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| author | Yunlei He <heyunlei@huawei.com> | 2017-09-07 10:40:54 +0800 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2017-09-07 20:57:20 -0700 |
| commit | 27161f13e3c3241944846ac24942a85cceda0a2c (patch) | |
| tree | bdd36b6171f9d48fd4a3c68c6f091697bb4cfaba /fs/f2fs/xattr.c | |
| parent | 13ba41e346170e594b7ce582561b3efa5b85f18f (diff) | |
| download | linux-27161f13e3c3241944846ac24942a85cceda0a2c.tar.bz2 | |
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 ef3a3721ea6b..7c65540148f8 100644 --- a/fs/f2fs/xattr.c +++ b/fs/f2fs/xattr.c @@ -473,8 +473,10 @@ 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; @@ -503,7 +505,9 @@ 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; @@ -686,7 +690,9 @@ 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); |