#include <linux/writeback.h>
#include <linux/kobject.h>
#include <linux/exportfs.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
#include "nilfs.h"
#include "mdt.h"
#include "alloc.h"
MODULE_AUTHOR("NTT Corp.");
MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
"(NILFS)");
-MODULE_VERSION(NILFS_VERSION);
MODULE_LICENSE("GPL");
static int nilfs_remount(struct super_block *sb, int *flags, char *data);
-static int test_exclusive_mount(struct file_system_type *fs_type,
- struct block_device *bdev, int flags);
/**
* nilfs_error() - report failure condition on a filesystem
down_write(&nilfs->ns_sem);
if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
nilfs->ns_mount_state |= NILFS_ERROR_FS;
- nilfs->ns_sbp->s_state |= cpu_to_le16(NILFS_ERROR_FS);
- nilfs_commit_super(sbi);
+ nilfs->ns_sbp[0]->s_state |=
+ cpu_to_le16(NILFS_ERROR_FS);
+ nilfs_commit_super(sbi, 1);
}
up_write(&nilfs->ns_sem);
static struct kmem_cache *nilfs_inode_cachep;
-struct inode *nilfs_alloc_inode(struct super_block *sb)
+struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs)
{
struct nilfs_inode_info *ii;
ii->i_bh = NULL;
ii->i_state = 0;
ii->vfs_inode.i_version = 1;
- nilfs_btnode_cache_init(&ii->i_btnode_cache);
+ 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)
{
kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
{
struct nilfs_inode_info *ii = NILFS_I(inode);
-#ifdef CONFIG_NILFS_POSIX_ACL
- if (ii->i_acl && ii->i_acl != NILFS_ACL_NOT_CACHED) {
- posix_acl_release(ii->i_acl);
- ii->i_acl = NILFS_ACL_NOT_CACHED;
- }
- if (ii->i_default_acl && ii->i_default_acl != NILFS_ACL_NOT_CACHED) {
- posix_acl_release(ii->i_default_acl);
- ii->i_default_acl = NILFS_ACL_NOT_CACHED;
- }
-#endif
/*
* Free resources allocated in nilfs_read_inode(), here.
*/
nilfs_btnode_cache_clear(&ii->i_btnode_cache);
}
-/**
- * nilfs_update_last_segment - change pointer to the latest segment
- * @sbi: nilfs_sb_info
- * @update_cno: flag whether to update checkpoint number.
- *
- * nilfs_update_last_segment() changes information in the super block
- * after a partial segment is written out successfully. The super
- * block is marked dirty. It will be written out at the next VFS sync
- * operations such as sync_supers() and generic_shutdown_super().
- */
-void nilfs_update_last_segment(struct nilfs_sb_info *sbi, int update_cno)
-{
- struct the_nilfs *nilfs = sbi->s_nilfs;
- struct nilfs_super_block *sbp = nilfs->ns_sbp;
-
- /* nilfs->sem must be locked by the caller. */
- spin_lock(&nilfs->ns_last_segment_lock);
- if (update_cno)
- nilfs->ns_last_cno = nilfs->ns_cno++;
- sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
- sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
- sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
- spin_unlock(&nilfs->ns_last_segment_lock);
-
- sbi->s_super->s_dirt = 1; /* must be set if delaying the call of
- nilfs_commit_super() */
-}
-
-static int nilfs_sync_super(struct nilfs_sb_info *sbi)
+static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
{
struct the_nilfs *nilfs = sbi->s_nilfs;
int err;
int barrier_done = 0;
if (nilfs_test_opt(sbi, BARRIER)) {
- set_buffer_ordered(nilfs->ns_sbh);
+ set_buffer_ordered(nilfs->ns_sbh[0]);
barrier_done = 1;
}
retry:
- set_buffer_dirty(nilfs->ns_sbh);
- err = sync_dirty_buffer(nilfs->ns_sbh);
+ set_buffer_dirty(nilfs->ns_sbh[0]);
+ err = sync_dirty_buffer(nilfs->ns_sbh[0]);
if (err == -EOPNOTSUPP && barrier_done) {
nilfs_warning(sbi->s_super, __func__,
"barrier-based sync failed. "
"disabling barriers\n");
nilfs_clear_opt(sbi, BARRIER);
barrier_done = 0;
- clear_buffer_ordered(nilfs->ns_sbh);
+ clear_buffer_ordered(nilfs->ns_sbh[0]);
goto retry;
}
- if (unlikely(err))
+ if (unlikely(err)) {
printk(KERN_ERR
"NILFS: unable to write superblock (err=%d)\n", err);
- else {
+ if (err == -EIO && nilfs->ns_sbh[1]) {
+ nilfs_fall_back_super_block(nilfs);
+ goto retry;
+ }
+ } else {
+ struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
+
+ /*
+ * The latest segment becomes trailable from the position
+ * written in superblock.
