After applied the patch that unified sb instances, root dentry of
snapshots can be left in dcache even after their trees are unmounted.
The orphan root dentry/inode keeps a root object, and this causes
false positive of nilfs_checkpoint_is_mounted function.
This resolves the issue by having nilfs_checkpoint_is_mounted test
whether the root dentry is busy or not.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxxxxxx>
---
fs/nilfs2/cpfile.c | 23 ++++++++---------------
fs/nilfs2/inode.c | 10 ++++++++++
fs/nilfs2/nilfs.h | 3 +++
fs/nilfs2/super.c | 32 ++++++++++++++++++++++++++++++++
fs/nilfs2/the_nilfs.c | 21 ---------------------
fs/nilfs2/the_nilfs.h | 1 -
6 files changed, 53 insertions(+), 37 deletions(-)
diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c
index 03de1da..5ff15a8 100644
--- a/fs/nilfs2/cpfile.c
+++ b/fs/nilfs2/cpfile.c
@@ -863,26 +863,19 @@ int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno)
*/
int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode)
{
- struct the_nilfs *nilfs;
int ret;
- nilfs = NILFS_MDT(cpfile)->mi_nilfs;
-
switch (mode) {
case NILFS_CHECKPOINT:
- /*
- * Check for protecting existing snapshot mounts:
- * ns_mount_mutex is used to make this operation atomic and
- * exclusive with a new mount job. Though it doesn't cover
- * umount, it's enough for the purpose.
- */
- if (nilfs_checkpoint_is_mounted(nilfs, cno, 1)) {
- /* Current implementation does not have to protect
- plain read-only mounts since they are exclusive
- with a read/write mount and are protected from the
- cleaner. */
+ if (nilfs_checkpoint_is_mounted(cpfile->i_sb, cno))
+ /*
+ * Current implementation does not have to protect
+ * plain read-only mounts since they are exclusive
+ * with a read/write mount and are protected from the
+ * cleaner.
+ */
ret = -EBUSY;
- } else
+ else
ret = nilfs_cpfile_clear_snapshot(cpfile, cno);
return ret;
case NILFS_SNAPSHOT:
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 5b3d43f..71d4bc8 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -506,6 +506,16 @@ static int nilfs_iget_set(struct inode *inode, void *opaque)
return 0;
}
+struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
+ unsigned long ino)
+{
+ struct nilfs_iget_args args = {
+ .ino = ino, .root = root, .cno = 0, .for_gc = 0
+ };
+
+ return ilookup5(sb, ino, nilfs_iget_test, &args);
+}
+
struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
unsigned long ino)
{
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index 2ca2ca5..f6e276e 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -244,6 +244,8 @@ extern int nilfs_get_block(struct inode *, sector_t, struct buffer_head *, int);
extern void nilfs_set_inode_flags(struct inode *);
extern int nilfs_read_inode_common(struct inode *, struct nilfs_inode *);
extern void nilfs_write_inode_common(struct inode *, struct nilfs_inode *, int);
+struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
+ unsigned long ino);
struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
unsigned long ino);
struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
@@ -285,6 +287,7 @@ extern int nilfs_commit_super(struct nilfs_sb_info *, int);
extern int nilfs_cleanup_super(struct nilfs_sb_info *);
int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
struct nilfs_root **root);
+int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno);
/* gcinode.c */
int nilfs_gccache_submit_read_data(struct inode *, sector_t, sector_t, __u64,
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 361400b..c0ce90b 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -838,6 +838,38 @@ static int nilfs_try_to_shrink_tree(struct dentry *root_dentry)
return nilfs_tree_was_touched(root_dentry);
}
+int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
+{
+ struct the_nilfs *nilfs = NILFS_SB(sb)->s_nilfs;
+ struct nilfs_root *root;
+ struct inode *inode;
+ struct dentry *dentry;
+ int ret;
+
+ if (cno < 0 || cno > nilfs->ns_cno)
+ return false;
+
+ if (cno >= nilfs_last_cno(nilfs))
+ return true; /* protect recent checkpoints */
+
+ ret = false;
+ root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs, cno);
+ if (root) {
+ inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
+ if (inode) {
+ dentry = d_find_alias(inode);
+ if (dentry) {
+ if (nilfs_tree_was_touched(dentry))
+ ret = nilfs_try_to_shrink_tree(dentry);
+ dput(dentry);
+ }
+ iput(inode);
+ }
+ nilfs_put_root(root);
+ }
+ return ret;
+}
+
/**
* nilfs_fill_super() - initialize a super block instance
* @sb: super_block
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 768e162..f973333 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -769,24 +769,3 @@ void nilfs_put_root(struct nilfs_root *root)
kfree(root);
}
}
-
-int nilfs_checkpoint_is_mounted(struct the_nilfs *nilfs, __u64 cno,
- int snapshot_mount)
-{
- struct nilfs_root *root;
- int ret;
-
- if (cno < 0 || cno > nilfs->ns_cno)
- return false;
-
- if (cno >= nilfs_last_cno(nilfs))
- return true; /* protect recent checkpoints */
-
- ret = false;
- root = nilfs_lookup_root(nilfs, cno);
- if (root) {
- ret = true;
- nilfs_put_root(root);
- }
- return ret;
-}
diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index a5178dc..cae56f3 100644
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -242,7 +242,6 @@ struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs,
__u64 cno);
void nilfs_put_root(struct nilfs_root *root);
struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *, int, __u64);
-int nilfs_checkpoint_is_mounted(struct the_nilfs *, __u64, int);
int nilfs_near_disk_full(struct the_nilfs *);
void nilfs_fall_back_super_block(struct the_nilfs *);
void nilfs_swap_super_block(struct the_nilfs *);
--
1.6.6.2
--
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