From: Erez Zadok <ezk@xxxxxxxxxxxxx>
Be sure to properly revalidate all dentry chains passed to all inode and
super_block operations. Remove the older BUG_ON test is_valid_dentry().
This should help improve cache-coherency.
Signed-off-by: Erez Zadok <ezk@xxxxxxxxxxxxx>
Signed-off-by: Josef 'Jeff' Sipek <jsipek@xxxxxxxxxxxxx>
---
fs/unionfs/inode.c | 71 ++++++++++++++++++++++++++++++++++++++++-----------
fs/unionfs/rename.c | 13 +++++++--
fs/unionfs/super.c | 9 ++++++-
fs/unionfs/union.h | 13 ---------
fs/unionfs/unlink.c | 15 ++++++++---
fs/unionfs/xattr.c | 34 ++++++++++++++++++------
6 files changed, 111 insertions(+), 44 deletions(-)
diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c
index 9f1acc4..aaabfcf 100644
--- a/fs/unionfs/inode.c
+++ b/fs/unionfs/inode.c
@@ -47,7 +47,7 @@ static int unionfs_create(struct inode *parent, struct dentry *dentry,
valid = __unionfs_d_revalidate_chain(dentry->d_parent, nd);
unionfs_unlock_dentry(dentry->d_parent);
if (!valid) {
- err = -ENOENT; /* same as what real_lookup does */
+ err = -ESTALE; /* same as what real_lookup does */
goto out;
}
valid = __unionfs_d_revalidate_chain(dentry, nd);
@@ -234,6 +234,12 @@ static struct dentry *unionfs_lookup(struct inode *parent,
struct path path_save;
struct dentry *ret;
+ /*
+ * lookup is the only special function which takes a dentry, yet we
+ * do NOT want to call __unionfs_d_revalidate_chain because by
+ * definition, we don't have a valid dentry here yet.
+ */
+
/* save the dentry & vfsmnt from namei */
if (nd) {
path_save.dentry = nd->dentry;
@@ -262,11 +268,18 @@ static int unionfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *whiteout_dentry;
char *name = NULL;
- BUG_ON(!is_valid_dentry(new_dentry));
- BUG_ON(!is_valid_dentry(old_dentry));
-
unionfs_double_lock_dentry(new_dentry, old_dentry);
+ if (!__unionfs_d_revalidate_chain(old_dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+ if (new_dentry->d_inode &&
+ !__unionfs_d_revalidate_chain(new_dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
hidden_new_dentry = unionfs_lower_dentry(new_dentry);
/*
@@ -392,10 +405,14 @@ static int unionfs_symlink(struct inode *dir, struct dentry *dentry,
int bindex = 0, bstart;
char *name = NULL;
- BUG_ON(!is_valid_dentry(dentry));
-
unionfs_lock_dentry(dentry);
+ if (dentry->d_inode &&
+ !__unionfs_d_revalidate_chain(dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
/* We start out in the leftmost branch. */
bstart = dbstart(dentry);
@@ -534,9 +551,14 @@ static int unionfs_mkdir(struct inode *parent, struct dentry *dentry, int mode)
int whiteout_unlinked = 0;
struct sioq_args args;
- BUG_ON(!is_valid_dentry(dentry));
-
unionfs_lock_dentry(dentry);
+
+ if (dentry->d_inode &&
+ !__unionfs_d_revalidate_chain(dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
bstart = dbstart(dentry);
hidden_dentry = unionfs_lower_dentry(dentry);
@@ -667,9 +689,14 @@ static int unionfs_mknod(struct inode *dir, struct dentry *dentry, int mode,
char *name = NULL;
int whiteout_unlinked = 0;
- BUG_ON(!is_valid_dentry(dentry));
-
unionfs_lock_dentry(dentry);
+
+ if (dentry->d_inode &&
+ !__unionfs_d_revalidate_chain(dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
bstart = dbstart(dentry);
hidden_dentry = unionfs_lower_dentry(dentry);