+ */
clear_nilfs_discontinued(nilfs);
- spin_lock(&nilfs->ns_last_segment_lock);
- nilfs->ns_prot_seq = le64_to_cpu(nilfs->ns_sbp->s_last_seq);
- spin_unlock(&nilfs->ns_last_segment_lock);
+
+ /* update GC protection for recent segments */
+ if (nilfs->ns_sbh[1]) {
+ sbp = NULL;
+ if (dupsb) {
+ set_buffer_dirty(nilfs->ns_sbh[1]);
+ if (!sync_dirty_buffer(nilfs->ns_sbh[1]))
+ sbp = nilfs->ns_sbp[1];
+ }
+ }
+ if (sbp) {
+ spin_lock(&nilfs->ns_last_segment_lock);
+ nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
+ spin_unlock(&nilfs->ns_last_segment_lock);
+ }
}
return err;
}
-int nilfs_commit_super(struct nilfs_sb_info *sbi)
+int nilfs_commit_super(struct nilfs_sb_info *sbi, int dupsb)
{
struct the_nilfs *nilfs = sbi->s_nilfs;
- struct nilfs_super_block *sbp = nilfs->ns_sbp;
+ struct nilfs_super_block **sbp = nilfs->ns_sbp;
sector_t nfreeblocks;
+ time_t t;
int err;
/* nilfs->sem must be locked by the caller. */
+ if (sbp[0]->s_magic != NILFS_SUPER_MAGIC) {
+ if (sbp[1] && sbp[1]->s_magic == NILFS_SUPER_MAGIC)
+ nilfs_swap_super_block(nilfs);
+ else {
+ printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
+ sbi->s_super->s_id);
+ return -EIO;
+ }
+ }
err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
if (unlikely(err)) {
printk(KERN_ERR "NILFS: failed to count free blocks\n");
return err;
}
- sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
- sbp->s_wtime = cpu_to_le64(get_seconds());
- sbp->s_sum = 0;
- sbp->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
- (unsigned char *)sbp,
- le16_to_cpu(sbp->s_bytes)));
+ spin_lock(&nilfs->ns_last_segment_lock);
+ sbp[0]->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
+ sbp[0]->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
+ sbp[0]->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
+ spin_unlock(&nilfs->ns_last_segment_lock);
+
+ t = get_seconds();
+ nilfs->ns_sbwtime[0] = t;
+ sbp[0]->s_free_blocks_count = cpu_to_le64(nfreeblocks);
+ sbp[0]->s_wtime = cpu_to_le64(t);
+ sbp[0]->s_sum = 0;
+ sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
+ (unsigned char *)sbp[0],
+ nilfs->ns_sbsize));
+ if (dupsb && sbp[1]) {
+ memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
+ nilfs->ns_sbwtime[1] = t;
+ }
sbi->s_super->s_dirt = 0;
- return nilfs_sync_super(sbi);
+ return nilfs_sync_super(sbi, dupsb);
}
static void nilfs_put_super(struct super_block *sb)
struct nilfs_sb_info *sbi = NILFS_SB(sb);
struct the_nilfs *nilfs = sbi->s_nilfs;
+ lock_kernel();
+
nilfs_detach_segment_constructor(sbi);
if (!(sb->s_flags & MS_RDONLY)) {
down_write(&nilfs->ns_sem);
- nilfs->ns_sbp->s_state = cpu_to_le16(nilfs->ns_mount_state);
- nilfs_commit_super(sbi);
+ nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
+ nilfs_commit_super(sbi, 1);
up_write(&nilfs->ns_sem);
}
+ down_write(&nilfs->ns_super_sem);
+ if (nilfs->ns_current == sbi)
+ nilfs->ns_current = NULL;
