From 33c8e57c86d1bd1548c12a4f7c4bceb94b862cca Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Mon, 8 Jun 2009 01:39:29 +0900 Subject: nilfs2: get rid of sget use for acquiring nilfs object This will change the way to obtain nilfs object in nilfs_get_sb() function. Previously, a preliminary sget() call was performed, and the nilfs object was acquired from a super block instance found by the sget() call. This patch, instead, instroduces a new dedicated function find_or_create_nilfs(); as the name implies, the function finds an existent nilfs object from a global list or creates a new one if no object is found on the device. Signed-off-by: Ryusuke Konishi Cc: Al Viro Signed-off-by: Al Viro --- fs/nilfs2/super.c | 80 +++++++++++++------------------------------------------ 1 file changed, 19 insertions(+), 61 deletions(-) (limited to 'fs/nilfs2/super.c') diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index 1c505d0e031..3c9833e3e74 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -1059,13 +1059,6 @@ 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; - - 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; @@ -1096,8 +1089,8 @@ 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, *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); @@ -1118,11 +1111,12 @@ nilfs_get_sb(struct file_system_type *fs_type, int 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 - */ + nilfs = find_or_create_nilfs(sd.bdev); + if (!nilfs) { + err = -ENOMEM; + goto failed; + } + down(&sd.bdev->bd_mount_sem); if (!sd.cno && (err = test_exclusive_mount(fs_type, sd.bdev, flags ^ MS_RDONLY))) { @@ -1131,51 +1125,22 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags, } /* - * Phase-1: search any existent instance and get the_nilfs + * Search specified snapshot or R/W mode super_block */ - 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); + if (!sd.cno) + /* trying to get the latest checkpoint. */ + sd.cno = nilfs_last_cno(nilfs); - /* - * s_umount protects super_block from unmount process; - * It covers pointers of nilfs_sb_info and the_nilfs. - */ - nilfs = sbi->s_nilfs; - get_nilfs(nilfs); - up_write(&s->s_umount); - - /* - * 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); - - 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; + s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd); + 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)); @@ -1195,15 +1160,9 @@ nilfs_get_sb(struct file_system_type *fs_type, int 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); + put_nilfs(nilfs); failed: close_bdev_exclusive(sd.bdev, flags); @@ -1212,8 +1171,7 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags, cancel_new: /* Abandoning the newly allocated superblock */ up(&sd.bdev->bd_mount_sem); - if (nilfs) - put_nilfs(nilfs); + put_nilfs(nilfs); up_write(&s->s_umount); deactivate_super(s); /* -- cgit v1.2.3