diff options
Diffstat (limited to 'fs/nilfs2/super.c')
| -rw-r--r-- | fs/nilfs2/super.c | 1477 |
1 files changed, 1477 insertions, 0 deletions
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c new file mode 100644 index 0000000000..a5d1fa4e75 --- /dev/null +++ b/fs/nilfs2/super.c @@ -0,0 +1,1477 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * NILFS module and super block management. + * + * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. + * + * 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 <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/crc32.h> +#include <linux/vfs.h> +#include <linux/writeback.h> +#include <linux/seq_file.h> +#include <linux/mount.h> +#include <linux/fs_context.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 "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */ +#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 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 super_block *sb, int is_mount); +static int nilfs_remount(struct super_block *sb, int *flags, char *data); + +void __nilfs_msg(struct super_block *sb, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + int level; + + va_start(args, fmt); + + level = printk_get_level(fmt); + vaf.fmt = printk_skip_level(fmt); + vaf.va = &args; + + if (sb) + printk("%c%cNILFS (%s): %pV\n", + KERN_SOH_ASCII, level, sb->s_id, &vaf); + else + printk("%c%cNILFS: %pV\n", + KERN_SOH_ASCII, level, &vaf); + + va_end(args); +} + +static void nilfs_set_error(struct super_block *sb) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + 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(sb, 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(sb, 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. This function should be called when + * NILFS detects incoherences or defects of meta data on disk. + * + * This implements the body of nilfs_error() macro. Normally, + * nilfs_error() should be used. As for sustainable errors such as a + * single-shot I/O error, nilfs_err() should be used instead. + * + * Callers should not add a trailing newline since this will do it. + */ +void __nilfs_error(struct super_block *sb, const char *function, + const char *fmt, ...) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n", + sb->s_id, function, &vaf); + + va_end(args); + + if (!sb_rdonly(sb)) { + nilfs_set_error(sb); + + if (nilfs_test_opt(nilfs, ERRORS_RO)) { + printk(KERN_CRIT "Remounting filesystem read-only\n"); + sb->s_flags |= SB_RDONLY; + } + } + + if (nilfs_test_opt(nilfs, ERRORS_PANIC)) + panic("NILFS (device %s): panic forced after error\n", + sb->s_id); +} + +struct inode *nilfs_alloc_inode(struct super_block *sb) +{ + struct nilfs_inode_info *ii; + + ii = alloc_inode_sb(sb, nilfs_inode_cachep, GFP_NOFS); + if (!ii) + return NULL; + ii->i_bh = NULL; + ii->i_state = 0; + ii->i_cno = 0; + ii->i_assoc_inode = NULL; + ii->i_bmap = &ii->i_bmap_data; + return &ii->vfs_inode; +} + +static void nilfs_free_inode(struct inode *inode) +{ + if (nilfs_is_metadata_file_inode(inode)) + nilfs_mdt_destroy(inode); + + kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode)); +} + +static int nilfs_sync_super(struct super_block *sb, int flag) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + int err; + + retry: + set_buffer_dirty(nilfs->ns_sbh[0]); + if (nilfs_test_opt(nilfs, BARRIER)) { + err = __sync_dirty_buffer(nilfs->ns_sbh[0], + REQ_SYNC | REQ_PREFLUSH | REQ_FUA); + } else { + err = sync_dirty_buffer(nilfs->ns_sbh[0]); + } + + if (unlikely(err)) { + nilfs_err(sb, "unable to write superblock: err=%d", 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 super_block *sb, + int flip) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + 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 { + nilfs_crit(sb, "superblock broke"); + 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 super_block *sb, int flag) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + struct nilfs_super_block **sbp = nilfs->ns_sbp; + time64_t t; + + /* nilfs->ns_sem must be locked by the caller. */ + t = ktime_get_real_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); + nilfs->ns_flushed_device = 1; + /* make sure store to ns_flushed_device cannot be reordered */ + smp_wmb(); + return nilfs_sync_super(sb, flag); +} + +/** + * nilfs_cleanup_super() - write filesystem state for cleanup + * @sb: super block instance 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 super_block *sb) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + struct nilfs_super_block **sbp; + int flag = NILFS_SB_COMMIT; + int ret = -EIO; + + sbp = nilfs_prepare_super(sb, 0); + if (sbp) { + sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state); + nilfs_set_log_cursor(sbp[0], 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(sb, flag); + } + return ret; +} + +/** + * nilfs_move_2nd_super - relocate secondary super block + * @sb: super block instance + * @sb2off: new offset of the secondary super block (in bytes) + */ +static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + struct buffer_head *nsbh; + struct nilfs_super_block *nsbp; + sector_t blocknr, newblocknr; + unsigned long offset; + int sb2i; /* array index of the secondary superblock */ + int ret = 0; + + /* nilfs->ns_sem must be locked by the caller. */ + if (nilfs->ns_sbh[1] && + nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) { + sb2i = 1; + blocknr = nilfs->ns_sbh[1]->b_blocknr; + } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) { + sb2i = 0; + blocknr = nilfs->ns_sbh[0]->b_blocknr; + } else { + sb2i = -1; + blocknr = 0; + } + if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off) + goto out; /* super block location is unchanged */ + + /* Get new super block buffer */ + newblocknr = sb2off >> nilfs->ns_blocksize_bits; + offset = sb2off & (nilfs->ns_blocksize - 1); + nsbh = sb_getblk(sb, newblocknr); + if (!nsbh) { + nilfs_warn(sb, + "unable to move secondary superblock to block %llu", + (unsigned long long)newblocknr); + ret = -EIO; + goto out; + } + nsbp = (void *)nsbh->b_data + offset; + + lock_buffer(nsbh); + if (sb2i >= 0) { + /* + * The position of the second superblock only changes by 4KiB, + * which is larger than the maximum superblock data size + * (= 1KiB), so there is no need to use memmove() to allow + * overlap between source and destination. + */ + memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize); + + /* + * Zero fill after copy to avoid overwriting in case of move + * within the same block. + */ + memset(nsbh->b_data, 0, offset); + memset((void *)nsbp + nilfs->ns_sbsize, 0, + nsbh->b_size - offset - nilfs->ns_sbsize); + } else { + memset(nsbh->b_data, 0, nsbh->b_size); + } + set_buffer_uptodate(nsbh); + unlock_buffer(nsbh); + + if (sb2i >= 0) { + brelse(nilfs->ns_sbh[sb2i]); + nilfs->ns_sbh[sb2i] = nsbh; + nilfs->ns_sbp[sb2i] = nsbp; + } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) { + /* secondary super block will be restored to index 1 */ + nilfs->ns_sbh[1] = nsbh; + nilfs->ns_sbp[1] = nsbp; + } else { + brelse(nsbh); + } +out: + return ret; +} + +/** + * nilfs_resize_fs - resize the filesystem + * @sb: super block instance + * @newsize: new size of the filesystem (in bytes) + */ +int nilfs_resize_fs(struct super_block *sb, __u64 newsize) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + struct nilfs_super_block **sbp; + __u64 devsize, newnsegs; + loff_t sb2off; + int ret; + + ret = -ERANGE; + devsize = bdev_nr_bytes(sb->s_bdev); + if (newsize > devsize) + goto out; + + /* + * Prevent underflow in second superblock position calculation. + * The exact minimum size check is done in nilfs_sufile_resize(). + */ + if (newsize < 4096) { + ret = -ENOSPC; + goto out; + } + + /* + * Write lock is required to protect some functions depending + * on the number of segments, the number of reserved segments, + * and so forth. + */ + down_write(&nilfs->ns_segctor_sem); + + sb2off = NILFS_SB2_OFFSET_BYTES(newsize); + newnsegs = sb2off >> nilfs->ns_blocksize_bits; + do_div(newnsegs, nilfs->ns_blocks_per_segment); + + ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs); + up_write(&nilfs->ns_segctor_sem); + if (ret < 0) + goto out; + + ret = nilfs_construct_segment(sb); + if (ret < 0) + goto