+ up_write(&nilfs->ns_super_sem);
nilfs_detach_checkpoint(sbi);
put_nilfs(sbi->s_nilfs);
sbi->s_super = NULL;
sb->s_fs_info = NULL;
- kfree(sbi);
-}
+ nilfs_put_sbinfo(sbi);
-/**
- * nilfs_write_super - write super block(s) of NILFS
- * @sb: super_block
- *
- * nilfs_write_super() gets a fs-dependent lock, writes super block(s), and
- * clears s_dirt. This function is called in the section protected by
- * lock_super().
- *
- * The s_dirt flag is managed by each filesystem and we protect it by ns_sem
- * of the struct the_nilfs. Lock order must be as follows:
- *
- * 1. lock_super()
- * 2. down_write(&nilfs->ns_sem)
- *
- * Inside NILFS, locking ns_sem is enough to protect s_dirt and the buffer
- * of the super block (nilfs->ns_sbp).
- *
- * In most cases, VFS functions call lock_super() before calling these
- * methods. So we must be careful not to bring on deadlocks when using
- * lock_super(); see generic_shutdown_super(), write_super(), and so on.
- *
- * Note that order of lock_kernel() and lock_super() depends on contexts
- * of VFS. We should also note that lock_kernel() can be used in its
- * protective section and only the outermost one has an effect.
- */
-static void nilfs_write_super(struct super_block *sb)
-{
- struct nilfs_sb_info *sbi = NILFS_SB(sb);
- struct the_nilfs *nilfs = sbi->s_nilfs;
-
- down_write(&nilfs->ns_sem);
- if (!(sb->s_flags & MS_RDONLY))
- nilfs_commit_super(sbi);
- sb->s_dirt = 0;
- up_write(&nilfs->ns_sem);
+ unlock_kernel();
}
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;
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 (sb->s_dirt)
+ nilfs_commit_super(sbi, 1);
+ up_write(&nilfs->ns_sem);
+
return err;
}
struct buffer_head *bh_cp;
int err;
- down_write(&nilfs->ns_sem);
+ down_write(&nilfs->ns_super_sem);
list_add(&sbi->s_list, &nilfs->ns_supers);
- up_write(&nilfs->ns_sem);
+ up_write(&nilfs->ns_super_sem);
- sbi->s_ifile = nilfs_mdt_new(
- nilfs, sbi->s_super, NILFS_IFILE_INO, NILFS_IFILE_GFP);
+ sbi->s_ifile = nilfs_mdt_new(nilfs, sbi->s_super, NILFS_IFILE_INO);
if (!sbi->s_ifile)
return -ENOMEM;
if (unlikely(err))
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_mdt_destroy(sbi->s_ifile);
sbi->s_ifile = NULL;
- down_write(&nilfs->ns_sem);
+ down_write(&nilfs->ns_super_sem);
list_del_init(&sbi->s_list);
- up_write(&nilfs->ns_sem);
+ up_write(&nilfs->ns_super_sem);
return err;
}
nilfs_mdt_clear(sbi->s_ifile);
nilfs_mdt_destroy(sbi->s_ifile);
sbi->s_ifile = NULL;
- down_write(&nilfs->ns_sem);
+ down_write(&nilfs->ns_super_sem);
list_del_init(&sbi->s_list);
- up_write(&nilfs->ns_sem);
+ up_write(&nilfs->ns_super_sem);
}
static int nilfs_mark_recovery_complete(struct nilfs_sb_info *sbi)
down_write(&nilfs->ns_sem);
if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) {
nilfs->ns_mount_state |= NILFS_VALID_FS;
- err = nilfs_commit_super(sbi);
+ err = nilfs_commit_super(sbi, 1);
