| /* |
| * 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_LICENSE("GPL"); |
| |
| static void nilfs_write_super(struct super_block *sb); |
| 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[0]->s_state |= |
| cpu_to_le16(NILFS_ERROR_FS); |
| nilfs_commit_super(sbi, 1); |
| } |
| 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); |
| |
| #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. |
| */ |
| BUG_ON(!list_empty(&ii->i_dirty)); |
| brelse(ii->i_bh); |
| ii->i_bh = NULL; |
| |
| if (test_bit(NILFS_I_BMAP, &ii->i_state)) |
| nilfs_bmap_clear(ii->i_bmap); |
| |
| nilfs_btnode_cache_clear(&ii->i_btnode_cache); |
| } |
| |
| static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb) |
| { |
| 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[0]); |
| barrier_done = 1; |
| } |
| retry: |
| set_buffer_dirty(nilfs->ns_sbh[0]); |
| err = sync_dirty_buffer(nilfs->ns_sbh[0]); |
| 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[0]); |
| goto retry; |
| } |
| if (unlikely(err)) { |
| printk(KERN_ERR |
| "NILFS: unable to write superblock (err=%d)\n", err); |
| if (err == -EIO && nilfs->ns_sbh[1]) { |
| nilfs_fall_back_super_block(nilfs); |
| goto retry; |
| } |
| } else { |
| struct nilfs_super_block *sbp = nilfs->ns_sbp[0]; |
| |
| /* |
| * The latest segment becomes trailable from the position |
| * written in superblock. |
| */ |
| clear_nilfs_discontinued(nilfs); |
| |
| /* update GC protection for recent segments */ |
| if (nilfs->ns_sbh[1]) { |
| sbp = NULL; |
| if (dupsb) { |
| set_buffer_dirty(nilfs->ns_sbh[1]); |
| if (!sync_dirty_buffer(nilfs->ns_sbh[1])) |
| sbp = nilfs->ns_sbp[1]; |
| } |
| } |
| if (sbp) { |
| spin_lock(&nilfs->ns_last_segment_lock); |
| nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq); |
| spin_unlock(&nilfs->ns_last_segment_lock); |
| } |
| } |
| |
| return err; |
| } |
| |
| int nilfs_commit_super(struct nilfs_sb_info *sbi, int dupsb) |
| { |
| struct the_nilfs *nilfs = sbi->s_nilfs; |
| struct nilfs_super_block **sbp = nilfs->ns_sbp; |
| sector_t nfreeblocks; |
| time_t t; |
| int err; |
| |
| /* nilfs->sem must be locked by the caller. */ |
| if (sbp[0]->s_magic != NILFS_SUPER_MAGIC) { |
| if (sbp[1] && sbp[1]->s_magic == NILFS_SUPER_MAGIC) |
| nilfs_swap_super_block(nilfs); |
| else { |
| printk(KERN_CRIT "NILFS: superblock broke on dev %s\n", |
| sbi->s_super->s_id); |
| return -EIO; |
| } |
| } |
| err = nilfs_count_free_blocks(nilfs, &nfreeblocks); |
| if (unlikely(err)) { |
| printk(KERN_ERR "NILFS: failed to count free blocks\n"); |
| return err; |
| } |
| spin_lock(&nilfs->ns_last_segment_lock); |
| sbp[0]->s_last_seq = cpu_to_le64(nilfs->ns_last_seq); |
| sbp[0]->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg); |
| sbp[0]->s_last_cno = cpu_to_le64(nilfs->ns_last_cno); |
| spin_unlock(&nilfs->ns_last_segment_lock); |
| |
| t = get_seconds(); |
| nilfs->ns_sbwtime[0] = t; |
| sbp[0]->s_free_blocks_count = cpu_to_le64(nfreeblocks); |
| sbp[0]->s_wtime = cpu_to_le64(t); |
| sbp[0]->s_sum = 0; |
| sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed, |
| (unsigned char *)sbp[0], |
| nilfs->ns_sbsize)); |
| if (dupsb && sbp[1]) { |
| memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); |
| nilfs->ns_sbwtime[1] = t; |
| } |
| sbi->s_super->s_dirt = 0; |
| return nilfs_sync_super(sbi, dupsb); |
| } |
| |
| static void nilfs_put_super(struct super_block *sb) |
| { |
| struct nilfs_sb_info *sbi = NILFS_SB(sb); |
| struct the_nilfs *nilfs = sbi->s_nilfs; |
| |
| lock_kernel(); |
| |
| if (sb->s_dirt) |
| nilfs_write_super(sb); |
| |
| nilfs_detach_segment_constructor(sbi); |
| |
| if (!(sb->s_flags & MS_RDONLY)) { |
| down_write(&nilfs->ns_sem); |
| nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state); |
| nilfs_commit_super(sbi, 1); |
| 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); |
| |
| unlock_kernel(); |
| } |
| |
| /** |
| * 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)) { |
| struct nilfs_super_block **sbp = nilfs->ns_sbp; |
| u64 t = get_seconds(); |
| int dupsb; |
| |
| if (!nilfs_discontinued(nilfs) && t >= nilfs->ns_sbwtime[0] && |
| t < nilfs->ns_sbwtime[0] + NILFS_SB_FREQ) { |
| up_write(&nilfs->ns_sem); |
| return; |
| } |
| dupsb = sbp[1] && t > nilfs->ns_sbwtime[1] + NILFS_ALTSB_FREQ; |
| nilfs_commit_super(sbi, dupsb); |
| } |
| sb->s_dirt = 0; |
| up_write(&nilfs->ns_sem); |
| } |
| |
| static int nilfs_sync_fs(struct super_block *sb, int wait) |
| { |
| int err = 0; |
| |
| nilfs_write_super(sb); |
| |
| /* 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, 1); |
| 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); |
| struct the_nilfs *nilfs = sbi->s_nilfs; |
| u64 id = huge_encode_dev(sb->s_bdev->bd_dev); |
| unsigned long long blocks; |
| unsigned long overhead; |
| unsigned long nrsvblocks; |
| sector_t nfreeblocks; |
| 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; |
| buf->f_fsid.val[0] = (u32)id; |
| buf->f_fsid.val[1] = (u32)(id >> 32); |
| |
| 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[0]; |
| 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, 1); |
| } |
| |
| struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb, |
| u64 pos, int blocksize, |
| struct buffer_head **pbh) |
| { |
| unsigned long long sb_index = pos; |
| unsigned long offset; |
| |
| offset = do_div(sb_index, blocksize); |
| *pbh = sb_bread(sb, sb_index); |
| if (!*pbh) |
| return NULL; |
| return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); |
| } |
| |
| 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); |
| |
| sb->s_magic = le16_to_cpu(sbp->s_magic); |
| |
| /* FS independent flags */ |
| #ifdef NILFS_ATIME_DISABLE |
| sb->s_flags |= MS_NOATIME; |
| #endif |
| |
| 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); |
| |
| return !parse_options(data, sb) ? -EINVAL : 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; |
| sb->s_time_gran = 1; |
| |
| 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)) { |
| err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, |
| sbi->s_snapshot_cno); |
| if (err < 0) |
| goto failed_sbi; |
| if (!err) { |
| 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); |
| 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; |
| |
| lock_kernel(); |
| |
| 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[0]; |
| 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, 1); |
| 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); |
| 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: |
| unlock_kernel(); |
| 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; |
| unlock_kernel(); |
| 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); |
| |
| /* |
| * 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; |
| } |
| |
| 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) |