ext4: fix xattr deadlock
ext4_xattr_set_handle() eventually ends up calling
ext4_mark_inode_dirty() which tries to expand the inode by shifting
the EAs. This leads to the xattr_sem being downed again and leading
to a deadlock.
This patch makes sure that if ext4_xattr_set_handle() is in the
call-chain, ext4_mark_inode_dirty() will not expand the inode.
Signed-off-by: Kalpak Shah <kalpak.shah@sun.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 8954208..362b0ed 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -959,6 +959,7 @@
struct ext4_xattr_block_find bs = {
.s = { .not_found = -ENODATA, },
};
+ unsigned long no_expand;
int error;
if (!name)
@@ -966,6 +967,9 @@
if (strlen(name) > 255)
return -ERANGE;
down_write(&EXT4_I(inode)->xattr_sem);
+ no_expand = EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND;
+ EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND;
+
error = ext4_get_inode_loc(inode, &is.iloc);
if (error)
goto cleanup;
@@ -1042,6 +1046,8 @@
cleanup:
brelse(is.iloc.bh);
brelse(bs.bh);
+ if (no_expand == 0)
+ EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND;
up_write(&EXT4_I(inode)->xattr_sem);
return error;
}