if (likely(!err))
printk(KERN_INFO "NILFS: recovery complete.\n");
}
{
struct super_block *sb = dentry->d_sb;
struct nilfs_sb_info *sbi = NILFS_SB(sb);
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
unsigned long long blocks;
unsigned long overhead;
unsigned long nrsvblocks;
sector_t nfreeblocks;
- struct the_nilfs *nilfs = sbi->s_nilfs;
int err;
/*
buf->f_files = atomic_read(&sbi->s_inodes_count);
buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
buf->f_namelen = NILFS_NAME_LEN;
+ buf->f_fsid.val[0] = (u32)id;
+ buf->f_fsid.val[1] = (u32)(id >> 32);
+
+ return 0;
+}
+
+static 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);
+
+ if (!nilfs_test_opt(sbi, BARRIER))
+ seq_printf(seq, ",barrier=off");
+ if (nilfs_test_opt(sbi, SNAPSHOT))
+ seq_printf(seq, ",cp=%llu",
+ (unsigned long long int)sbi->s_snapshot_cno);
+ if (nilfs_test_opt(sbi, ERRORS_RO))
+ seq_printf(seq, ",errors=remount-ro");
+ if (nilfs_test_opt(sbi, ERRORS_PANIC))
+ seq_printf(seq, ",errors=panic");
+ if (nilfs_test_opt(sbi, STRICT_ORDER))
+ seq_printf(seq, ",order=strict");
+
return 0;
}
-static struct super_operations nilfs_sops = {
+static const struct super_operations nilfs_sops = {
.alloc_inode = nilfs_alloc_inode,
.destroy_inode = nilfs_destroy_inode,
.dirty_inode = nilfs_dirty_inode,
/* .drop_inode = nilfs_drop_inode, */
.delete_inode = nilfs_delete_inode,
.put_super = nilfs_put_super,
- .write_super = nilfs_write_super,
+ /* .write_super = nilfs_write_super, */
.sync_fs = nilfs_sync_fs,
/* .write_super_lockfs */
/* .unlockfs */
.remount_fs = nilfs_remount,
.clear_inode = nilfs_clear_inode,
/* .umount_begin */
- /* .show_options */
+ .show_options = nilfs_show_options
};
static struct inode *
nilfs_nfs_get_inode);
}
-static struct export_operations nilfs_export_ops = {
+static const struct export_operations nilfs_export_ops = {
.fh_to_dentry = nilfs_fh_to_dentry,
.fh_to_parent = nilfs_fh_to_parent,
.get_parent = nilfs_get_parent,
static int nilfs_setup_super(struct nilfs_sb_info *sbi)
{
struct the_nilfs *nilfs = sbi->s_nilfs;
- struct nilfs_super_block *sbp = nilfs->ns_sbp;
+ struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
int max_mnt_count = le16_to_cpu(sbp->s_max_mnt_count);
int mnt_count = le16_to_cpu(sbp->s_mnt_count);
sbp->s_mnt_count = cpu_to_le16(mnt_count + 1);
sbp->s_state = cpu_to_le16(le16_to_cpu(sbp->s_state) & ~NILFS_VALID_FS);
sbp->s_mtime = cpu_to_le64(get_seconds());
- return nilfs_commit_super(sbi);
+ return nilfs_commit_super(sbi, 1);
}
-struct nilfs_super_block *
-nilfs_load_super_block(struct super_block *sb, struct buffer_head **pbh)
+struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
+ u64 pos, int blocksize,
+ struct buffer_head **pbh)
{
- int blocksize;
- unsigned long offset, sb_index;
-
- /*
- * Adjusting block size
- * Blocksize will be enlarged when it is smaller than hardware
- * sector size.
