ext4: don't fail remount if journalling mode didn't change

PATCH Applied Lukas Czerner 2 participants 2 messages Dec 20, 2021 – Dec 23, 2021 ext4 file system

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Lukas Czerner

author

2021-12-20 15:27 UTC #0 lore raw

PATCH 1/1 ext4: don't fail remount if journalling mode didn't change

Switching to the new mount api introduced inconsistency in how the journalling mode mount option (data=) is handled during a remount.

Ext4 always prevented changing the journalling mode during the remount, however the new code always fails the remount when the journalling mode is specified, even if it remains unchanged. Fix it.

Signed-off-by Lukas Czerner <[email protected]>

Reported-by Heiner Kallweit <[email protected]>

Fixes cebe85d570cf ("ext4: switch to the new mount api")

---
 fs/ext4/super.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

fs/ext4/super.c +9 -5

index b72d989b77fb..dd9de4bf414d 100644
@@ -2148,19 +2148,22 @@ static int unnote_qf_name(struct fs_context *fc, int qtype)
 #endif
 
 #define EXT4_SET_CTX(name)						\
-static inline void ctx_set_##name(struct ext4_fs_context *ctx, int flag)\
+static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
+				  unsigned long flag)			\
 {									\
 	ctx->mask_s_##name |= flag;					\
 	ctx->vals_s_##name |= flag;					\
 }									\
-static inline void ctx_clear_##name(struct ext4_fs_context *ctx, int flag)\
+static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
+				    unsigned long flag)			\
 {									\
 	ctx->mask_s_##name |= flag;					\
 	ctx->vals_s_##name &= ~flag;					\
 }									\
-static inline bool ctx_test_##name(struct ext4_fs_context *ctx, int flag)\
+static inline unsigned long						\
+ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
 {									\
-	return ((ctx->vals_s_##name & flag) != 0);			\
+	return (ctx->vals_s_##name & flag);				\
 }									\
 
 EXT4_SET_CTX(flags);

@@ -2821,7 +2824,8 @@ static int ext4_check_opt_consistency(struct fs_context *fc,
 				 "Remounting file system with no journal "
 				 "so ignoring journalled data option");
 			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
-		} else if (ctx->mask_s_mount_opt & EXT4_MOUNT_DATA_FLAGS) {
+		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
+			   test_opt(sb, DATA_FLAGS)) {
 			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
 				 "on remount");
 			return -EINVAL;

Signature · 1 line

2.31.1

Theodore Ts'o

maintainer Applied

2021-12-23 15:36 UTC #1 lore raw

Quoted 8 lines · Lukas Czerner

Switching to the new mount api introduced inconsistency in how the journalling mode mount option (data=) is handled during a remount.
Ext4 always prevented changing the journalling mode during the remount, however the new code always fails the remount when the journalling mode is specified, even if it remains unchanged. Fix it.
[...]

Applied, thanks!

[1/1] ext4: don't fail remount if journalling mode didn't change

      commit: 4c2467287779f744cdd70c8ec70903034d6584f0

Best regards,

Signature · 1 line

Theodore Ts'o <[email protected]>