out; + + down_write(&nilfs->ns_sem); + nilfs_move_2nd_super(sb, sb2off); + ret = -EIO; + sbp = nilfs_prepare_super(sb, 0); + if (likely(sbp)) { + nilfs_set_log_cursor(sbp[0], nilfs); + /* + * Drop NILFS_RESIZE_FS flag for compatibility with + * mount-time resize which may be implemented in a + * future release. + */ + sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & + ~NILFS_RESIZE_FS); + sbp[0]->s_dev_size = cpu_to_le64(newsize); + sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments); + if (sbp[1]) + memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); + ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL); + } + up_write(&nilfs->ns_sem); + + /* + * Reset the range of allocatable segments last. This order + * is important in the case of expansion because the secondary + * superblock must be protected from log write until migration + * completes. + */ + if (!ret) + nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1); +out: + return ret; +} + +static void nilfs_put_super(struct super_block *sb) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + + nilfs_detach_log_writer(sb); + + if (!sb_rdonly(sb)) { + down_write(&nilfs->ns_sem); + nilfs_cleanup_super(sb); + up_write(&nilfs->ns_sem); + } + + nilfs_sysfs_delete_device_group(nilfs); + iput(nilfs->ns_sufile); + iput(nilfs->ns_cpfile); + iput(nilfs->ns_dat); + + destroy_nilfs(nilfs); + sb->s_fs_info = NULL; +} + +static int nilfs_sync_fs(struct super_block *sb, int wait) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + 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(sb, nilfs_sb_will_flip(nilfs)); + if (likely(sbp)) { + nilfs_set_log_cursor(sbp[0], nilfs); + nilfs_commit_super(sb, NILFS_SB_COMMIT); + } + } + up_write(&nilfs->ns_sem); + + if (!err) + err = nilfs_flush_device(nilfs); + + return err; +} + +int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt, + struct nilfs_root **rootp) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + 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) { + nilfs_err(sb, + "Invalid checkpoint (checkpoint number=%llu)", + (unsigned long long)cno); + err = -EINVAL; + } + goto failed; + } + + err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size, + &raw_cp->cp_ifile_inode, &root->ifile); + if (err) + goto failed_bh; + + atomic64_set(&root->inodes_count, + le64_to_cpu(raw_cp->cp_inodes_count)); + atomic64_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 the_nilfs *nilfs = sb->s_fs_info; + int err; + + if (sb_rdonly(sb)) + return 0; + + /* Mark super block clean */ + down_write(&nilfs->ns_sem); + err = nilfs_cleanup_super(sb); + up_write(&nilfs->ns_sem); + return err; +} + +static int nilfs_unfreeze(struct super_block *sb) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + + if (sb_rdonly(sb)) + return 0; + + down_write(&nilfs->ns_sem); + nilfs_setup_super(sb, 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(d_inode(dentry))->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; + u64 nmaxinodes, nfreeinodes; + 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; + + err = nilfs_ifile_count_free_inodes(root->ifile, + &nmaxinodes, &nfreeinodes); + if (unlikely(err)) { + nilfs_warn(sb, "failed to count free inodes: err=%d", err); + if (err == -ERANGE) { + /* + * If nilfs_palloc_count_max_entries() returns + * -ERANGE error code then we simply treat + * curent inodes count as maximum possible and + * zero as free inodes value. + */ + nmaxinodes = atomic64_read(&root->inodes_count); + nfreeinodes = 0; + err = 0; + } else + 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 = nmaxinodes; + buf->f_ffree = nfreeinodes; + buf->f_namelen = NILFS_NAME_LEN; + buf->f_fsid = u64_to_fsid(id); + + return 0; +} + +static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry) +{ + struct super_block *sb = dentry->d_sb; + struct the_nilfs *nilfs = sb->s_fs_info; + struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root; + + if (!nilfs_test_opt(nilfs, 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(nilfs, ERRORS_PANIC)) + seq_puts(seq, ",errors=panic"); + if (nilfs_test_opt(nilfs, ERRORS_CONT)) + seq_puts(seq, ",errors=continue"); + if (nilfs_test_opt(nilfs, STRICT_ORDER)) + seq_puts(seq, ",order=strict"); + if (nilfs_test_opt(nilfs, NORECOVERY)) + seq_puts(seq, ",norecovery"); + if (nilfs_test_opt(nilfs, DISCARD)) + seq_puts(seq, ",discard"); + + return 0; +} + +static const struct super_operations nilfs_sops = { + .alloc_inode = nilfs_alloc_inode, + .free_inode = nilfs_free_inode, + .dirty_inode = nilfs_dirty_inode, + .evict_inode = nilfs_evict_inode, + .put_super = nilfs_put_super, + .sync_fs = nilfs_sync_fs, + .freeze_fs = nilfs_freeze, + .unfreeze_fs = nilfs_unfreeze, + .statfs = nilfs_statfs, + .remount_fs = nilfs_remount, + .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 the_nilfs *nilfs = sb->s_fs_info; + 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(nilfs, BARRIER); + break; + case Opt_nobarrier: + nilfs_clear_opt(nilfs, BARRIER); + break; + case Opt_order: + if (strcmp(args[0].from, "relaxed") == 0) + /* Ordered data semantics */ + nilfs_clear_opt(nilfs, STRICT_ORDER); + else if (strcmp(args[0].from, "strict") == 0) + /* Strict in-order semantics */ + nilfs_set_opt(nilfs, STRICT_ORDER); + else + return 0; + break; + case Opt_err_panic: + nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC); + break; + case Opt_err_ro: + nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO); + break; + case Opt_err_cont: + nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT); + break; + case Opt_snapshot: + if (is_remount) { + nilfs_err(sb, + "\"%s\" option is invalid for remount", + p); + return 0; + } + break; + case Opt_norecovery: + nilfs_set_opt(nilfs, NORECOVERY); + break; + case Opt_discard: + nilfs_set_opt(nilfs, DISCARD); + break; + case Opt_nodiscard: + nilfs_clear_opt(nilfs, DISCARD); + break; + default: + nilfs_err(sb, "unrecognized mount option \"%s\"", p); + return 0; + } + } + return 1; +} + +static inline void +nilfs_set_default_options(struct super_block *sb, + struct nilfs_super_block *sbp) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + + nilfs->ns_mount_opt = + NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER; +} + +static int nilfs_setup_super(struct super_block *sb, int is_mount) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + 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(sb, 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) { + nilfs_warn(sb, "mounting fs with errors"); +#if 0 + } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) { + nilfs_warn(sb, "maximal mount count reached"); +#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(ktime_get_real_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] */ + if (sbp[1]) + memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); + return nilfs_commit_super(sb, 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 the_nilfs *nilfs = sb->s_fs_info; + + sb->s_magic = le16_to_cpu(sbp->s_magic); + + /* FS independent flags */ +#ifdef NILFS_ATIME_DISABLE + sb->s_flags |= SB_NOATIME; +#endif + + nilfs_set_default_options(sb, sbp); + + nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid); + nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid); + nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval); + nilfs->ns_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) { + nilfs_err(sb, + "couldn't mount because of unsupported optional features (%llx)", + (unsigned long long)features); + return -EINVAL; + } + features = le64_to_cpu(sbp->s_feature_compat_ro) & + ~NILFS_FEATURE_COMPAT_RO_SUPP; + if (!sb_rdonly(sb) && features) { + nilfs_err(sb, + "couldn't mount RDWR because of unsupported optional features (%llx)", + (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)) { + ret = PTR_ERR(inode); + nilfs_err(sb, "error %d getting root inode", ret); + goto out; + } + if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) { + iput(inode); + nilfs_err(sb, "corrupt root inode"); + ret = -EINVAL; + goto out; + } + + if (root->cno == NILFS_CPTREE_CURRENT_CNO) { + dentry = d_find_alias(inode); + if (!dentry) { + dentry = d_make_root(inode); + if (!dentry) { + ret = -ENOMEM; + goto failed_dentry; + } + } else { + iput(inode); + } + } else { + dentry = d_obtain_root(inode); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto failed_dentry; + } + } + *root_dentry = dentry; + out: + return ret; + + failed_dentry: + nilfs_err(sb, "error %d getting root dentry", ret); + goto out; +} + +static int nilfs_attach_snapshot(struct super_block *s, __u64 cno, + struct dentry **root_dentry) +{ + struct the_nilfs *nilfs = s->s_fs_info; + struct nilfs_root *root; + int ret; + + mutex_lock(&nilfs->ns_snapshot_mount_mutex); + + 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) { + nilfs_err(s, + "The specified checkpoint is not a snapshot (checkpoint number=%llu)", + (unsigned long long)cno); + ret = -EINVAL; + goto out; + } + + ret = nilfs_attach_checkpoint(s, cno, false, &root); + if (ret) { + nilfs_err(s, + "error %d while loading snapshot (checkpoint number=%llu)", + ret, (unsigned long long)cno); + goto out; + } + ret = nilfs_get_root_dentry(s, root, root_dentry); + nilfs_put_root(root); + out: + mutex_unlock(&nilfs->ns_snapshot_mount_mutex); + return ret; +} + +/** + * nilfs_tree_is_busy() - 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 bool nilfs_tree_is_busy(struct dentry *root_dentry) +{ + shrink_dcache_parent(root_dentry); + return d_count(root_dentry) > 1; +} + +int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + struct nilfs_root *root; + struct inode *inode; + struct dentry *dentry; + int ret; + + if (cno > nilfs->ns_cno) + return false; + + if (cno >= nilfs_last_cno(nilfs)) + return true; /* protect recent checkpoints */ + + ret = false; + root = nilfs_lookup_root(nilfs, cno); + if (root) { + inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO); + if (inode) { + dentry = d_find_alias(inode); + if (dentry) { + ret = nilfs_tree_is_busy(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_root *fsroot; + __u64 cno; + int err; + + nilfs = alloc_nilfs(sb); + if (!nilfs) + return -ENOMEM; + + sb->s_fs_info = nilfs; + + err = init_nilfs(nilfs, sb, (char *)data); + if (err) + goto failed_nilfs; + + sb->s_op = &nilfs_sops; + sb->s_export_op = &nilfs_export_ops; + sb->s_root = NULL; + sb->s_time_gran = 1; + sb->s_max_links = NILFS_LINK_MAX; + + sb->s_bdi = bdi_get(sb->s_bdev->bd_disk->bdi); + + err = load_nilfs(nilfs, sb); + if (err) + goto failed_nilfs; + + cno = nilfs_last_cno(nilfs); + err = nilfs_attach_checkpoint(sb, cno, true, &fsroot); + if (err) { + nilfs_err(sb, + "error %d while loading last checkpoint (checkpoint number=%llu)", + err, (unsigned long long)cno); + goto failed_unload; + } + + if (!sb_rdonly(sb)) { + err = nilfs_attach_log_writer(sb, 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_rdonly(sb)) { + down_write(&nilfs->ns_sem); + nilfs_setup_super(sb, true); + up_write(&nilfs->ns_sem); + } + + return 0; + + failed_segctor: + nilfs_detach_log_writer(sb); + + failed_checkpoint: + nilfs_put_root(fsroot); + + failed_unload: + nilfs_sysfs_delete_device_group(nilfs); + iput(nilfs->ns_sufile); + iput(nilfs->ns_cpfile); + iput(nilfs->ns_dat); + + failed_nilfs: + destroy_nilfs(nilfs); + return err; +} + +static int nilfs_remount(struct super_block *sb, int *flags, char *data) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + unsigned long old_sb_flags; + unsigned long old_mount_opt; + int err; + + sync_filesystem(sb); + old_sb_flags = sb->s_flags; + old_mount_opt = nilfs->ns_mount_opt; + + if (!parse_options(data, sb, 1)) { + err = -EINVAL; + goto restore_opts; + } + sb->s_flags = (sb->s_flags & ~SB_POSIXACL); + + err = -EINVAL; + + if (!nilfs_valid_fs(nilfs)) { + nilfs_warn(sb, + "couldn't remount because the filesystem is in an incomplete recovery state"); + goto restore_opts; + } + + if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb)) + goto out; + if (*flags & SB_RDONLY) { + sb->s_flags |= SB_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(sb); + 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) { + nilfs_warn(sb, + "couldn't remount RDWR because of unsupported optional features (%llx)", + (unsigned long long)features); + err = -EROFS; + goto restore_opts; + } + + sb->s_flags &= ~SB_RDONLY; + + root = NILFS_I(d_inode(sb->s_root))->i_root; + err = nilfs_attach_log_writer(sb, root); + if (err) + goto restore_opts; + + down_write(&nilfs->ns_sem); + nilfs_setup_super(sb, true); + up_write(&nilfs->ns_sem); + } + out: + return 0; + + restore_opts: + sb->s_flags = old_sb_flags; + nilfs->ns_mount_opt = old_mount_opt; + return err; +} + +struct nilfs_super_data { + __u64 cno; + int flags; +}; + +static int nilfs_parse_snapshot_option(const char *option, + const substring_t *arg, + struct nilfs_super_data *sd) +{ + unsigned long long val; + const char *msg = NULL; + int err; + + if (!