- * Disk format of superblock does not change.
- */
- blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
- if (!blocksize) {
- printk(KERN_ERR
- "NILFS: unable to set blocksize of superblock\n");
- return NULL;
- }
- sb_index = NILFS_SB_OFFSET_BYTES / blocksize;
- offset = NILFS_SB_OFFSET_BYTES % blocksize;
+ unsigned long long sb_index = pos;
+ unsigned long offset;
+ offset = do_div(sb_index, blocksize);
*pbh = sb_bread(sb, sb_index);
- if (!*pbh) {
- printk(KERN_ERR "NILFS: unable to read superblock\n");
+ if (!*pbh)
return NULL;
- }
return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
}
-struct nilfs_super_block *
-nilfs_reload_super_block(struct super_block *sb, struct buffer_head **pbh,
- int blocksize)
-{
- struct nilfs_super_block *sbp;
- unsigned long offset, sb_index;
- int hw_blocksize = bdev_hardsect_size(sb->s_bdev);
-
- if (blocksize < hw_blocksize) {
- printk(KERN_ERR
- "NILFS: blocksize %d too small for device "
- "(sector-size = %d).\n",
- blocksize, hw_blocksize);
- goto failed_sbh;
- }
- brelse(*pbh);
- sb_set_blocksize(sb, blocksize);
-
- sb_index = NILFS_SB_OFFSET_BYTES / blocksize;
- offset = NILFS_SB_OFFSET_BYTES % blocksize;
-
- *pbh = sb_bread(sb, sb_index);
- if (!*pbh) {
- printk(KERN_ERR
- "NILFS: cannot read superblock on 2nd try.\n");
- goto failed;
- }
-
- sbp = (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
- if (sbp->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
- printk(KERN_ERR
- "NILFS: !? Magic mismatch on 2nd try.\n");
- goto failed_sbh;
- }
- return sbp;
-
- failed_sbh:
- brelse(*pbh);
-
- failed:
- return NULL;
-}
-
int nilfs_store_magic_and_option(struct super_block *sb,
struct nilfs_super_block *sbp,
char *data)
{
struct nilfs_sb_info *sbi = NILFS_SB(sb);
- /* trying to fill super (1st stage) */
sb->s_magic = le16_to_cpu(sbp->s_magic);
/* FS independent flags */
sb->s_flags |= MS_NOATIME;
#endif
- if (sb->s_magic != NILFS_SUPER_MAGIC) {
- printk("NILFS: Can't find nilfs on dev %s.\n", sb->s_id);
- return -EINVAL;
- }
-
nilfs_set_default_options(sbi, sbp);
sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
- if (!parse_options(data, sb))
- return -EINVAL;
-
- return 0;
+ return !parse_options(data, sb) ? -EINVAL : 0 ;
}
/**
* @silent: silent mode flag
* @nilfs: the_nilfs struct
*
- * This function is called exclusively by bd_mount_mutex.
+ * This function is called exclusively by nilfs->ns_mount_mutex.
* So, the recovery process is protected from other simultaneous mounts.
