submit_bh: Drop unnecessary return value

PATCH Applied Ritesh Harjani (IBM) 3 participants 7 messages Aug 18, 2022 – Sep 29, 2022

Subsystems (3)

VFS Journalling layer for block devices (JBD2) NTFS filesystem

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Ritesh Harjani (IBM)

author

2022-08-18 05:05 UTC #0 lore raw

v3 cover submit_bh: Drop unnecessary return value

submit_bh/submit_bh_wbc are non-blocking functions which just submits the bio and returns. The caller of submit_bh/submit_bh_wbc needs to wait on buffer till I/O completion and then check buffer head's b_state field to know if there was any I/O error.

Hence there is no need for these functions to have any return type. Even now they always returns 0. Hence drop the return value and make their return type as void to avoid any confusion.

PATCHv2 -> PATCHv3
===================
1. Rebased on top of the latest 6.0-rc1 release.
Recently REQ_OP_** req operations and REQ_** flags were combined as one parameter (blk_opf_t type) to submit_bh() API.
2. Since the patch series remains trivial on rebase, I have retained the reviewed-by from Jan and Christoph.

RFC -> PATCHv2
===============
1. Added Patch-2 to fix ntfs_submit_bh_for_read() caller.
2. Added Reviewed-by from Christoph.

Ritesh Harjani (IBM) (4):
jbd2: Drop useless return value of submit_bh
fs/ntfs: Drop useless return value of submit_bh from ntfs_submit_bh_for_read fs/buffer: Drop useless return value of submit_bh
fs/buffer: Make submit_bh & submit_bh_wbc return type as void

 fs/buffer.c                 | 23 ++++++++++-------------
 fs/jbd2/commit.c            | 10 ++++------
 fs/jbd2/journal.c           |  9 ++++-----
 fs/ntfs/file.c              |  4 ++--
 include/linux/buffer_head.h |  2 +-
 5 files changed, 21 insertions(+), 27 deletions(-)

--
2.35.3

Ritesh Harjani (IBM)

author

2022-08-18 05:05 UTC #1 lore raw

PATCH v3 1/4 jbd2: Drop useless return value of submit_bh

submit_bh always returns 0. This patch cleans up 2 of it's caller in jbd2 to drop submit_bh's useless return value.
Once all submit_bh callers are cleaned up, we can make it's return type as void.

Reviewed-by Christoph Hellwig <[email protected]>

Reviewed-by Jan Kara <[email protected]>

Signed-off-by Ritesh Harjani (IBM) <[email protected]>

---
 fs/jbd2/commit.c  | 10 ++++------
 fs/jbd2/journal.c |  9 ++++-----
 2 files changed, 8 insertions(+), 11 deletions(-)

fs/jbd2/commit.c +4 -6

index b2b2bc9b88d9..6b51d2dc56e2 100644
@@ -122,8 +122,8 @@ static int journal_submit_commit_record(journal_t *journal,
 {
 	struct commit_header *tmp;
 	struct buffer_head *bh;
-	int ret;
 	struct timespec64 now;
+	blk_opf_t write_flags = REQ_OP_WRITE | REQ_SYNC;
 
 	*cbh = NULL;

@@ -155,13 +155,11 @@ static int journal_submit_commit_record(journal_t *journal,
 
 	if (journal->j_flags & JBD2_BARRIER &&
 	    !jbd2_has_feature_async_commit(journal))
-		ret = submit_bh(REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH |
-				REQ_FUA, bh);
-	else
-		ret = submit_bh(REQ_OP_WRITE | REQ_SYNC, bh);
+		write_flags |= REQ_PREFLUSH | REQ_FUA;
 
+	submit_bh(write_flags, bh);
 	*cbh = bh;
-	return ret;
+	return 0;
 }
 
 /*

fs/jbd2/journal.c +4 -5

index 6350d3857c89..f669ae1ff7a2 100644
@@ -1606,7 +1606,7 @@ static int jbd2_write_superblock(journal_t *journal, blk_opf_t write_flags)
 {
 	struct buffer_head *bh = journal->j_sb_buffer;
 	journal_superblock_t *sb = journal->j_superblock;
-	int ret;
+	int ret = 0;
 
 	/* Buffer got discarded which means block device got invalidated */
 	if (!buffer_mapped(bh)) {

@@ -1636,7 +1636,7 @@ static int jbd2_write_superblock(journal_t *journal, blk_opf_t write_flags)
 		sb->s_checksum = jbd2_superblock_csum(journal, sb);
 	get_bh(bh);
 	bh->b_end_io = end_buffer_write_sync;
-	ret = submit_bh(REQ_OP_WRITE | write_flags, bh);
+	submit_bh(REQ_OP_WRITE | write_flags, bh);
 	wait_on_buffer(bh);
 	if (buffer_write_io_error(bh)) {
 		clear_buffer_write_io_error(bh);

