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* [PATCH 1/2] Use 'inode' variable that is already dereferenced
@ 2012-10-15 19:06 Anatol Pomozov
  2012-10-15 19:06 ` [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock() Anatol Pomozov
  2012-10-16  2:28 ` [PATCH 1/2] Use 'inode' variable that is already dereferenced Zheng Liu
  0 siblings, 2 replies; 9+ messages in thread
From: Anatol Pomozov @ 2012-10-15 19:06 UTC (permalink / raw)
  To: tytso, wenqing.lz, linux-ext4; +Cc: Anatol Pomozov

Tested: xfs tests

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
---
 fs/ext4/page-io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 68e896e..0fd16e6 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -111,7 +111,7 @@ static int ext4_end_io(ext4_io_end_t *io)
 		inode_dio_done(inode);
 	/* Wake up anyone waiting on unwritten extent conversion */
 	if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten))
-		wake_up_all(ext4_ioend_wq(io->inode));
+		wake_up_all(ext4_ioend_wq(inode));
 	return ret;
 }
 
-- 
1.8.0.rc1


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock()
  2012-10-15 19:06 [PATCH 1/2] Use 'inode' variable that is already dereferenced Anatol Pomozov
@ 2012-10-15 19:06 ` Anatol Pomozov
  2012-10-15 19:14   ` Anatol Pomozov
                     ` (3 more replies)
  2012-10-16  2:28 ` [PATCH 1/2] Use 'inode' variable that is already dereferenced Zheng Liu
  1 sibling, 4 replies; 9+ messages in thread
From: Anatol Pomozov @ 2012-10-15 19:06 UTC (permalink / raw)
  To: tytso, wenqing.lz, linux-ext4; +Cc: Anatol Pomozov

729f52c6be51013 introduced function ext4_get_block_write_nolock() that
is very similar to _ext4_get_block(). Eliminate code duplication
by passing different flags to _ext4_get_block()

Tested: xfs tests

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
---
 fs/ext4/inode.c | 63 ++++++++++++++++++++++-----------------------------------
 1 file changed, 24 insertions(+), 39 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b3c243b..9829c3d 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -683,7 +683,7 @@ static int _ext4_get_block(struct inode *inode, sector_t iblock,
 	map.m_lblk = iblock;
 	map.m_len = bh->b_size >> inode->i_blkbits;
 
-	if (flags && !handle) {
+	if (flags && !(flags | EXT4_GET_BLOCKS_NO_LOCK) && !handle) {
 		/* Direct IO write... */
 		if (map.m_len > DIO_MAX_BLOCKS)
 			map.m_len = DIO_MAX_BLOCKS;
@@ -880,6 +880,8 @@ static int do_journal_get_write_access(handle_t *handle,
 
 static int ext4_get_block_write(struct inode *inode, sector_t iblock,
 		   struct buffer_head *bh_result, int create);
+static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
+		   struct buffer_head *bh_result, int create);
 static int ext4_write_begin(struct file *file, struct address_space *mapping,
 			    loff_t pos, unsigned len, unsigned flags,
 			    struct page **pagep, void **fsdata)
@@ -2850,29 +2852,12 @@ static int ext4_get_block_write(struct inode *inode, sector_t iblock,
 }
 
 static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
-		   struct buffer_head *bh_result, int flags)
+		   struct buffer_head *bh_result, int create)
 {
-	handle_t *handle = ext4_journal_current_handle();
-	struct ext4_map_blocks map;
-	int ret = 0;
-
-	ext4_debug("ext4_get_block_write_nolock: inode %lu, flag %d\n",
-		   inode->i_ino, flags);
-
-	flags = EXT4_GET_BLOCKS_NO_LOCK;
-
-	map.m_lblk = iblock;
-	map.m_len = bh_result->b_size >> inode->i_blkbits;
-
-	ret = ext4_map_blocks(handle, inode, &map, flags);
-	if (ret > 0) {
-		map_bh(bh_result, inode->i_sb, map.m_pblk);
-		bh_result->b_state = (bh_result->b_state & ~EXT4_MAP_FLAGS) |
-					map.m_flags;
-		bh_result->b_size = inode->i_sb->s_blocksize * map.m_len;
-		ret = 0;
-	}
-	return ret;
+	ext4_debug("ext4_get_block_write_nolock: inode %lu, create flag %d\n",
+		   inode->i_ino, create);
+	return _ext4_get_block(inode, iblock, bh_result,
+			       EXT4_GET_BLOCKS_NO_LOCK);
 }
 
 static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
@@ -3003,6 +2988,8 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
 	loff_t final_size = offset + count;
 	if (rw == WRITE && final_size <= inode->i_size) {
 		int overwrite = 0;
+		get_block_t *get_block_func = NULL;
+		int dio_flags = 0;
 
