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 <konishi.ryusuke@lab.ntt.co.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 1c505d0..3c9833e 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -1061,13 +1061,6 @@
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;
if (s->s_bdev != sd->bdev)
@@ -1096,8 +1089,8 @@
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 @@
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 @@
}
/*
- * Phase-1: search any existent instance and get the_nilfs
+ * Search specified snapshot or R/W mode super_block
*/
+ if (!sd.cno)
+ /* trying to get the latest checkpoint. */
+ sd.cno = nilfs_last_cno(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);
-
- /*
- * 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;
+ 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 @@
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 @@
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);
/*