@@ -1644,9 +1644,8 @@ static int jbd2_write_superblock(journal_t *journal, blk_opf_t write_flags)
 		ret = -EIO;
 	}
 	if (ret) {
-		printk(KERN_ERR "JBD2: Error %d detected when updating "
-		       "journal superblock for %s.\n", ret,
-		       journal->j_devname);
+		printk(KERN_ERR "JBD2: I/O error when updating journal superblock for %s.\n",
+				journal->j_devname);
 		if (!is_journal_aborted(journal))
 			jbd2_journal_abort(journal, ret);
 	}

Signature · 1 line

2.35.3

Ritesh Harjani (IBM)

author

2022-08-18 05:05 UTC #2 lore raw

PATCH v3 2/4 fs/ntfs: Drop useless return value of submit_bh from ntfs_submit_bh_for_read

In reply to Ritesh Harjani (IBM)

submit_bh always returns 0. This patch drops the useless return value of submit_bh from ntfs_submit_bh_for_read(). Once all of submit_bh callers are cleaned up, we can make it's return type as void.

Reviewed-by Christoph Hellwig <[email protected]>

Reviewed-by Jan Kara <[email protected]>

Reported-by kernel test robot <[email protected]>

Signed-off-by Ritesh Harjani <[email protected]>

---
 fs/ntfs/file.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

fs/ntfs/file.c +2 -2

index 58b660dbbee9..c481b14e4fd9 100644
@@ -527,12 +527,12 @@ static inline int __ntfs_grab_cache_pages(struct address_space *mapping,
 	goto out;
 }
 
-static inline int ntfs_submit_bh_for_read(struct buffer_head *bh)
+static inline void ntfs_submit_bh_for_read(struct buffer_head *bh)
 {
 	lock_buffer(bh);
 	get_bh(bh);
 	bh->b_end_io = end_buffer_read_sync;
-	return submit_bh(REQ_OP_READ, bh);
+	submit_bh(REQ_OP_READ, bh);
 }
 
 /**

Signature · 1 line

2.35.3

Ritesh Harjani (IBM)

author

2022-08-18 05:05 UTC #3 lore raw

PATCH v3 3/4 fs/buffer: Drop useless return value of submit_bh

In reply to Ritesh Harjani (IBM)

submit_bh always returns 0. This patch drops the useless return value of submit_bh from __sync_dirty_buffer(). Once all of submit_bh callers are cleaned up, we can make it's return type as void.

Signed-off-by Ritesh Harjani (IBM) <[email protected]>

---
 fs/buffer.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

fs/buffer.c +4 -6

index 55e762a58eb6..c21b72c06eb0 100644
@@ -2801,8 +2801,6 @@ EXPORT_SYMBOL(write_dirty_buffer);
  */
 int __sync_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags)
 {
-	int ret = 0;
-
 	WARN_ON(atomic_read(&bh->b_count) < 1);
 	lock_buffer(bh);
 	if (test_clear_buffer_dirty(bh)) {

@@ -2817,14 +2815,14 @@ int __sync_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags)
 
 		get_bh(bh);
 		bh->b_end_io = end_buffer_write_sync;
-		ret = submit_bh(REQ_OP_WRITE | op_flags, bh);
+		submit_bh(REQ_OP_WRITE | op_flags, bh);
 		wait_on_buffer(bh);
-		if (!ret && !buffer_uptodate(bh))
-			ret = -EIO;
+		if (!buffer_uptodate(bh))
+			return -EIO;
 	} else {
 		unlock_buffer(bh);
 	}
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(__sync_dirty_buffer);

Signature · 1 line

2.35.3

Jan Kara

reviewer Reviewed-by on v3 3/4

2022-08-18 14:16 UTC #4 lore raw

Re: [PATCHv3 3/4] fs/buffer: Drop useless return value of submit_bh

Quoted 5 lines · Ritesh Harjani (IBM)

submit_bh always returns 0. This patch drops the useless return value of submit_bh from __sync_dirty_buffer(). Once all of submit_bh callers are cleaned up, we can make it's return type as void.
Signed-off-by Ritesh Harjani (IBM) <[email protected]>

Looks good. Feel free to add:

Reviewed-by Jan Kara <[email protected]>

Honza

Quoted 39 lines

---
 fs/buffer.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

fs/buffer.c +4 -6

index 55e762a58eb6..c21b72c06eb0 100644
@@ -2801,8 +2801,6 @@ EXPORT_SYMBOL(write_dirty_buffer);
  */
 int __sync_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags)
 {
-	int ret = 0;
-
 	WARN_ON(atomic_read(&bh->b_count) < 1);
 	lock_buffer(bh);
 	if (test_clear_buffer_dirty(bh)) {

@@ -2817,14 +2815,14 @@ int __sync_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags)
 
 		get_bh(bh);
 		bh->b_end_io = end_buffer_write_sync;
-		ret = submit_bh(REQ_OP_WRITE | op_flags, bh);
+		submit_bh(REQ_OP_WRITE | op_flags, bh);
 		wait_on_buffer(bh);
-		if (!ret && !buffer_uptodate(bh))
-			ret = -EIO;
+		if (!buffer_uptodate(bh))
+			return -EIO;
 	} else {
 		unlock_buffer(bh);
 	}
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(__sync_dirty_buffer);