*/
static int
get_nilfs(nilfs);
sbi->s_nilfs = nilfs;
sbi->s_super = sb;
+ atomic_set(&sbi->s_count, 1);
err = init_nilfs(nilfs, sbi, (char *)data);
if (err)
sb->s_op = &nilfs_sops;
sb->s_export_op = &nilfs_export_ops;
sb->s_root = NULL;
+ sb->s_time_gran = 1;
if (!nilfs_loaded(nilfs)) {
err = load_nilfs(nilfs, sbi);
if (sb->s_flags & MS_RDONLY) {
if (nilfs_test_opt(sbi, SNAPSHOT)) {
+ down_read(&nilfs->ns_segctor_sem);
err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile,
sbi->s_snapshot_cno);
- if (err < 0)
+ up_read(&nilfs->ns_segctor_sem);
+ if (err < 0) {
+ if (err == -ENOENT)
+ err = -EINVAL;
goto failed_sbi;
+ }
if (!err) {
printk(KERN_ERR
"NILFS: The specified checkpoint is "
goto failed_root;
}
+ down_write(&nilfs->ns_super_sem);
+ if (!nilfs_test_opt(sbi, SNAPSHOT))
+ nilfs->ns_current = sbi;
+ up_write(&nilfs->ns_super_sem);
+
return 0;
failed_root:
failed_sbi:
put_nilfs(nilfs);
sb->s_fs_info = NULL;
- kfree(sbi);
+ nilfs_put_sbinfo(sbi);
return err;
}
struct nilfs_mount_options old_opts;
int err;
+ lock_kernel();
+
+ down_write(&nilfs->ns_super_sem);
old_sb_flags = sb->s_flags;
old_opts.mount_opt = sbi->s_mount_opt;
old_opts.snapshot_cno = sbi->s_snapshot_cno;
* the RDONLY flag and then mark the partition as valid again.
*/
down_write(&nilfs->ns_sem);
- sbp = nilfs->ns_sbp;
+ sbp = nilfs->ns_sbp[0];
if (!(sbp->s_state & le16_to_cpu(NILFS_VALID_FS)) &&
(nilfs->ns_mount_state & NILFS_VALID_FS))
sbp->s_state = cpu_to_le16(nilfs->ns_mount_state);
sbp->s_mtime = cpu_to_le64(get_seconds());
- nilfs_commit_super(sbi);
+ nilfs_commit_super(sbi, 1);
up_write(&nilfs->ns_sem);
} else {
/*
* store the current valid flag. (It may have been changed
* by fsck since we originally mounted the partition.)
*/
- down(&sb->s_bdev->bd_mount_sem);
- /* Check existing RW-mount */
- if (test_exclusive_mount(sb->s_type, sb->s_bdev, 0)) {
+ if (nilfs->ns_current && nilfs->ns_current != sbi) {
printk(KERN_WARNING "NILFS (device %s): couldn't "
- "remount because a RW-mount exists.\n",
+ "remount because an RW-mount exists.\n",
sb->s_id);
err = -EBUSY;
- goto rw_remount_failed;
+ goto restore_opts;
}
if (sbi->s_snapshot_cno != nilfs_last_cno(nilfs)) {
printk(KERN_WARNING "NILFS (device %s): couldn't "
"the latest one.\n",
sb->s_id);
err = -EINVAL;
- goto rw_remount_failed;
+ goto restore_opts;
}
sb->s_flags &= ~MS_RDONLY;
nilfs_clear_opt(sbi, SNAPSHOT);
err = nilfs_attach_segment_constructor(sbi);
if (err)
- goto rw_remount_failed;
+ goto restore_opts;
down_write(&nilfs->ns_sem);
nilfs_setup_super(sbi);
up_write(&nilfs->ns_sem);
- up(&sb->s_bdev->bd_mount_sem);
+ nilfs->ns_current = sbi;
}
out:
+ up_write(&nilfs->ns_super_sem);
+ unlock_kernel();
return 0;
- rw_remount_failed:
- up(&sb->s_bdev->bd_mount_sem);
restore_opts:
sb->s_flags = old_sb_flags;
sbi->s_mount_opt = old_opts.mount_opt;
sbi->s_snapshot_cno = old_opts.snapshot_cno;
+ up_write(&nilfs->ns_super_sem);
+ unlock_kernel();
return err;
}
struct nilfs_super_data {
struct block_device *bdev;
+ struct nilfs_sb_info *sbi;
__u64 cno;
int flags;
};
{
struct nilfs_super_data *sd = data;
- return s->s_bdev == sd->bdev;
-}
-
-static int nilfs_test_bdev_super2(struct super_block *s, void *data)
-{
- struct nilfs_super_data *sd = data;
- int ret;
-
- if (s->s_bdev != sd->bdev)
- return 0;
-
- if (!((s->s_flags | sd->flags) & MS_RDONLY))
- return 1; /* Reuse an old R/W-mode super_block */
-
- if (s->s_flags & sd->flags & MS_RDONLY) {
- if (down_read_trylock(&s->s_umount)) {
- ret = s->s_root &&
- (sd->cno == NILFS_SB(s)->s_snapshot_cno);
- up_read(&s->s_umount);
- /*
- * This path is locked with sb_lock by sget().
