up(&sd.bdev->bd_mount_sem); + put_nilfs(nilfs); + if (need_to_close) + close_bdev_exclusive(sd.bdev, flags); + simple_set_mnt(mnt, s); + return 0; + + error_s: + up(&sd.bdev->bd_mount_sem); + if (nilfs) + put_nilfs(nilfs); + close_bdev_exclusive(sd.bdev, flags); + return PTR_ERR(s); + + failed_unlock: + up(&sd.bdev->bd_mount_sem); + failed: + close_bdev_exclusive(sd.bdev, flags); + + return err; + + cancel_new: + /* Abandoning the newly allocated superblock */ + up(&sd.bdev->bd_mount_sem); + if (nilfs) + put_nilfs(nilfs); + up_write(&s->s_umount); + deactivate_super(s); + /* + * deactivate_super() invokes close_bdev_exclusive(). + * We must finish all post-cleaning before this call; + * put_nilfs() and unlocking bd_mount_sem need the block device. + */ + return err; +} + +static int nilfs_test_bdev_super3(struct super_block *s, void *data) +{ + struct nilfs_super_data *sd = data; + int ret; + + if (s->s_bdev != sd->bdev) + return 0; + if (down_read_trylock(&s->s_umount)) { + ret = (s->s_flags & MS_RDONLY) && s->s_root && + nilfs_test_opt(NILFS_SB(s), SNAPSHOT); + up_read(&s->s_umount); + if (ret) + return 0; /* ignore snapshot mounts */ + } + return !((sd->flags ^ s->s_flags) & MS_RDONLY); +} + +static int __false_bdev_super(struct super_block *s, void *data) +{ +#if 0 /* XXX: workaround for lock debug. This is not good idea */ + up_write(&s->s_umount); +#endif + return -EFAULT; +} + +/** + * test_exclusive_mount - check whether an exclusive RW/RO mount exists or not. + * fs_type: filesystem type + * bdev: block device + * flag: 0 (check rw-mount) or MS_RDONLY (check ro-mount) + * res: pointer to an integer to store result + * + * This function must be called within a section protected by bd_mount_mutex. + */ +static int test_exclusive_mount(struct file_system_type *fs_type, + struct block_device *bdev, int flags) +{ + struct super_block *s; + struct nilfs_super_data sd = { .flags = flags, .bdev = bdev }; + + s = sget(fs_type, nilfs_test_bdev_super3, __false_bdev_super, &sd); + if (IS_ERR(s)) { + if (PTR_ERR(s) != -EFAULT) + return PTR_ERR(s); + return 0; /* Not found */ + } + up_write(&s->s_umount); + deactivate_super(s); + return 1; /* Found */ +} + +struct file_system_type nilfs_fs_type = { + .owner = THIS_MODULE, + .name = "nilfs2", + .get_sb = nilfs_get_sb, + .kill_sb = kill_block_super, + .fs_flags = FS_REQUIRES_DEV, +}; + +static int __init init_nilfs_fs(void) +{ + int err; + + err = nilfs_init_inode_cache(); + if (err) + goto failed; + + err = nilfs_init_transaction_cache(); + if (err) + goto failed_inode_cache; + + err = nilfs_init_segbuf_cache(); + if (err) + goto failed_transaction_cache; + + err = nilfs_btree_path_cache_init(); + if (err) + goto failed_segbuf_cache; + + err = register_filesystem(&nilfs_fs_type); + if (err) + goto failed_btree_path_cache; + + return 0; + + failed_btree_path_cache: + nilfs_btree_path_cache_destroy(); + + failed_segbuf_cache: + nilfs_destroy_segbuf_cache(); + + failed_transaction_cache: + nilfs_destroy_transaction_cache(); + + failed_inode_cache: + nilfs_destroy_inode_cache(); + + failed: + return err; +} + +static void __exit exit_nilfs_fs(void) +{ + nilfs_destroy_segbuf_cache(); + nilfs_destroy_transaction_cache(); + nilfs_destroy_inode_cache(); + nilfs_btree_path_cache_destroy(); + unregister_filesystem(&nilfs_fs_type); +} + +module_init(init_nilfs_fs) +module_exit(exit_nilfs_fs) |