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ext4: journal_path mount options should follow links

PATCH Applied Lukas Czerner 3 participants 3 messages Oct 4, 2022 – Nov 29, 2022

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Lukas Czerner

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#0 lore raw

PATCH 1/1 ext4: journal_path mount options should follow links

Before the commit 461c3af045d3 ("ext4: Change handle_mount_opt() to use fs_parameter") ext4 mount option journal_path did follow links in the provided path.

Bring this behavior back by allowing to pass pathwalk flags to fs_lookup_param().

Fixes 461c3af045d3 ("ext4: Change handle_mount_opt() to use fs_parameter")
Signed-off-by Lukas Czerner <[email protected]>
---
 Documentation/filesystems/mount_api.rst | 1 +
 fs/ext4/super.c                         | 2 +-
 fs/fs_parser.c                          | 3 ++-
 include/linux/fs_parser.h               | 1 +
 4 files changed, 5 insertions(+), 2 deletions(-)
Documentation/filesystems/mount_api.rst +1 -0
index eb358a00be27..1d16787a00e9 100644
@@ -814,6 +814,7 @@ process the parameters it is given.
        int fs_lookup_param(struct fs_context *fc,
 			   struct fs_parameter *value,
 			   bool want_bdev,
+			   unsigned int flags,
 			   struct path *_path);
 
      This takes a parameter that carries a string or filename type and attempts
fs/ext4/super.c +1 -1
index 9a66abcca1a8..4c1b3972d53f 100644
@@ -2271,7 +2271,7 @@ static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
 			return -EINVAL;
 		}
 
-		error = fs_lookup_param(fc, param, 1, &path);
+		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
 		if (error) {
 			ext4_msg(NULL, KERN_ERR, "error: could not find "
 				 "journal device path");
fs/fs_parser.c +2 -1
index ed40ce5742fd..edb3712dcfa5 100644
@@ -138,15 +138,16 @@ EXPORT_SYMBOL(__fs_parse);
  * @fc: The filesystem context to log errors through.
  * @param: The parameter.
  * @want_bdev: T if want a blockdev
+ * @flags: Pathwalk flags passed to filename_lookup()
  * @_path: The result of the lookup
  */
 int fs_lookup_param(struct fs_context *fc,
 		    struct fs_parameter *param,
 		    bool want_bdev,
+		    unsigned int flags,
 		    struct path *_path)
 {
 	struct filename *f;
-	unsigned int flags = 0;
 	bool put_f;
 	int ret;
include/linux/fs_parser.h +1 -0
index f103c91139d4..01542c4b87a2 100644
@@ -76,6 +76,7 @@ static inline int fs_parse(struct fs_context *fc,
 extern int fs_lookup_param(struct fs_context *fc,
 			   struct fs_parameter *param,
 			   bool want_bdev,
+			   unsigned int flags,
 			   struct path *_path);
 
 extern int lookup_constant(const struct constant_table tbl[], const char *name, int not_found);
Signature · 1 line
2.37.3
Reviewed-by on v1 1/1
#1 lore raw
Quoted 9 lines · Lukas Czerner

Before the commit 461c3af045d3 ("ext4: Change handle_mount_opt() to use fs_parameter") ext4 mount option journal_path did follow links in the provided path.

Bring this behavior back by allowing to pass pathwalk flags to fs_lookup_param().

Fixes 461c3af045d3 ("ext4: Change handle_mount_opt() to use fs_parameter")
Signed-off-by Lukas Czerner <[email protected]>

This bit me recently when I was debugging an old system that used an external journal on an LVM LV and I wanted to know if the bug I was chasing also reproduced on upstream. Thanks for fixing this before I got around to making a patch:

Reviewed-by Darrick J. Wong <[email protected]>

--D

Quoted 69 lines
---
 Documentation/filesystems/mount_api.rst | 1 +
 fs/ext4/super.c                         | 2 +-
 fs/fs_parser.c                          | 3 ++-
 include/linux/fs_parser.h               | 1 +
 4 files changed, 5 insertions(+), 2 deletions(-)
Documentation/filesystems/mount_api.rst +1 -0
index eb358a00be27..1d16787a00e9 100644
@@ -814,6 +814,7 @@ process the parameters it is given.
        int fs_lookup_param(struct fs_context *fc,
 			   struct fs_parameter *value,
 			   bool want_bdev,
+			   unsigned int flags,
 			   struct path *_path);
 
      This takes a parameter that carries a string or filename type and attempts
fs/ext4/super.c +1 -1
index 9a66abcca1a8..4c1b3972d53f 100644
@@ -2271,7 +2271,7 @@ static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
 			return -EINVAL;
 		}
 
-		error = fs_lookup_param(fc, param, 1, &path);
+		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
 		if (error) {
 			ext4_msg(NULL, KERN_ERR, "error: could not find "
 				 "journal device path");
fs/fs_parser.c +2 -1
index ed40ce5742fd..edb3712dcfa5 100644
@@ -138,15 +138,16 @@ EXPORT_SYMBOL(__fs_parse);
  * @fc: The filesystem context to log errors through.
  * @param: The parameter.
  * @want_bdev: T if want a blockdev
+ * @flags: Pathwalk flags passed to filename_lookup()
  * @_path: The result of the lookup
  */
 int fs_lookup_param(struct fs_context *fc,
 		    struct fs_parameter *param,
 		    bool want_bdev,
+		    unsigned int flags,
 		    struct path *_path)
 {
 	struct filename *f;
-	unsigned int flags = 0;
 	bool put_f;
 	int ret;
include/linux/fs_parser.h +1 -0
index f103c91139d4..01542c4b87a2 100644
@@ -76,6 +76,7 @@ static inline int fs_parse(struct fs_context *fc,
 extern int fs_lookup_param(struct fs_context *fc,
 			   struct fs_parameter *param,
 			   bool want_bdev,
+			   unsigned int flags,
 			   struct path *_path);
 
 extern int lookup_constant(const struct constant_table tbl[], const char *name, int not_found);
Signature · 1 line
2.37.3
maintainer Applied
#2 lore raw
In reply to Lukas Czerner
Quoted 8 lines · Lukas Czerner

Before the commit 461c3af045d3 ("ext4: Change handle_mount_opt() to use fs_parameter") ext4 mount option journal_path did follow links in the provided path.

Bring this behavior back by allowing to pass pathwalk flags to fs_lookup_param().

[...]

Applied, thanks!

[1/1] ext4: journal_path mount options should follow links

      commit: c5d6c14eac604c4ef551e2751726f665b3f09e32

Best regards,

Signature · 1 line
Theodore Ts'o <[email protected]>