diff options
| author | Yunlei He <heyunlei@huawei.com> | 2017-09-07 10:40:54 +0800 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-10-04 15:35:28 +0200 |
| commit | 0ff9056dd63fbbe7da6801c9c7ccc19b6e772411 (patch) | |
| tree | 067bdc7b8c98afe15b535ce031cc47aed37c30a8 /fs/f2fs/xattr.c | |
| parent | 3aafd042cab3558fb7bb65f5138ec5f23fba33e5 (diff) | |
f2fs: avoid race in between read xattr & write xattr
Thread A: Thread B:
-f2fs_getxattr
-lookup_all_xattrs
-xnid = F2FS_I(inode)->i_xattr_nid;
-f2fs_setxattr
-__f2fs_setxattr
-write_all_xattrs
-truncate_xattr_node
... ...
-write_checkpoint
... ...
-alloc_nid <- nid reuse
-get_node_page
-f2fs_bug_on <- nid != node_footer->nid
It's need a rw_sem to avoid the race
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs/xattr.c')
| -rw-r--r-- | fs/f2fs/xattr.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c index 644ce6994..c6e9f211b 100644 --- a/fs/f2fs/xattr.c +++ b/fs/f2fs/xattr.c @@ -521,8 +521,10 @@ int f2fs_getxattr(struct inode *inode, int index, const char *name, if (len > F2FS_NAME_LEN) return -ERANGE; + down_read(&F2FS_I(inode)->i_xattr_sem); error = lookup_all_xattrs(inode, ipage, index, len, name, &entry, &base_addr); + up_read(&F2FS_I(inode)->i_xattr_sem); if (error) return error; @@ -551,7 +553,9 @@ ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) int error = 0; size_t rest = buffer_size; + down_read(&F2FS_I(inode)->i_xattr_sem); error = read_all_xattrs(inode, NULL, &base_addr); + up_read(&F2FS_I(inode)->i_xattr_sem); if (error) return error; @@ -727,7 +731,9 @@ int f2fs_setxattr(struct inode *inode, int index, const char *name, f2fs_lock_op(sbi); /* protect xattr_ver */ down_write(&F2FS_I(inode)->i_sem); + down_write(&F2FS_I(inode)->i_xattr_sem); err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags); + up_write(&F2FS_I(inode)->i_xattr_sem); up_write(&F2FS_I(inode)->i_sem); f2fs_unlock_op(sbi); |