/* * 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 */ /* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include "nilfs.h" #include "export.h" #include "mdt.h" #include "alloc.h" #include "btree.h" #include "btnode.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"); struct kmem_cache *nilfs_inode_cachep; struct kmem_cache *nilfs_transaction_cachep; struct kmem_cache *nilfs_segbuf_cachep; struct kmem_cache *nilfs_btree_path_cache; static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount); static int nilfs_remount(struct super_block *sb, int *flags, char *data); static void nilfs_set_error(struct nilfs_sb_info *sbi) { struct the_nilfs *nilfs = sbi->s_nilfs; struct nilfs_super_block **sbp; down_write(&nilfs->ns_sem); if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) { nilfs->ns_mount_state |= NILFS_ERROR_FS; sbp = nilfs_prepare_super(sbi, 0); if (likely(sbp)) { sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS); if (sbp[1]) sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS); nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL); } } up_write(&nilfs->ns_sem); } /** * 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)) { nilfs_set_error(sbi); 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); } 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->i_cno = 0; ii->vfs_inode.i_version = 1; nilfs_btnode_cache_init(&ii->i_btnode_cache, sb->s_bdi); return &ii->vfs_inode; } void nilfs_destroy_inode(struct inode *inode) { struct nilfs_mdt_info *mdi = NILFS_MDT(inode); if (mdi) { kfree(mdi->mi_bgl); /* kfree(NULL) is safe */ kfree(mdi); } kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode)); } static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag) { struct the_nilfs *nilfs = sbi->s_nilfs; int err; retry: set_buffer_dirty(nilfs->ns_sbh[0]); if (nilfs_test_opt(sbi, BARRIER)) { err = __sync_dirty_buffer(nilfs->ns_sbh[0], WRITE_SYNC | WRITE_BARRIER); if (err == -EOPNOTSUPP) { nilfs_warning(sbi->s_super, __func__, "barrier-based sync failed. " "disabling barriers\n"); nilfs_clear_opt(sbi, BARRIER); goto retry; } } else { err = sync_dirty_buffer(nilfs->ns_sbh[0]); } if (unlikely(err)) { printk(KERN_ERR "NILFS: unable to write superblock (err=%d)\n", err); if (err == -EIO && nilfs->ns_sbh[1]) { /* * sbp[0] points to newer log than sbp[1], * so copy sbp[0] to sbp[1] to take over sbp[0]. */ memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0], nilfs->ns_sbsize); nilfs_fall_back_super_block(nilfs); goto retry; } } else { struct nilfs_super_block *sbp = nilfs->ns_sbp[0]; nilfs->ns_sbwcount++; /* * 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]) { if (flag == NILFS_SB_COMMIT_ALL) { set_buffer_dirty(nilfs->ns_sbh[1]); if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0) goto out; } if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) < le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno)) sbp = nilfs->ns_sbp[1]; } 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); } out: return err; } void nilfs_set_log_cursor(struct nilfs_super_block *sbp, struct the_nilfs *nilfs) { sector_t nfreeblocks; /* nilfs->ns_sem must be locked by the caller. */ nilfs_count_free_blocks(nilfs, &nfreeblocks); sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks); spin_lock(&nilfs->ns_last_segment_lock); 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); } struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi, int flip) { struct the_nilfs *nilfs = sbi->s_nilfs; struct nilfs_super_block **sbp = nilfs->ns_sbp; /* nilfs->ns_sem must be locked by the caller. */ if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { if (sbp[1] && sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) { memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); } else { printk(KERN_CRIT "NILFS: superblock broke on dev %s\n", sbi->s_super->s_id); return NULL; } } else if (sbp[1] && sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); } if (flip && sbp[1]) nilfs_swap_super_block(nilfs); return sbp; } int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag) { struct the_nilfs *nilfs = sbi->s_nilfs; struct nilfs_super_block **sbp = nilfs->ns_sbp; time_t t; /* nilfs->ns_sem must be locked by the caller. */ t = get_seconds(); nilfs->ns_sbwtime = t; 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 (flag == NILFS_SB_COMMIT_ALL && sbp[1]) { sbp[1]->s_wtime = sbp[0]->s_wtime; sbp[1]->s_sum = 0; sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed, (unsigned char *)sbp[1], nilfs->ns_sbsize)); } clear_nilfs_sb_dirty(nilfs); return nilfs_sync_super(sbi, flag); } /** * nilfs_cleanup_super() - write filesystem state for cleanup * @sbi: nilfs_sb_info to be unmounted or degraded to read-only * * This function restores state flags in the on-disk super block. * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the * filesystem was not clean previously. */ int nilfs_cleanup_super(struct nilfs_sb_info *sbi) { struct nilfs_super_block **sbp; int flag = NILFS_SB_COMMIT; int ret = -EIO; sbp = nilfs_prepare_super(sbi, 0); if (sbp) { sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state); nilfs_set_log_cursor(sbp[0], sbi->s_nilfs); if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) { /* * make the "clean" flag also to the opposite * super block if both super blocks point to * the same checkpoint. */ sbp[1]->s_state = sbp[0]->s_state; flag = NILFS_SB_COMMIT_ALL; } ret = nilfs_commit_super(sbi, flag); } return ret; } 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_cleanup_super(sbi); up_write(&nilfs->ns_sem); } iput(nilfs->ns_sufile); iput(nilfs->ns_cpfile); iput(nilfs->ns_dat); destroy_nilfs(nilfs); sbi->s_super = NULL; sb->s_fs_info = NULL; kfree(sbi); } static int nilfs_sync_fs(struct super_block *sb, int wait) { struct nilfs_sb_info *sbi = NILFS_SB(sb); struct the_nilfs *nilfs = sbi->s_nilfs; struct nilfs_super_block **sbp; int err = 0; /* This function is called when super block should be written back */ if (wait) err = nilfs_construct_segment(sb); down_write(&nilfs->ns_sem); if (nilfs_sb_dirty(nilfs)) { sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs)); if (likely(sbp)) { nilfs_set_log_cursor(sbp[0], nilfs); nilfs_commit_super(sbi, NILFS_SB_COMMIT); } } up_write(&nilfs->ns_sem); return err; } int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt, struct nilfs_root **rootp) { struct the_nilfs *nilfs = sbi->s_nilfs; struct nilfs_root *root; struct nilfs_checkpoint *raw_cp; struct buffer_head *bh_cp; int err = -ENOMEM; root = nilfs_find_or_create_root( nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno); if (!root) return err; if (root->ifile) goto reuse; /* already attached checkpoint */ down_read(&nilfs->ns_segctor_sem); err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, &bh_cp); up_read(&nilfs->ns_segctor_sem); 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_ifile_read(sbi->s_super, root, nilfs->ns_inode_size, &raw_cp->cp_ifile_inode, &root->ifile); if (err) goto failed_bh; atomic_set(&root->inodes_count, le64_to_cpu(raw_cp->cp_inodes_count)); atomic_set(&root->blocks_count, le64_to_cpu(raw_cp->cp_blocks_count)); nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); reuse: *rootp = root; return 0; failed_bh: nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); failed: nilfs_put_root(root); return err; } static int nilfs_freeze(struct super_block *sb) { struct nilfs_sb_info *sbi = NILFS_SB(sb); struct the_nilfs *nilfs = sbi->s_nilfs; int err; if (sb->s_flags & MS_RDONLY) return 0; /* Mark super block clean */ down_write(&nilfs->ns_sem); err = nilfs_cleanup_super(sbi); up_write(&nilfs->ns_sem); return err; } static int nilfs_unfreeze(struct super_block *sb) { struct nilfs_sb_info *sbi = NILFS_SB(sb); struct the_nilfs *nilfs = sbi->s_nilfs; if (sb->s_flags & MS_RDONLY) return 0; down_write(&nilfs->ns_sem); nilfs_setup_super(sbi, false); up_write(&nilfs->ns_sem); return 0; } static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct super_block *sb = dentry->d_sb; struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root; struct the_nilfs *nilfs = root->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 segment 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(&root->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 int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs) { struct super_block *sb = vfs->mnt_sb; struct nilfs_sb_info *sbi = NILFS_SB(sb); struct nilfs_root *root = NILFS_I(vfs->mnt_root->d_inode)->i_root; if (!nilfs_test_opt(sbi, BARRIER)) seq_puts(seq, ",nobarrier"); if (root->cno != NILFS_CPTREE_CURRENT_CNO) seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno); if (nilfs_test_opt(sbi, ERRORS_PANIC)) seq_puts(seq, ",errors=panic"); if (nilfs_test_opt(sbi, ERRORS_CONT)) seq_puts(seq, ",errors=continue"); if (nilfs_test_opt(sbi, STRICT_ORDER)) seq_puts(seq, ",order=strict"); if (nilfs_test_opt(sbi, NORECOVERY)) seq_puts(seq, ",norecovery"); if (nilfs_test_opt(sbi, DISCARD)) seq_puts(seq, ",discard"); return 0; } static const 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, */ .evict_inode = nilfs_evict_inode, .put_super = nilfs_put_super, /* .write_super = nilfs_write_super, */ .sync_fs = nilfs_sync_fs, .freeze_fs = nilfs_freeze, .unfreeze_fs = nilfs_unfreeze, /* .write_super_lockfs */ /* .unlockfs */ .statfs = nilfs_statfs, .remount_fs = nilfs_remount, /* .umount_begin */ .show_options = nilfs_show_options }; enum { Opt_err_cont, Opt_err_panic, Opt_err_ro, Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery, Opt_discard, Opt_nodiscard, 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"}, {Opt_nobarrier, "nobarrier"}, {Opt_snapshot, "cp=%u"}, {Opt_order, "order=%s"}, {Opt_norecovery, "norecovery"}, {Opt_discard, "discard"}, {Opt_nodiscard, "nodiscard"}, {Opt_err, NULL} }; static int parse_options(char *options, struct super_block *sb, int is_remount) { struct nilfs_sb_info *sbi = NILFS_SB(sb); char *p; substring_t args[MAX_OPT_ARGS]; 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: nilfs_set_opt(sbi, BARRIER); break; case Opt_nobarrier: 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 (is_remount) { printk(KERN_ERR "NILFS: \"%s\" option is invalid " "for remount.\n", p); return 0; } break; case Opt_norecovery: nilfs_set_opt(sbi, NORECOVERY); break; case Opt_discard: nilfs_set_opt(sbi, DISCARD); break; case Opt_nodiscard: nilfs_clear_opt(sbi, DISCARD); 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_RO | NILFS_MOUNT_BARRIER; } static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount) { struct the_nilfs *nilfs = sbi->s_nilfs; struct nilfs_super_block **sbp; int max_mnt_count; int mnt_count; /* nilfs->ns_sem must be locked by the caller. */ sbp = nilfs_prepare_super(sbi, 0); if (!sbp) return -EIO; if (!is_mount) goto skip_mount_setup; max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count); mnt_count = le16_to_cpu(sbp[0]->s_mnt_count); 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[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT); sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1); sbp[0]->s_mtime = cpu_to_le64(get_seconds()); skip_mount_setup: sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS); /* synchronize sbp[1] with sbp[0] */ memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL); } 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, 0) ? -EINVAL : 0 ; } int nilfs_check_feature_compatibility(struct super_block *sb, struct nilfs_super_block *sbp) { __u64 features; features = le64_to_cpu(sbp->s_feature_incompat) & ~NILFS_FEATURE_INCOMPAT_SUPP; if (features) { printk(KERN_ERR "NILFS: couldn't mount because of unsupported " "optional features (%llx)\n", (unsigned long long)features); return -EINVAL; } features = le64_to_cpu(sbp->s_feature_compat_ro) & ~NILFS_FEATURE_COMPAT_RO_SUPP; if (!(sb->s_flags & MS_RDONLY) && features) { printk(KERN_ERR "NILFS: couldn't mount RDWR because of " "unsupported optional features (%llx)\n", (unsigned long long)features); return -EINVAL; } return 0; } static int nilfs_get_root_dentry(struct super_block *sb, struct nilfs_root *root, struct dentry **root_dentry) { struct inode *inode; struct dentry *dentry; int ret = 0; inode = nilfs_iget(sb, root, NILFS_ROOT_INO); if (IS_ERR(inode)) { printk(KERN_ERR "NILFS: get root inode failed\n"); ret = PTR_ERR(inode); goto out; } if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) { iput(inode); printk(KERN_ERR "NILFS: corrupt root inode.\n"); ret = -EINVAL; goto out; } if (root->cno == NILFS_CPTREE_CURRENT_CNO) { dentry = d_find_alias(inode); if (!dentry) { dentry = d_alloc_root(inode); if (!dentry) { iput(inode); ret = -ENOMEM; goto failed_dentry; } } else { iput(inode); } } else { dentry = d_obtain_alias(inode); if (IS_ERR(dentry)) { ret = PTR_ERR(dentry); goto failed_dentry; } } *root_dentry = dentry; out: return ret; failed_dentry: printk(KERN_ERR "NILFS: get root dentry failed\n"); goto out; } static int nilfs_attach_snapshot(struct super_block *s, __u64 cno, struct dentry **root_dentry) { struct the_nilfs *nilfs = NILFS_SB(s)->s_nilfs; struct nilfs_root *root; int ret; down_read(&nilfs->ns_segctor_sem); ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno); up_read(&nilfs->ns_segctor_sem); if (ret < 0) { ret = (ret == -ENOENT) ? -EINVAL : ret; goto out; } else if (!ret) { printk(KERN_ERR "NILFS: The specified checkpoint is " "not a snapshot (checkpoint number=%llu).\n", (unsigned long long)cno); ret = -EINVAL; goto out; } ret = nilfs_attach_checkpoint(NILFS_SB(s), cno, false, &root); if (ret) { printk(KERN_ERR "NILFS: error loading snapshot " "(checkpoint number=%llu).\n", (unsigned long long)cno); goto out; } ret = nilfs_get_root_dentry(s, root, root_dentry); nilfs_put_root(root); out: return ret; } static int nilfs_tree_was_touched(struct dentry *root_dentry) { return atomic_read(&root_dentry->d_count) > 1; } /** * nilfs_try_to_shrink_tree() - try to shrink dentries of a checkpoint * @root_dentry: root dentry of the tree to be shrunk * * This function returns true if the tree was in-use. */ static int nilfs_try_to_shrink_tree(struct dentry *root_dentry) { if (have_submounts(root_dentry)) return true; shrink_dcache_parent(root_dentry); return nilfs_tree_was_touched(root_dentry); } int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno) { struct the_nilfs *nilfs = NILFS_SB(sb)->s_nilfs; struct nilfs_root *root; struct inode *inode; struct dentry *dentry; int ret; if (cno < 0 || cno > nilfs->ns_cno) return false; if (cno >= nilfs_last_cno(nilfs)) return true; /* protect recent checkpoints */ ret = false; root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs, cno); if (root) { inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO); if (inode) { dentry = d_find_alias(inode); if (dentry) { if (nilfs_tree_was_touched(dentry)) ret = nilfs_try_to_shrink_tree(dentry); dput(dentry); } iput(inode); } nilfs_put_root(root); } return ret; } /** * nilfs_fill_super() - initialize a super block instance * @sb: super_block * @data: mount options * @silent: silent mode flag * * This function is called exclusively by nilfs->ns_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 nilfs_root *fsroot; __u64 cno; int err; sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); if (!sbi) return -ENOMEM; sb->s_fs_info = sbi; sbi->s_super = sb; nilfs = alloc_nilfs(sb->s_bdev); if (!nilfs) { err = -ENOMEM; goto failed_sbi; } sbi->s_nilfs = nilfs; err = init_nilfs(nilfs, sbi, (char *)data); if (err) goto failed_nilfs; spin_lock_init(&sbi->s_inode_lock); INIT_LIST_HEAD(&sbi->s_dirty_files); /* * 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; sb->s_bdi = nilfs->ns_bdi; err = load_nilfs(nilfs, sbi); if (err) goto failed_nilfs; cno = nilfs_last_cno(nilfs); err = nilfs_attach_checkpoint(sbi, cno, true, &fsroot); if (err) { printk(KERN_ERR "NILFS: error loading last checkpoint " "(checkpoint number=%llu).\n", (unsigned long long)cno); goto failed_unload; } if (!(sb->s_flags & MS_RDONLY)) { err = nilfs_attach_segment_constructor(sbi, fsroot); if (err) goto failed_checkpoint; } err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root); if (err) goto failed_segctor; nilfs_put_root(fsroot); if (!(sb->s_flags & MS_RDONLY)) { down_write(&nilfs->ns_sem); nilfs_setup_super(sbi, true); up_write(&nilfs->ns_sem); } return 0; failed_segctor: nilfs_detach_segment_constructor(sbi); failed_checkpoint: nilfs_put_root(fsroot); failed_unload: iput(nilfs->ns_sufile); iput(nilfs->ns_cpfile); iput(nilfs->ns_dat); failed_nilfs: destroy_nilfs(nilfs); failed_sbi: 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 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; if (!parse_options(data, sb, 1)) { err = -EINVAL; goto restore_opts; } sb->s_flags = (sb->s_flags & ~MS_POSIXACL); err = -EINVAL; if (!nilfs_valid_fs(nilfs)) { printk(KERN_WARNING "NILFS (device %s): couldn't " "remount because the filesystem is in an " "incomplete recovery state.\n", sb->s_id); 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; /* * Remounting a valid RW partition RDONLY, so set * the RDONLY flag and then mark the partition as valid again. */ down_write(&nilfs->ns_sem); nilfs_cleanup_super(sbi); up_write(&nilfs->ns_sem); } else { __u64 features; struct nilfs_root *root; /* * 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_read(&nilfs->ns_sem); features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & ~NILFS_FEATURE_COMPAT_RO_SUPP; up_read(&nilfs->ns_sem); if (features) { printk(KERN_WARNING "NILFS (device %s): couldn't " "remount RDWR because of unsupported optional " "features (%llx)\n", sb->s_id, (unsigned long long)features); err = -EROFS; goto restore_opts; } sb->s_flags &= ~MS_RDONLY; root = NILFS_I(sb->s_root->d_inode)->i_root; err = nilfs_attach_segment_constructor(sbi, root); if (err) goto restore_opts; down_write(&nilfs->ns_sem); nilfs_setup_super(sbi, true); up_write(&nilfs->ns_sem); } out: return 0; restore_opts: sb->s_flags = old_sb_flags; sbi->s_mount_opt = old_opts.mount_opt; return err; } struct nilfs_super_data { struct block_device *bdev; struct nilfs_sb_info *sbi; __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 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 { sd->cno = simple_strtoull(args[0].from, NULL, 0); /* * No need to see the end pointer; * match_token() has done syntax * checking. */ if (sd->cno == 0) 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) { s->s_bdev = data; s->s_dev = s->s_bdev->bd_dev; return 0; } static int nilfs_test_bdev_super(struct super_block *s, void *data) { return (void *)s->s_bdev == data; } 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; fmode_t mode = FMODE_READ; struct dentry *root_dentry; int err, s_new = false; if (!