ext4: add mask of ext4 flags to swap

The reason is that while swapping two inode, we swap the flags too. Some flags such as EXT4_JOURNAL_DATA_FL can really confuse the things since we're not resetting the address operations structure. The simplest way to keep things sane is to restrict the flags that can be swapped. Signed-off-by: yangerkun <[email protected]> Signed-off-by: Theodore Ts'o <[email protected]> Cc: [email protected]
chewitt · Feb 11, 2019 · abdc644 · abdc644
1 parent aa507b5
commit abdc644
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Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
@@ -426,6 +426,9 @@ struct flex_groups {
 /* Flags that are appropriate for non-directories/regular files. */
 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
 
+/* The only flags that should be swapped */
+#define EXT4_FL_SHOULD_SWAP (EXT4_HUGE_FILE_FL | EXT4_EXTENTS_FL)
+
 /* Mask out flags that are inappropriate for the given type of inode. */
 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
 {

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
@@ -63,6 +63,7 @@ static void swap_inode_data(struct inode *inode1, struct inode *inode2)
 	loff_t isize;
 	struct ext4_inode_info *ei1;
 	struct ext4_inode_info *ei2;
+	unsigned long tmp;
 
 	ei1 = EXT4_I(inode1);
 	ei2 = EXT4_I(inode2);
@@ -72,7 +73,10 @@ static void swap_inode_data(struct inode *inode1, struct inode *inode2)
 	swap(inode1->i_mtime, inode2->i_mtime);
 
 	memswap(ei1->i_data, ei2->i_data, sizeof(ei1->i_data));
-	swap(ei1->i_flags, ei2->i_flags);
+	tmp = ei1->i_flags & EXT4_FL_SHOULD_SWAP;
+	ei1->i_flags = (ei2->i_flags & EXT4_FL_SHOULD_SWAP) |
+		(ei1->i_flags & ~EXT4_FL_SHOULD_SWAP);
+	ei2->i_flags = tmp | (ei2->i_flags & ~EXT4_FL_SHOULD_SWAP);
 	swap(ei1->i_disksize, ei2->i_disksize);
 	ext4_es_remove_extent(inode1, 0, EXT_MAX_BLOCKS);
 	ext4_es_remove_extent(inode2, 0, EXT_MAX_BLOCKS);