If we cache a dirent for file "foo", and then it gets deleted, then we look
for a ".wh.foo" whiteout entry in the same dirent cache. But our dirent
cache strips the ".wh." prefix, thus looking for an entry named "foo" whose
filldir_node->whiteout should be 1 instead of 0. In that case, don't
display an incorrect printk message that the file system may be corrupt,
but set that filldir_node->whiteout to 1.
CC: Hugh Dickins <hugh@xxxxxxxxxxx>
Signed-off-by: Erez Zadok <ezk@xxxxxxxxxxxxx>
---
fs/unionfs/dirfops.c | 13 ++++++++++---
fs/unionfs/dirhelper.c | 2 +-
fs/unionfs/rdstate.c | 11 +++++++----
fs/unionfs/union.h | 3 ++-
4 files changed, 20 insertions(+), 9 deletions(-)
diff --git a/fs/unionfs/dirfops.c b/fs/unionfs/dirfops.c
index 5276cb3..88df635 100644
--- a/fs/unionfs/dirfops.c
+++ b/fs/unionfs/dirfops.c
@@ -53,10 +53,17 @@ static int unionfs_filldir(void *dirent, const char *name, int namelen,
is_wh_entry = 1;
}
- found = find_filldir_node(buf->rdstate, name, namelen);
-
- if (found)
+ found = find_filldir_node(buf->rdstate, name, namelen, is_wh_entry);
+
+ if (found) {
+ /*
+ * If we had non-whiteout entry in dir cache, then mark it
+ * as a whiteout and but leave it in the dir cache.
+ */
+ if (is_wh_entry && !found->whiteout)
+ found->whiteout = is_wh_entry;
goto out;
+ }
/* if 'name' isn't a whiteout, filldir it. */
if (!is_wh_entry) {
diff --git a/fs/unionfs/dirhelper.c b/fs/unionfs/dirhelper.c
index 7a28444..2e52fc3 100644
--- a/fs/unionfs/dirhelper.c
+++ b/fs/unionfs/dirhelper.c
@@ -158,7 +158,7 @@ static int readdir_util_callback(void *dirent, const char *name, int namelen,
whiteout = 1;
}
- found = find_filldir_node(buf->rdstate, name, namelen);
+ found = find_filldir_node(buf->rdstate, name, namelen, whiteout);
/* If it was found in the table there was a previous whiteout. */
if (found)
goto out;
diff --git a/fs/unionfs/rdstate.c b/fs/unionfs/rdstate.c
index bdf335d..7ba1e1a 100644
--- a/fs/unionfs/rdstate.c
+++ b/fs/unionfs/rdstate.c
@@ -188,7 +188,8 @@ void free_rdstate(struct unionfs_dir_state *state)
}
struct filldir_node *find_filldir_node(struct unionfs_dir_state *rdstate,
- const char *name, int namelen)
+ const char *name, int namelen,
+ int is_whiteout)
{
int index;
unsigned int hash;
@@ -215,10 +216,12 @@ struct filldir_node *find_filldir_node(struct unionfs_dir_state *rdstate,
found = 1;
/*
- * if the duplicate is in this branch, then the file
- * system is corrupted.
+ * if a duplicate is found in this branch, and is
+ * not due to the caller looking for an entry to
+ * whiteout, then the file system may be corrupted.
*/
- if (unlikely(cursor->bindex == rdstate->bindex))
+ if (unlikely(!is_whiteout &&
+ cursor->bindex == rdstate->bindex))
printk(KERN_ERR "unionfs: filldir: possible "
"I/O error: a file is duplicated "
"in the same branch %d: %s\n",
diff --git a/fs/unionfs/union.h b/fs/unionfs/union.h
index f61e32d..283b085 100644
--- a/fs/unionfs/union.h
+++ b/fs/unionfs/union.h
@@ -223,7 +223,8 @@ extern int add_filldir_node(struct unionfs_dir_state *rdstate,
const char *name, int namelen, int bindex,
int whiteout);
extern struct filldir_node *find_filldir_node(struct unionfs_dir_state *rdstate,
- const char *name, int namelen);
+ const char *name, int namelen,
+ int is_whiteout);
extern struct dentry **alloc_new_dentries(int objs);
extern struct unionfs_data *alloc_new_data(int objs);
--
1.5.2.2
-
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