From: Miklos Szeredi <mszeredi@xxxxxxx>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit b928095b0a7cff7fb9fcf4c706348ceb8ab2c295 upstream.
If overwriting an empty directory with rename, then need to drop the extra
nlink.
Test prog:
#include <stdio.h>
#include <fcntl.h>
#include <err.h>
#include <sys/stat.h>
int main(void)
{
const char *test_dir1 = "test-dir1";
const char *test_dir2 = "test-dir2";
int res;
int fd;
struct stat statbuf;
res = mkdir(test_dir1, 0777);
if (res == -1)
err(1, "mkdir(\"%s\")", test_dir1);
res = mkdir(test_dir2, 0777);
if (res == -1)
err(1, "mkdir(\"%s\")", test_dir2);
fd = open(test_dir2, O_RDONLY);
if (fd == -1)
err(1, "open(\"%s\")", test_dir2);
res = rename(test_dir1, test_dir2);
if (res == -1)
err(1, "rename(\"%s\", \"%s\")", test_dir1, test_dir2);
res = fstat(fd, &statbuf);
if (res == -1)
err(1, "fstat(%i)", fd);
if (statbuf.st_nlink != 0) {
fprintf(stderr, "nlink is %lu, should be 0\n", statbuf.st_nlink);
return 1;
}
return 0;
}
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
mm/shmem.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index ab05681f41cd..e9502a67e300 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2106,8 +2106,10 @@ static int shmem_rename(struct inode *old_dir, struct dentry *old_dentry, struct
if (new_dentry->d_inode) {
(void) shmem_unlink(new_dir, new_dentry);
- if (they_are_dirs)
+ if (they_are_dirs) {
+ drop_nlink(new_dentry->d_inode);
drop_nlink(old_dir);
+ }
} else if (they_are_dirs) {
drop_nlink(old_dir);
inc_nlink(new_dir);
--
2.1.1
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