@@ -774,9 +801,13 @@ static int unionfs_readlink(struct dentry *dentry, char __user *buf,
int err;
struct dentry *hidden_dentry;
- BUG_ON(!is_valid_dentry(dentry));
-
unionfs_lock_dentry(dentry);
+
+ if (!__unionfs_d_revalidate_chain(dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
hidden_dentry = unionfs_lower_dentry(dentry);
if (!hidden_dentry->d_inode->i_op ||
@@ -803,7 +834,13 @@ static void *unionfs_follow_link(struct dentry *dentry, struct nameidata *nd)
int len = PAGE_SIZE, err;
mm_segment_t old_fs;
- BUG_ON(!is_valid_dentry(dentry));
+ unionfs_lock_dentry(dentry);
+
+ if (dentry->d_inode &&
+ !__unionfs_d_revalidate_chain(dentry, nd)) {
+ err = -ESTALE;
+ goto out;
+ }
/* This is freed by the put_link method assuming a successful call. */
buf = kmalloc(len, GFP_KERNEL);
@@ -969,9 +1006,13 @@ static int unionfs_setattr(struct dentry *dentry, struct iattr *ia)
int i;
int copyup = 0;
- BUG_ON(!is_valid_dentry(dentry));
-
unionfs_lock_dentry(dentry);
+
+ if (!__unionfs_d_revalidate_chain(dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
bstart = dbstart(dentry);
bend = dbend(dentry);
inode = dentry->d_inode;
diff --git a/fs/unionfs/rename.c b/fs/unionfs/rename.c
index edc5a5c..4ceb815 100644
--- a/fs/unionfs/rename.c
+++ b/fs/unionfs/rename.c
@@ -398,11 +398,18 @@ int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,
int err = 0;
struct dentry *wh_dentry;
- BUG_ON(!is_valid_dentry(old_dentry));
- BUG_ON(!is_valid_dentry(new_dentry));
-
unionfs_double_lock_dentry(old_dentry, new_dentry);
+ if (!__unionfs_d_revalidate_chain(old_dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+ if (!d_deleted(new_dentry) && new_dentry->d_inode &&
+ !__unionfs_d_revalidate_chain(new_dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
if (!S_ISDIR(old_dentry->d_inode->i_mode))
err = unionfs_partial_lookup(old_dentry);
else
diff --git a/fs/unionfs/super.c b/fs/unionfs/super.c
index 196ff12..3f334f3 100644
--- a/fs/unionfs/super.c
+++ b/fs/unionfs/super.c
@@ -117,7 +117,12 @@ static int unionfs_statfs(struct dentry *dentry, struct kstatfs *buf)
struct super_block *sb;
struct dentry *lower_dentry;
- BUG_ON(!is_valid_dentry(dentry));
+ unionfs_lock_dentry(dentry);
+
+ if (!__unionfs_d_revalidate_chain(dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
sb = dentry->d_sb;
@@ -136,6 +141,8 @@ static int unionfs_statfs(struct dentry *dentry, struct kstatfs *buf)
memset(&buf->f_fsid, 0, sizeof(__kernel_fsid_t));
memset(&buf->f_spare, 0, sizeof(buf->f_spare));
+out:
+ unionfs_unlock_dentry(dentry);
return err;
}
diff --git a/fs/unionfs/union.h b/fs/unionfs/union.h
index 480b8ee..28eb622 100644
--- a/fs/unionfs/union.h
+++ b/fs/unionfs/union.h
@@ -401,19 +401,6 @@ static inline int is_robranch(const struct dentry *dentry)
return is_robranch_idx(dentry, index);
}
-/*
- * Check if dentry is valid or not, as per our generation numbers.
- * @dentry: dentry to check.
- * Returns 1 (valid) or 0 (invalid/stale).
- */
-static inline int is_valid_dentry(struct dentry *dentry)
-{
- BUG_ON(!UNIONFS_D(dentry));
- BUG_ON(!UNIONFS_SB(dentry->d_sb));
- return (atomic_read(&UNIONFS_D(dentry)->generation) ==
- atomic_read(&UNIONFS_SB(dentry->d_sb)->generation));
-}
-
/* What do we use for whiteouts. */
#define UNIONFS_WHPFX ".wh."