- * So, drop_super() causes deadlock.
- */
- return ret;
- }
- }
- return 0;
+ return sd->sbi && s->s_fs_info == (void *)sd->sbi;
}
static int
const char *dev_name, void *data, struct vfsmount *mnt)
{
struct nilfs_super_data sd;
- struct super_block *s, *s2;
- struct the_nilfs *nilfs = NULL;
+ struct super_block *s;
+ struct the_nilfs *nilfs;
int err, need_to_close = 1;
sd.bdev = open_bdev_exclusive(dev_name, flags, fs_type);
* much more information than normal filesystems to identify mount
* instance. For snapshot mounts, not only a mount type (ro-mount
* or rw-mount) but also a checkpoint number is required.
- * The results are passed in sget() using nilfs_super_data.
*/
sd.cno = 0;
sd.flags = flags;
goto failed;
}
- /*
- * once the super is inserted into the list by sget, s_umount
- * will protect the lockfs code from trying to start a snapshot
- * while we are mounting
- */
- down(&sd.bdev->bd_mount_sem);
- if (!sd.cno &&
- (err = test_exclusive_mount(fs_type, sd.bdev, flags ^ MS_RDONLY))) {
- err = (err < 0) ? : -EBUSY;
- goto failed_unlock;
+ nilfs = find_or_create_nilfs(sd.bdev);
+ if (!nilfs) {
+ err = -ENOMEM;
+ goto failed;
}
- /*
- * Phase-1: search any existent instance and get the_nilfs
- */
- s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
- if (IS_ERR(s))
- goto error_s;
-
- if (!s->s_root) {
- err = -ENOMEM;
- nilfs = alloc_nilfs(sd.bdev);
- if (!nilfs)
- goto cancel_new;
- } else {
- struct nilfs_sb_info *sbi = NILFS_SB(s);
+ mutex_lock(&nilfs->ns_mount_mutex);
+ if (!sd.cno) {
/*
- * s_umount protects super_block from unmount process;
- * It covers pointers of nilfs_sb_info and the_nilfs.
+ * Check if an exclusive mount exists or not.
+ * Snapshot mounts coexist with a current mount
+ * (i.e. rw-mount or ro-mount), whereas rw-mount and
+ * ro-mount are mutually exclusive.
*/
- nilfs = sbi->s_nilfs;
- get_nilfs(nilfs);
- up_write(&s->s_umount);
+ down_read(&nilfs->ns_super_sem);
+ if (nilfs->ns_current &&
+ ((nilfs->ns_current->s_super->s_flags ^ flags)
+ & MS_RDONLY)) {
+ up_read(&nilfs->ns_super_sem);
+ err = -EBUSY;
+ goto failed_unlock;
+ }
+ up_read(&nilfs->ns_super_sem);
+ }
- /*
- * Phase-2: search specified snapshot or R/W mode super_block
- */
- if (!sd.cno)
- /* trying to get the latest checkpoint. */
- sd.cno = nilfs_last_cno(nilfs);
+ /*
+ * Find existing nilfs_sb_info struct
+ */
+ sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno);
- s2 = sget(fs_type, nilfs_test_bdev_super2,
- nilfs_set_bdev_super, &sd);
- deactivate_super(s);
- /*
- * Although deactivate_super() invokes close_bdev_exclusive() at
- * kill_block_super(). Here, s is an existent mount; we need
- * one more close_bdev_exclusive() call.
- */
- s = s2;
- if (IS_ERR(s))
- goto error_s;
+ /*
+ * Get super block instance holding the nilfs_sb_info struct.
