| From | Kamal Mostafa <> | Subject | [PATCH 3.13 147/163] shmem: fix nlink for rename overwrite directory | Date | Thu, 9 Oct 2014 14:02:52 -0700 |
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3.13.11.9 -stable review patch. If anyone has any objections, please let me know.
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From: Miklos Szeredi <mszeredi@suse.cz>
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@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- mm/shmem.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/shmem.c b/mm/shmem.c index de64924..bed15b5 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2157,8 +2157,10 @@ 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); -- 1.9.1
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