(sd->flags & SB_RDONLY)) { + msg = "read-only option is not specified"; + goto parse_error; + } + + err = kstrtoull(arg->from, 0, &val); + if (err) { + if (err == -ERANGE) + msg = "too large checkpoint number"; + else + msg = "malformed argument"; + goto parse_error; + } else if (val == 0) { + msg = "invalid checkpoint number 0"; + goto parse_error; + } + sd->cno = val; + return 0; + +parse_error: + nilfs_err(NULL, "invalid option \"%s\": %s", option, msg); + return 1; +} + +/** + * 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) + ret = nilfs_parse_snapshot_option(p, &args[0], + sd); + } + 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_dev = *(dev_t *)data; + return 0; +} + +static int nilfs_test_bdev_super(struct super_block *s, void *data) +{ + return !(s->s_iflags & SB_I_RETIRED) && s->s_dev == *(dev_t *)data; +} + +static struct dentry * +nilfs_mount(struct file_system_type *fs_type, int flags, + const char *dev_name, void *data) +{ + struct nilfs_super_data sd = { .flags = flags }; + struct super_block *s; + dev_t dev; + int err; + + if (nilfs_identify(data, &sd)) + return ERR_PTR(-EINVAL); + + err = lookup_bdev(dev_name, &dev); + if (err) + return ERR_PTR(err); + + s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags, + &dev); + if (IS_ERR(s)) + return ERR_CAST(s); + + if (!s->s_root) { + /* + * We drop s_umount here because we need to open the bdev and + * bdev->open_mutex ranks above s_umount (blkdev_put() -> + * __invalidate_device()). It is safe because we have active sb + * reference and SB_BORN is not set yet. + */ + up_write(&s->s_umount); + err = setup_bdev_super(s, flags, NULL); + down_write(&s->s_umount); + if (!err) + err = nilfs_fill_super(s, data, + flags & SB_SILENT ? 1 : 0); + if (err) + goto failed_super; + + s->s_flags |= SB_ACTIVE; + } else if (!sd.cno) { + if (nilfs_tree_is_busy(s->s_root)) { + if ((flags ^ s->s_flags) & SB_RDONLY) { + nilfs_err(s, + "the device already has a %s mount.", + sb_rdonly(s) ? "read-only" : "read/write"); + err = -EBUSY; + goto failed_super; + } + } else { + /* + * 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) { + struct dentry *root_dentry; + + err = nilfs_attach_snapshot(s, sd.cno, &root_dentry); + if (err) + goto failed_super; + return root_dentry; + } + + return dget(s->s_root); + + failed_super: + deactivate_locked_super(s); + return ERR_PTR(err); +} + +struct file_system_type nilfs_fs_type = { + .owner = THIS_MODULE, + .name = "nilfs2", + .mount = nilfs_mount, + .kill_sb = kill_block_super, + .fs_flags = FS_REQUIRES_DEV, +}; +MODULE_ALIAS_FS("nilfs2"); + +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 + 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) +{ + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); + + kmem_cache_destroy(nilfs_inode_cachep); + kmem_cache_destroy(nilfs_transaction_cachep); + kmem_cache_destroy(nilfs_segbuf_cachep); + 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|SLAB_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 = nilfs_sysfs_init(); + if (err) + goto free_cachep; + + err = register_filesystem(&nilfs_fs_type); + if (err) + goto deinit_sysfs_entry; + + printk(KERN_INFO "NILFS version 2 loaded\n"); + return 0; + +deinit_sysfs_entry: + nilfs_sysfs_exit(); +free_cachep: + nilfs_destroy_cachep(); +fail: + return err; +} + +static void __exit exit_nilfs_fs(void) +{ + nilfs_destroy_cachep(); + nilfs_sysfs_exit(); + unregister_filesystem(&nilfs_fs_type); +} + +module_init(init_nilfs_fs) +module_exit(exit_nilfs_fs) |