From: Erez Zadok <[email protected]>
Properly increase/release lower vfsmounts.
Validate proper use of unionfs mntget/put.
Signed-off-by: Erez Zadok <[email protected]>
Signed-off-by: Josef 'Jeff' Sipek <[email protected]>
---
fs/unionfs/dentry.c | 6 ++++--
fs/unionfs/inode.c | 11 +++++++++++
fs/unionfs/lookup.c | 11 ++++++-----
fs/unionfs/union.h | 47 +++++++++++++++++++++++++++++++++++++++--------
4 files changed, 60 insertions(+), 15 deletions(-)
diff --git a/fs/unionfs/dentry.c b/fs/unionfs/dentry.c
index c7bbeca..0be958f 100644
--- a/fs/unionfs/dentry.c
+++ b/fs/unionfs/dentry.c
@@ -450,9 +450,11 @@ static void unionfs_d_release(struct dentry *dentry)
bend = dbend(dentry);
for (bindex = bstart; bindex <= bend; bindex++) {
dput(unionfs_lower_dentry_idx(dentry, bindex));
- unionfs_mntput(dentry, bindex);
-
unionfs_set_lower_dentry_idx(dentry, bindex, NULL);
+ /* NULL lower mnt is ok if this is a negative dentry */
+ if (!dentry->d_inode && !unionfs_lower_mnt_idx(dentry,bindex))
+ continue;
+ unionfs_mntput(dentry, bindex);
unionfs_set_lower_mnt_idx(dentry, bindex, NULL);
}
/* free private data (unionfs_dentry_info) here */
diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c
index a219a40..d6a79d5 100644
--- a/fs/unionfs/inode.c
+++ b/fs/unionfs/inode.c
@@ -222,8 +222,11 @@ out:
dput(wh_dentry);
kfree(name);
+ if (!err)
+ unionfs_postcopyup_setmnt(dentry);
unionfs_unlock_dentry(dentry);
unionfs_read_unlock(dentry->d_sb);
+
return err;
}
@@ -563,8 +566,12 @@ out:
d_drop(dentry);
kfree(name);
+ if (!err)
+ unionfs_postcopyup_setmnt(dentry);
unionfs_unlock_dentry(dentry);
+
unionfs_read_unlock(dentry->d_sb);
+
return err;
}
@@ -835,8 +842,12 @@ out:
kfree(name);
+ if (!err)
+ unionfs_postcopyup_setmnt(dentry);
unionfs_unlock_dentry(dentry);
+
unionfs_read_unlock(dentry->d_sb);
+
return err;
}
diff --git a/fs/unionfs/lookup.c b/fs/unionfs/lookup.c
index 152d421..38ee21f 100644
--- a/fs/unionfs/lookup.c
+++ b/fs/unionfs/lookup.c
@@ -314,24 +314,25 @@ out_negative:
if (lookupmode == INTERPOSE_REVAL) {
if (dentry->d_inode)
UNIONFS_I(dentry->d_inode)->stale = 1;
-
goto out;
}
/* This should only happen if we found a whiteout. */
if (first_dentry_offset == -1) {
first_lower_dentry = lookup_one_len(name, lower_dir_dentry,
- namelen);
+ namelen);
first_dentry_offset = bindex;
if (IS_ERR(first_lower_dentry)) {
err = PTR_ERR(first_lower_dentry);
goto out;
}
-
- /* FIXME: the following line needs to be changed to allow
+
+ /*
+ * FIXME: the following line needs to be changed to allow
* mount-point crossing
*/
first_dentry = dentry;
- first_lower_mnt = unionfs_mntget(dentry, bindex);
+ first_lower_mnt = unionfs_mntget(dentry->d_sb->s_root,
+ bindex);
}
unionfs_set_lower_dentry_idx(dentry, first_dentry_offset,
first_lower_dentry);
diff --git a/fs/unionfs/union.h b/fs/unionfs/union.h
index 9f3e68a..33c2137 100644
--- a/fs/unionfs/union.h
+++ b/fs/unionfs/union.h
@@ -459,18 +459,49 @@ static inline void unlock_dir(struct dentry *dir)
static inline struct vfsmount *unionfs_mntget(struct dentry *dentry,
int bindex)
{
- BUG_ON(!dentry || bindex < 0);
-
- return mntget(unionfs_lower_mnt_idx(dentry, bindex));
+ struct vfsmount *mnt;
+
+ if (!dentry) {
+ if (bindex < 0)
+ return NULL;
+ if (!dentry && bindex >= 0) {
+ return NULL;
+ }
+ }
+ mnt = unionfs_lower_mnt_idx(dentry, bindex);
+ if (!mnt) {
+ if (bindex < 0)
+ return NULL;
+ if (!mnt && bindex >= 0) {
+ return NULL;
+ }
+ }
+ mnt = mntget(mnt);
+ return mnt;
}
static inline void unionfs_mntput(struct dentry *dentry, int bindex)
{
- if (!dentry)
- return;
+ struct vfsmount *mnt;
+
+ if (!dentry) {
+ if (bindex < 0)
+ return;
+ if (!dentry && bindex >= 0) {
+ return;
+ }
+ }
+ mnt = unionfs_lower_mnt_idx(dentry, bindex);
+ if (!mnt) {
+ if (bindex < 0)
+ return;
+ if (!mnt && bindex >= 0) {
+ return;
+ }
+ }
+ mntput(mnt);
+}
+
- BUG_ON(bindex < 0);
- mntput(unionfs_lower_mnt_idx(dentry, bindex));
-}
#endif /* not _UNION_H_ */
--
1.5.2.2.238.g7cbf2f2
-
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