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authorYunlei He <heyunlei@huawei.com>2017-09-07 10:40:54 +0800
committerJaegeuk Kim <jaegeuk@kernel.org>2017-09-07 20:57:20 -0700
commit27161f13e3c3241944846ac24942a85cceda0a2c (patch)
treebdd36b6171f9d48fd4a3c68c6f091697bb4cfaba /fs
parent13ba41e346170e594b7ce582561b3efa5b85f18f (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')
-rw-r--r--fs/f2fs/f2fs.h1
-rw-r--r--fs/f2fs/super.c1
-rw-r--r--fs/f2fs/xattr.c6
3 files changed, 8 insertions, 0 deletions
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 91fb749686f2..c0803b1873b3 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -589,6 +589,7 @@ struct f2fs_inode_info {
struct extent_tree *extent_tree; /* cached extent_tree entry */
struct rw_semaphore dio_rwsem[2];/* avoid racing between dio and gc */
struct rw_semaphore i_mmap_sem;
+ struct rw_semaphore i_xattr_sem; /* avoid racing between reading and changing EAs */
int i_extra_isize; /* size of extra space located in i_addr */
kprojid_t i_projid; /* id for project quota */
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 7730316c19c6..89f61eb3d167 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -630,6 +630,7 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb)
init_rwsem(&fi->dio_rwsem[READ]);
init_rwsem(&fi->dio_rwsem[WRITE]);
init_rwsem(&fi->i_mmap_sem);
+ init_rwsem(&fi->i_xattr_sem);
#ifdef CONFIG_QUOTA
memset(&fi->i_dquot, 0, sizeof(fi->i_dquot));
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);