| /* |
| * 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/vfs.h> |
| #include <linux/writeback.h> |
| #include <linux/kobject.h> |
| #include <linux/seq_file.h> |
| #include <linux/mount.h> |
| #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_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_common(struct the_nilfs *nilfs) |
| { |
| 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, nilfs->ns_bdi); |
| return &ii->vfs_inode; |
| } |
| |
| struct inode *nilfs_alloc_inode(struct super_block *sb) |
| { |
| return nilfs_alloc_inode_common(NILFS_SB(sb)->s_nilfs); |
| } |
| |
| 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); |
| } |
| |
| 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 */ |
| |
| root->ifile = nilfs_ifile_new(sbi, nilfs->ns_inode_size); |
| if (!root->ifile) |
| goto failed; |
| |
| 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_read_inode_common(root->ifile, &raw_cp->cp_ifile_inode); |
| if (unlikely(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_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, |
| /* .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]; |
| 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: |
| 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 (match_int(&args[0], &option) || option <= 0) |
| return 0; |
| 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) |
| { |
| 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; |
| |
| 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_state = |
| cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS); |
| sbp[0]->s_mtime = cpu_to_le64(get_seconds()); |
| /* 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); |
| } |
| |
| /** |
| * 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_nilfs; |
| } |
| |
| 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); |
| up_write(&nilfs->ns_sem); |
| } |
| |
| return 0; |
| |
| failed_segctor: |
| nilfs_detach_segment_constructor(sbi); |
| |
| failed_checkpoint: |
| nilfs_put_root(fsroot); |
| |
| 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); |
| 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 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) |
| { |
| 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; |
| } |
| |
| s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev); |
| 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) |