Signature · 1 line

2.35.3

Signature · 2 lines

Jan Kara <[email protected]>
SUSE Labs, CR

Ritesh Harjani (IBM)

author

2022-08-18 05:05 UTC #5 lore raw

PATCH v3 4/4 fs/buffer: Make submit_bh & submit_bh_wbc return type as void

In reply to Ritesh Harjani (IBM)

submit_bh/submit_bh_wbc are non-blocking functions which just submit the bio and return. The caller of submit_bh/submit_bh_wbc needs to wait on buffer till I/O completion and then check buffer head's b_state field to know if there was any I/O error.

Hence there is no need for these functions to have any return type. Even now they always returns 0. Hence drop the return value and make their return type as void to avoid any confusion.

Reviewed-by Christoph Hellwig <[email protected]>

Reviewed-by Jan Kara <[email protected]>

Signed-off-by Ritesh Harjani (IBM) <[email protected]>

---
 fs/buffer.c                 | 13 ++++++-------
 include/linux/buffer_head.h |  2 +-
 2 files changed, 7 insertions(+), 8 deletions(-)

fs/buffer.c +6 -7

index c21b72c06eb0..0a7ba84c1905 100644
@@ -52,8 +52,8 @@
 #include "internal.h"
 
 static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
-static int submit_bh_wbc(blk_opf_t opf, struct buffer_head *bh,
-			 struct writeback_control *wbc);
+static void submit_bh_wbc(blk_opf_t opf, struct buffer_head *bh,
+			  struct writeback_control *wbc);
 
 #define BH_ENTRY(list) list_entry((list), struct buffer_head, b_assoc_buffers)

@@ -2673,8 +2673,8 @@ static void end_bio_bh_io_sync(struct bio *bio)
 	bio_put(bio);
 }
 
-static int submit_bh_wbc(blk_opf_t opf, struct buffer_head *bh,
-			 struct writeback_control *wbc)
+static void submit_bh_wbc(blk_opf_t opf, struct buffer_head *bh,
+			  struct writeback_control *wbc)
 {
 	const enum req_op op = opf & REQ_OP_MASK;
 	struct bio *bio;

@@ -2717,12 +2717,11 @@ static int submit_bh_wbc(blk_opf_t opf, struct buffer_head *bh,
 	}
 
 	submit_bio(bio);
-	return 0;
 }
 
-int submit_bh(blk_opf_t opf, struct buffer_head *bh)
+void submit_bh(blk_opf_t opf, struct buffer_head *bh)
 {
-	return submit_bh_wbc(opf, bh, NULL);
+	submit_bh_wbc(opf, bh, NULL);
 }
 EXPORT_SYMBOL(submit_bh);

include/linux/buffer_head.h +1 -1

index def8b8d30ccc..b1373844c43d 100644
@@ -229,7 +229,7 @@ void ll_rw_block(blk_opf_t, int, struct buffer_head * bh[]);
 int sync_dirty_buffer(struct buffer_head *bh);
 int __sync_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags);
 void write_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags);
-int submit_bh(blk_opf_t, struct buffer_head *);
+void submit_bh(blk_opf_t, struct buffer_head *);
 void write_boundary_block(struct block_device *bdev,
 			sector_t bblock, unsigned blocksize);
 int bh_uptodate_or_lock(struct buffer_head *bh);

Signature · 1 line

2.35.3

Theodore Ts'o

maintainer Applied

2022-09-29 14:59 UTC #6 lore raw

In reply to Ritesh Harjani (IBM)

Quoted 10 lines · Ritesh Harjani (IBM)

submit_bh/submit_bh_wbc are non-blocking functions which just submits the bio and returns. The caller of submit_bh/submit_bh_wbc needs to wait on buffer till I/O completion and then check buffer head's b_state field to know if there was any I/O error.
Hence there is no need for these functions to have any return type. Even now they always returns 0. Hence drop the return value and make their return type as void to avoid any confusion.
[...]

Applied, thanks!

[1/4] jbd2: Drop useless return value of submit_bh

      commit: c2939da1fe8b25c82c1991eb983638463ed84a0c
[2/4] fs/ntfs: Drop useless return value of submit_bh from ntfs_submit_bh_for_read
      commit: f102f1ab784c91c559a3505d024008ff2decc77f
[3/4] fs/buffer: Drop useless return value of submit_bh
      commit: 7cb83d3c0c485b3b035cdcac4c6ef4937f920c59
[4/4] fs/buffer: Make submit_bh & submit_bh_wbc return type as void
      commit: 54a55bcabb92f7522e006ca38575159c41914c56

Best regards,

Signature · 1 line

Theodore Ts'o <[email protected]>