From 6dd4740662405a68bb229ac2b9e0aeaaf2188bf2 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Mon, 8 Jun 2009 01:39:31 +0900 Subject: nilfs2: simplify remaining sget() use This simplifies the test function passed on the remaining sget() callsite in nilfs. Instead of checking mount type (i.e. ro-mount/rw-mount/snapshot mount) in the test function passed to sget(), this patch first looks up the nilfs_sb_info struct which the given mount type matches, and then acquires the super block instance holding the nilfs_sb_info. Signed-off-by: Ryusuke Konishi Cc: Al Viro Signed-off-by: Al Viro --- fs/nilfs2/super.c | 42 +++++++++++++++++------------------------- 1 file changed, 17 insertions(+), 25 deletions(-) (limited to 'fs/nilfs2/super.c') diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index 5a8c5e4731b3..1d1b6e125159 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -336,7 +336,7 @@ static void nilfs_put_super(struct super_block *sb) put_nilfs(sbi->s_nilfs); sbi->s_super = NULL; sb->s_fs_info = NULL; - kfree(sbi); + nilfs_put_sbinfo(sbi); unlock_kernel(); } @@ -785,6 +785,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent, 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) @@ -902,7 +903,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent, failed_sbi: put_nilfs(nilfs); sb->s_fs_info = NULL; - kfree(sbi); + nilfs_put_sbinfo(sbi); return err; } @@ -1014,6 +1015,7 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data) struct nilfs_super_data { struct block_device *bdev; + struct nilfs_sb_info *sbi; __u64 cno; int flags; }; @@ -1071,27 +1073,8 @@ static int nilfs_set_bdev_super(struct super_block *s, void *data) static int nilfs_test_bdev_super(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 @@ -1112,7 +1095,6 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags, * 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; @@ -1148,13 +1130,23 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags, } /* - * Search specified snapshot or R/W mode super_block + * Find existing nilfs_sb_info struct */ + sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno); + if (!sd.cno) /* trying to get the latest checkpoint. */ sd.cno = nilfs_last_cno(nilfs); + /* + * 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; -- cgit v1.2.3