From: Russ Knize <russ.kn...@motorola.com>
f2fs_initxattrs() is called internally from within F2FS and should
not call functions that are used by VFS handlers. This avoids
certain deadlocks:
- vfs_create()
- f2fs_create() <-- takes an fs_lock
- f2fs_add_link()
- __f2fs_add_link()
- init_inode_metadata()
- f2fs_init_security()
- security_inode_init_security()
- f2fs_initxattrs()
- f2fs_setxattr() <-- also takes an fs_lock
If the caller happens to grab the same fs_lock from the pool in both
places, they will deadlock. There are also deadlocks involving
multiple threads and mutexes:
- f2fs_write_begin()
- f2fs_balance_fs() <-- takes gc_mutex
- f2fs_gc()
- write_checkpoint()
- block_operations()
- mutex_lock_all() <-- blocks trying to grab all fs_locks
- f2fs_mkdir() <-- takes an fs_lock
- __f2fs_add_link()
- f2fs_init_security()
- security_inode_init_security()
- f2fs_initxattrs()
- f2fs_setxattr()
- f2fs_balance_fs() <-- blocks trying to take gc_mutex
Signed-off-by: Russ Knize <russ.kn...@motorola.com>
---
fs/f2fs/xattr.c | 35 +++++++++++++++++++++++++----------
1 file changed, 25 insertions(+), 10 deletions(-)
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 1ac8a5f..3d900ea 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -154,6 +154,9 @@ static int f2fs_xattr_advise_set(struct dentry *dentry,
const char *name,
}
#ifdef CONFIG_F2FS_FS_SECURITY
+static int __f2fs_setxattr(struct inode *inode, int name_index,
+ const char *name, const void *value, size_t value_len,
+ struct page *ipage);
static int f2fs_initxattrs(struct inode *inode, const struct xattr
*xattr_array,
void *page)
{
@@ -161,7 +164,7 @@ static int f2fs_initxattrs(struct inode *inode, const
struct xattr *xattr_array,
int err = 0;
for (xattr = xattr_array; xattr->name != NULL; xattr++) {
- err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
+ err = __f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
xattr->name, xattr->value,
xattr->value_len, (struct page *)page);
if (err < 0)
@@ -469,16 +472,15 @@ cleanup:
return error;
}
-int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
- const void *value, size_t value_len, struct page *ipage)
+static int __f2fs_setxattr(struct inode *inode, int name_index,
+ const char *name, const void *value, size_t value_len,
+ struct page *ipage)
{
- struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct f2fs_inode_info *fi = F2FS_I(inode);
struct f2fs_xattr_entry *here, *last;
void *base_addr;
int found, newsize;
size_t name_len;
- int ilock;
__u32 new_hsize;
int error = -ENOMEM;
@@ -493,10 +495,6 @@ int f2fs_setxattr(struct inode *inode, int name_index,
const char *name,
if (name_len > F2FS_NAME_LEN || value_len > MAX_VALUE_LEN(inode))
return -ERANGE;
- f2fs_balance_fs(sbi);
-
- ilock = mutex_lock_op(sbi);
-
base_addr = read_all_xattrs(inode, ipage);
if (!base_addr)
goto exit;
@@ -578,7 +576,24 @@ int f2fs_setxattr(struct inode *inode, int name_index,
const char *name,
else
update_inode_page(inode);
exit:
- mutex_unlock_op(sbi, ilock);
kzfree(base_addr);
return error;
}
+
+int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
+ const void *value, size_t value_len, struct page *ipage)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ int ilock;
+ int err;
+
+ f2fs_balance_fs(sbi);
+
+ ilock = mutex_lock_op(sbi);
+
+ err = __f2fs_setxattr(inode, name_index, name, value, value_len, ipage);
+
+ mutex_unlock_op(sbi, ilock);
+
+ return err;
+}
--
1.7.10.4
------------------------------------------------------------------------------
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