(flags & MS_RDONLY)) mode |= FMODE_WRITE; sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type); if (IS_ERR(sd.bdev)) return PTR_ERR(sd.bdev); 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 */ mutex_lock(&sd.bdev->bd_fsfreeze_mutex); if (sd.bdev->bd_fsfreeze_count > 0) { mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); err = -EBUSY; goto failed; } s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev); mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); if (IS_ERR(s)) { err = PTR_ERR(s); goto failed; } if (!s->s_root) { char b[BDEVNAME_SIZE]; s_new = true; /* New superblock instance created */ s->s_flags = flags; s->s_mode = mode; 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_SILENT ? 1 : 0); if (err) goto failed_super; s->s_flags |= MS_ACTIVE; } else if (!sd.cno) { int busy = false; if (nilfs_tree_was_touched(s->s_root)) { busy = nilfs_try_to_shrink_tree(s->s_root); if (busy && (flags ^ s->s_flags) & MS_RDONLY) { printk(KERN_ERR "NILFS: the device already " "has a %s mount.\n", (s->s_flags & MS_RDONLY) ? "read-only" : "read/write"); err = -EBUSY; goto failed_super; } } if (!busy) { /* * Try remount to setup mount states if the current * tree is not mounted and only snapshots use this sb. */ err = nilfs_remount(s, &flags, data); if (err) goto failed_super; } } if (sd.cno) { err = nilfs_attach_snapshot(s, sd.cno, &root_dentry); if (err) goto failed_super; } else { root_dentry = dget(s->s_root); } if (!s_new) close_bdev_exclusive(sd.bdev, mode); mnt->mnt_sb = s; mnt->mnt_root = root_dentry; return 0; failed_super: deactivate_locked_super(s); failed: if (!s_new) close_bdev_exclusive(sd.bdev, mode); return err; } 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 void nilfs_inode_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 = &ii->i_bmap_data; inode_init_once(&ii->vfs_inode); } static void nilfs_segbuf_init_once(void *obj) { memset(obj, 0, sizeof(struct nilfs_segment_buffer)); } static void nilfs_destroy_cachep(void) { if (nilfs_inode_cachep) kmem_cache_destroy(nilfs_inode_cachep); if (nilfs_transaction_cachep) kmem_cache_destroy(nilfs_transaction_cachep); if (nilfs_segbuf_cachep) kmem_cache_destroy(nilfs_segbuf_cachep); if (nilfs_btree_path_cache) kmem_cache_destroy(nilfs_btree_path_cache); } static int __init nilfs_init_cachep(void) { nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache", sizeof(struct nilfs_inode_info), 0, SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once); if (!nilfs_inode_cachep) goto fail; nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache", sizeof(struct nilfs_transaction_info), 0, SLAB_RECLAIM_ACCOUNT, NULL); if (!nilfs_transaction_cachep) goto fail; nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache", sizeof(struct nilfs_segment_buffer), 0, SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once); if (!nilfs_segbuf_cachep) goto fail; nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache", sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX, 0, 0, NULL); if (!nilfs_btree_path_cache) goto fail; return 0; fail: nilfs_destroy_cachep(); return -ENOMEM; } static int __init init_nilfs_fs(void) { int err; err = nilfs_init_cachep(); if (err) goto fail; err = register_filesystem(&nilfs_fs_type); if (err) goto free_cachep; printk(KERN_INFO "NILFS version 2 loaded\n"); return 0; free_cachep: nilfs_destroy_cachep(); fail: return err; } static void __exit exit_nilfs_fs(void) { nilfs_destroy_cachep(); unregister_filesystem(&nilfs_fs_type); } module_init(init_nilfs_fs) module_exit(exit_nilfs_fs)