 		BUG_ON(iocb->private == NULL);
 
@@ -3056,22 +3043,20 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
 			ext4_inode_aio_set(inode, io_end);
 		}
 
-		if (overwrite)
-			ret = __blockdev_direct_IO(rw, iocb, inode,
-						 inode->i_sb->s_bdev, iov,
-						 offset, nr_segs,
-						 ext4_get_block_write_nolock,
-						 ext4_end_io_dio,
-						 NULL,
-						 0);
-		else
-			ret = __blockdev_direct_IO(rw, iocb, inode,
-						 inode->i_sb->s_bdev, iov,
-						 offset, nr_segs,
-						 ext4_get_block_write,
-						 ext4_end_io_dio,
-						 NULL,
-						 DIO_LOCKING);
+		if (overwrite) {
+			get_block_func = ext4_get_block_write_nolock;
+		} else {
+			get_block_func = ext4_get_block_write;
+			dio_flags = DIO_LOCKING;
+		}
+		ret = __blockdev_direct_IO(rw, iocb, inode,
+					 inode->i_sb->s_bdev, iov,
+					 offset, nr_segs,
+					 get_block_func,
+					 ext4_end_io_dio,
+					 NULL,
+					 dio_flags);
+
 		if (iocb->private)
 			ext4_inode_aio_set(inode, NULL);
 		/*
-- 
1.8.0.rc1


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock()
  2012-10-15 19:06 ` [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock() Anatol Pomozov
@ 2012-10-15 19:14   ` Anatol Pomozov
  2012-10-16  2:37     ` Zheng Liu
  2012-10-16  2:36   ` Zheng Liu
                     ` (2 subsequent siblings)
  3 siblings, 1 reply; 9+ messages in thread
From: Anatol Pomozov @ 2012-10-15 19:14 UTC (permalink / raw)
  To: tytso, wenqing.lz, linux-ext4; +Cc: Anatol Pomozov