#define UNIONFS_WHLEN 4
diff --git a/fs/unionfs/unlink.c b/fs/unionfs/unlink.c
index 27b4542..c785ff0 100644
--- a/fs/unionfs/unlink.c
+++ b/fs/unionfs/unlink.c
@@ -74,15 +74,19 @@ int unionfs_unlink(struct inode *dir, struct dentry *dentry)
{
int err = 0;
- BUG_ON(!is_valid_dentry(dentry));
-
unionfs_lock_dentry(dentry);
+ if (!__unionfs_d_revalidate_chain(dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
err = unionfs_unlink_whiteout(dir, dentry);
/* call d_drop so the system "forgets" about us */
if (!err)
d_drop(dentry);
+out:
unionfs_unlock_dentry(dentry);
return err;
}
@@ -124,10 +128,13 @@ int unionfs_rmdir(struct inode *dir, struct dentry *dentry)
int err = 0;
struct unionfs_dir_state *namelist = NULL;
- BUG_ON(!is_valid_dentry(dentry));
-
unionfs_lock_dentry(dentry);
+ if (!__unionfs_d_revalidate_chain(dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
/* check if this unionfs directory is empty or not */
err = check_empty(dentry, &namelist);
if (err)
diff --git a/fs/unionfs/xattr.c b/fs/unionfs/xattr.c
index 12d618b..1beb373 100644
--- a/fs/unionfs/xattr.c
+++ b/fs/unionfs/xattr.c
@@ -57,14 +57,18 @@ ssize_t unionfs_getxattr(struct dentry *dentry, const char *name, void *value,
struct dentry *hidden_dentry = NULL;
int err = -EOPNOTSUPP;
- BUG_ON(!is_valid_dentry(dentry));
-
unionfs_lock_dentry(dentry);
+ if (!__unionfs_d_revalidate_chain(dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
hidden_dentry = unionfs_lower_dentry(dentry);
err = vfs_getxattr(hidden_dentry, (char*) name, value, size);
+out:
unionfs_unlock_dentry(dentry);
return err;
}
@@ -79,14 +83,19 @@ int unionfs_setxattr(struct dentry *dentry, const char *name,
struct dentry *hidden_dentry = NULL;
int err = -EOPNOTSUPP;
- BUG_ON(!is_valid_dentry(dentry));
-
unionfs_lock_dentry(dentry);
+
+ if (!__unionfs_d_revalidate_chain(dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
hidden_dentry = unionfs_lower_dentry(dentry);
err = vfs_setxattr(hidden_dentry, (char*) name, (void*) value,
size, flags);
+out:
unionfs_unlock_dentry(dentry);
return err;
}
@@ -100,13 +109,18 @@ int unionfs_removexattr(struct dentry *dentry, const char *name)
struct dentry *hidden_dentry = NULL;
int err = -EOPNOTSUPP;
- BUG_ON(!is_valid_dentry(dentry));
-
unionfs_lock_dentry(dentry);
+
+ if (!__unionfs_d_revalidate_chain(dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
hidden_dentry = unionfs_lower_dentry(dentry);
err = vfs_removexattr(hidden_dentry, (char*) name);
+out:
unionfs_unlock_dentry(dentry);
return err;
}
@@ -121,15 +135,19 @@ ssize_t unionfs_listxattr(struct dentry *dentry, char *list, size_t size)
int err = -EOPNOTSUPP;
char *encoded_list = NULL;
- BUG_ON(!is_valid_dentry(dentry));
-
unionfs_lock_dentry(dentry);
+ if (!__unionfs_d_revalidate_chain(dentry, NULL)) {
+ err = -ESTALE;
+ goto out;
+ }
+
hidden_dentry = unionfs_lower_dentry(dentry);
encoded_list = list;
err = vfs_listxattr(hidden_dentry, encoded_list, size);
+out:
unionfs_unlock_dentry(dentry);
return err;
}
--
1.5.2.rc1.165.gaf9b
-
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