+ * A new instance is allocated if no existing mount is present or
+ * existing instance has been unmounted.
+ */
+ s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
+ if (sd.sbi)
+ nilfs_put_sbinfo(sd.sbi);
+
+ if (IS_ERR(s)) {
+ err = PTR_ERR(s);
+ goto failed_unlock;
}
if (!s->s_root) {
char b[BDEVNAME_SIZE];
+ /* New superblock instance created */
s->s_flags = flags;
strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
sb_set_blocksize(s, block_size(sd.bdev));
s->s_flags |= MS_ACTIVE;
need_to_close = 0;
- } else if (!(s->s_flags & MS_RDONLY)) {
- err = -EBUSY;
}
- up(&sd.bdev->bd_mount_sem);
+ mutex_unlock(&nilfs->ns_mount_mutex);
put_nilfs(nilfs);
if (need_to_close)
close_bdev_exclusive(sd.bdev, flags);
simple_set_mnt(mnt, s);
return 0;
- error_s:
- up(&sd.bdev->bd_mount_sem);
- if (nilfs)
- put_nilfs(nilfs);
- close_bdev_exclusive(sd.bdev, flags);
- return PTR_ERR(s);
-
failed_unlock:
- up(&sd.bdev->bd_mount_sem);
+ mutex_unlock(&nilfs->ns_mount_mutex);
+ put_nilfs(nilfs);
failed:
close_bdev_exclusive(sd.bdev, flags);
cancel_new:
/* Abandoning the newly allocated superblock */
- up(&sd.bdev->bd_mount_sem);
- if (nilfs)
- put_nilfs(nilfs);
+ mutex_unlock(&nilfs->ns_mount_mutex);
+ put_nilfs(nilfs);
up_write(&s->s_umount);
deactivate_super(s);
/*
* deactivate_super() invokes close_bdev_exclusive().
* We must finish all post-cleaning before this call;
- * put_nilfs() and unlocking bd_mount_sem need the block device.
+ * put_nilfs() needs the block device.
*/
return err;
}
-static int nilfs_test_bdev_super3(struct super_block *s, void *data)
-{
- struct nilfs_super_data *sd = data;
- int ret;
-
- if (s->s_bdev != sd->bdev)
- return 0;
- if (down_read_trylock(&s->s_umount)) {
- ret = (s->s_flags & MS_RDONLY) && s->s_root &&
- nilfs_test_opt(NILFS_SB(s), SNAPSHOT);
- up_read(&s->s_umount);
- if (ret)
- return 0; /* ignore snapshot mounts */
- }
- return !((sd->flags ^ s->s_flags) & MS_RDONLY);
-}
-
-static int __false_bdev_super(struct super_block *s, void *data)
-{
-#if 0 /* XXX: workaround for lock debug. This is not good idea */
- up_write(&s->s_umount);
-#endif
- return -EFAULT;
-}
-
-/**
- * test_exclusive_mount - check whether an exclusive RW/RO mount exists or not.
- * fs_type: filesystem type
- * bdev: block device
- * flag: 0 (check rw-mount) or MS_RDONLY (check ro-mount)
- * res: pointer to an integer to store result
- *
- * This function must be called within a section protected by bd_mount_mutex.
- */
-static int test_exclusive_mount(struct file_system_type *fs_type,
- struct block_device *bdev, int flags)
-{
- struct super_block *s;
- struct nilfs_super_data sd = { .flags = flags, .bdev = bdev };
-
- s = sget(fs_type, nilfs_test_bdev_super3, __false_bdev_super, &sd);
- if (IS_ERR(s)) {
- if (PTR_ERR(s) != -EFAULT)
- return PTR_ERR(s);
- return 0; /* Not found */
- }
- up_write(&s->s_umount);
- deactivate_super(s);
- return 1; /* Found */
-}
-
struct file_system_type nilfs_fs_type = {
.owner = THIS_MODULE,
.name = "nilfs2",
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff