git simplify nilfs check for busy subtree

Reviewed-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2013-08-24 12:06:16 -04:00
parent 0507c78ae8
commit e95c311e17
1 changed files with 7 additions and 19 deletions

View File

@ -994,23 +994,16 @@ static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
return ret; return ret;
} }
static int nilfs_tree_was_touched(struct dentry *root_dentry)
{
return d_count(root_dentry) > 1;
}
/** /**
* nilfs_try_to_shrink_tree() - try to shrink dentries of a checkpoint * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint
* @root_dentry: root dentry of the tree to be shrunk * @root_dentry: root dentry of the tree to be shrunk
* *
* This function returns true if the tree was in-use. * This function returns true if the tree was in-use.
*/ */
static int nilfs_try_to_shrink_tree(struct dentry *root_dentry) static bool nilfs_tree_is_busy(struct dentry *root_dentry)
{ {
if (have_submounts(root_dentry))
return true;
shrink_dcache_parent(root_dentry); shrink_dcache_parent(root_dentry);
return nilfs_tree_was_touched(root_dentry); return d_count(root_dentry) > 1;
} }
int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno) int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
@ -1034,8 +1027,7 @@ int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
if (inode) { if (inode) {
dentry = d_find_alias(inode); dentry = d_find_alias(inode);
if (dentry) { if (dentry) {
if (nilfs_tree_was_touched(dentry)) ret = nilfs_tree_is_busy(dentry);
ret = nilfs_try_to_shrink_tree(dentry);
dput(dentry); dput(dentry);
} }
iput(inode); iput(inode);
@ -1331,11 +1323,8 @@ nilfs_mount(struct file_system_type *fs_type, int flags,
s->s_flags |= MS_ACTIVE; s->s_flags |= MS_ACTIVE;
} else if (!sd.cno) { } else if (!sd.cno) {
int busy = false; if (nilfs_tree_is_busy(s->s_root)) {
if ((flags ^ s->s_flags) & MS_RDONLY) {
if (nilfs_tree_was_touched(s->s_root)) {
busy = nilfs_try_to_shrink_tree(s->s_root);
if (busy && (flags ^ s->s_flags) & MS_RDONLY) {
printk(KERN_ERR "NILFS: the device already " printk(KERN_ERR "NILFS: the device already "
"has a %s mount.\n", "has a %s mount.\n",
(s->s_flags & MS_RDONLY) ? (s->s_flags & MS_RDONLY) ?
@ -1343,8 +1332,7 @@ nilfs_mount(struct file_system_type *fs_type, int flags,
err = -EBUSY; err = -EBUSY;
goto failed_super; goto failed_super;
} }
} } else {
if (!busy) {
/* /*
* Try remount to setup mount states if the current * Try remount to setup mount states if the current
* tree is not mounted and only snapshots use this sb. * tree is not mounted and only snapshots use this sb.