On Mon, Oct 15, 2012 at 12:06 PM, Anatol Pomozov
<anatol.pomozov@gmail.com> wrote:
> 729f52c6be51013 introduced function ext4_get_block_write_nolock() that
> is very similar to _ext4_get_block(). Eliminate code duplication
> by passing different flags to _ext4_get_block()
>
> Tested: xfs tests
>
> Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
> ---
>  fs/ext4/inode.c | 63 ++++++++++++++++++++++-----------------------------------
>  1 file changed, 24 insertions(+), 39 deletions(-)
>
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index b3c243b..9829c3d 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -683,7 +683,7 @@ static int _ext4_get_block(struct inode *inode, sector_t iblock,
>         map.m_lblk = iblock;
>         map.m_len = bh->b_size >> inode->i_blkbits;
>
> -       if (flags && !handle) {
> +       if (flags && !(flags | EXT4_GET_BLOCKS_NO_LOCK) && !handle) {
>                 /* Direct IO write... */
>                 if (map.m_len > DIO_MAX_BLOCKS)
>                         map.m_len = DIO_MAX_BLOCKS;
> @@ -880,6 +880,8 @@ static int do_journal_get_write_access(handle_t *handle,
>
>  static int ext4_get_block_write(struct inode *inode, sector_t iblock,
>                    struct buffer_head *bh_result, int create);
> +static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
> +                  struct buffer_head *bh_result, int create);
>  static int ext4_write_begin(struct file *file, struct address_space *mapping,
>                             loff_t pos, unsigned len, unsigned flags,
>                             struct page **pagep, void **fsdata)
> @@ -2850,29 +2852,12 @@ static int ext4_get_block_write(struct inode *inode, sector_t iblock,
>  }
>
>  static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
> -                  struct buffer_head *bh_result, int flags)
> +                  struct buffer_head *bh_result, int create)
>  {
> -       handle_t *handle = ext4_journal_current_handle();
> -       struct ext4_map_blocks map;
> -       int ret = 0;
> -
> -       ext4_debug("ext4_get_block_write_nolock: inode %lu, flag %d\n",
> -                  inode->i_ino, flags);
> -
> -       flags = EXT4_GET_BLOCKS_NO_LOCK;
> -
> -       map.m_lblk = iblock;
> -       map.m_len = bh_result->b_size >> inode->i_blkbits;
> -
> -       ret = ext4_map_blocks(handle, inode, &map, flags);
> -       if (ret > 0) {
> -               map_bh(bh_result, inode->i_sb, map.m_pblk);
> -               bh_result->b_state = (bh_result->b_state & ~EXT4_MAP_FLAGS) |
> -                                       map.m_flags;
> -               bh_result->b_size = inode->i_sb->s_blocksize * map.m_len;
> -               ret = 0;
> -       }
> -       return ret;
> +       ext4_debug("ext4_get_block_write_nolock: inode %lu, create flag %d\n",
> +                  inode->i_ino, create);
> +       return _ext4_get_block(inode, iblock, bh_result,
> +                              EXT4_GET_BLOCKS_NO_LOCK);
>  }
>
>  static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
> @@ -3003,6 +2988,8 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
>         loff_t final_size = offset + count;
>         if (rw == WRITE && final_size <= inode->i_size) {
>                 int overwrite = 0;
> +               get_block_t *get_block_func = NULL;
> +               int dio_flags = 0;
>
>                 BUG_ON(iocb->private == NULL);
>
> @@ -3056,22 +3043,20 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
>                         ext4_inode_aio_set(inode, io_end);
>                 }
>
> -               if (overwrite)
> -                       ret = __blockdev_direct_IO(rw, iocb, inode,
> -                                                inode->i_sb->s_bdev, iov,
> -                                                offset, nr_segs,
> -                                                ext4_get_block_write_nolock,
> -                                                ext4_end_io_dio,
> -                                                NULL,
> -                                                0);
> -               else
> -                       ret = __blockdev_direct_IO(rw, iocb, inode,
> -                                                inode->i_sb->s_bdev, iov,
> -                                                offset, nr_segs,
> -                                                ext4_get_block_write,
> -                                                ext4_end_io_dio,
> -                                                NULL,
> -                                                DIO_LOCKING);
> +               if (overwrite) {
> +                       get_block_func = ext4_get_block_write_nolock;

Ideally if block layer (function __blockdev_direct_IO) accepted some
user-data (e.g. flag) and later passed it back to callback function
(i.e. ext4_get_block_write). In this case we do not need two functions
ext4_get_block_write/ext4_get_block_write_nolock.

> +               } else {
> +                       get_block_func = ext4_get_block_write;
> +                       dio_flags = DIO_LOCKING;
> +               }
> +               ret = __blockdev_direct_IO(rw, iocb, inode,
> +                                        inode->i_sb->s_bdev, iov,
> +                                        offset, nr_segs,
> +                                        get_block_func,
> +                                        ext4_end_io_dio,
> +                                        NULL,
> +                                        dio_flags);
> +
>                 if (iocb->private)
>                         ext4_inode_aio_set(inode, NULL);
>                 /*
> --
> 1.8.0.rc1
>

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 1/2] Use 'inode' variable that is already dereferenced
  2012-10-15 19:06 [PATCH 1/2] Use 'inode' variable that is already dereferenced Anatol Pomozov
  2012-10-15 19:06 ` [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock() Anatol Pomozov
@ 2012-10-16  2:28 ` Zheng Liu
  1 sibling, 0 replies; 9+ messages in thread
From: Zheng Liu @ 2012-10-16  2:28 UTC (permalink / raw)
  To: Anatol Pomozov; +Cc: tytso, wenqing.lz, linux-ext4

On Mon, Oct 15, 2012 at 12:06:48PM -0700, Anatol Pomozov wrote:
> Tested: xfs tests
> 
> Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
> ---
>  fs/ext4/page-io.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
> index 68e896e..0fd16e6 100644
> --- a/fs/ext4/page-io.c
> +++ b/fs/ext4/page-io.c
> @@ -111,7 +111,7 @@ static int ext4_end_io(ext4_io_end_t *io)
>  		inode_dio_done(inode);
>  	/* Wake up anyone waiting on unwritten extent conversion */
>  	if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten))
> -		wake_up_all(ext4_ioend_wq(io->inode));
> +		wake_up_all(ext4_ioend_wq(inode));

Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock()
  2012-10-15 19:06 ` [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock() Anatol Pomozov
  2012-10-15 19:14   ` Anatol Pomozov
@ 2012-10-16  2:36   ` Zheng Liu
  2012-11-08 20:08   ` Theodore Ts'o
  2012-11-09 17:29   ` Theodore Ts'o
  3 siblings, 0 replies; 9+ messages in thread
From: Zheng Liu @ 2012-10-16  2:36 UTC (permalink / raw)
  To: Anatol Pomozov; +Cc: tytso, wenqing.lz, linux-ext4

On Mon, Oct 15, 2012 at 12:06:49PM -0700, Anatol Pomozov wrote:
> 729f52c6be51013 introduced function ext4_get_block_write_nolock() that
> is very similar to _ext4_get_block(). Eliminate code duplication
> by passing different flags to _ext4_get_block()
> 
> Tested: xfs tests
> 
> Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>

Good catch. you can add:
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock()
  2012-10-15 19:14   ` Anatol Pomozov
@ 2012-10-16  2:37     ` Zheng Liu
  0 siblings, 0 replies; 9+ messages in thread
From: Zheng Liu @ 2012-10-16  2:37 UTC (permalink / raw)
  To: Anatol Pomozov; +Cc: tytso, wenqing.lz, linux-ext4

On Mon, Oct 15, 2012 at 12:14:37PM -0700, Anatol Pomozov wrote:
[snip]
> Ideally if block layer (function __blockdev_direct_IO) accepted some
> user-data (e.g. flag) and later passed it back to callback function
> (i.e. ext4_get_block_write). In this case we do not need two functions
> ext4_get_block_write/ext4_get_block_write_nolock.

Thanks for teaching me. :-)

Regards,
Zheng

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock()
  2012-10-15 19:06 ` [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock() Anatol Pomozov
  2012-10-15 19:14   ` Anatol Pomozov
  2012-10-16  2:36   ` Zheng Liu
@ 2012-11-08 20:08   ` Theodore Ts'o
  2012-11-09 17:29   ` Theodore Ts'o
  3 siblings, 0 replies; 9+ messages in thread
From: Theodore Ts'o @ 2012-11-08 20:08 UTC (permalink / raw)
  To: Anatol Pomozov; +Cc: wenqing.lz, linux-ext4

On Mon, Oct 15, 2012 at 12:06:49PM -0700, Anatol Pomozov wrote:
> 729f52c6be51013 introduced function ext4_get_block_write_nolock() that
> is very similar to _ext4_get_block(). Eliminate code duplication
> by passing different flags to _ext4_get_block()
> 
> Tested: xfs tests
> 
> Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>

Applied, thanks.

					- Ted

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock()
  2012-10-15 19:06 ` [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock() Anatol Pomozov
                     ` (2 preceding siblings ...)
  2012-11-08 20:08   ` Theodore Ts'o
@ 2012-11-09 17:29   ` Theodore Ts'o
  2012-11-09 17:51     ` Anatol Pomozov
  3 siblings, 1 reply; 9+ messages in thread
From: Theodore Ts'o @ 2012-11-09 17:29 UTC (permalink / raw)
  To: Anatol Pomozov; +Cc: wenqing.lz, linux-ext4

There's a really serious bug in this patch which I didn't notice at
first:

> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -683,7 +683,7 @@ static int _ext4_get_block(struct inode *inode, sector_t iblock,
>  	map.m_lblk = iblock;
>  	map.m_len = bh->b_size >> inode->i_blkbits;
>  
> -	if (flags && !handle) {
> +	if (flags && !(flags | EXT4_GET_BLOCKS_NO_LOCK) && !handle) {
                            ^^^

This should obviously read:

	if (flags && !(flags & EXT4_GET_BLOCKS_NO_LOCK) && !handle) {

Otherwise xfstests #91 will blow out with a circular lockdep warning.

As a reminder, please do make sure you compile with lockdep enabled
when you run your tests; it's found more than one bug for me!

     	     	  	      	    	      - Ted

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock()
  2012-11-09 17:29   ` Theodore Ts'o
@ 2012-11-09 17:51     ` Anatol Pomozov
  0 siblings, 0 replies; 9+ messages in thread
From: Anatol Pomozov @ 2012-11-09 17:51 UTC (permalink / raw)
  To: Theodore Ts'o; +Cc: wenqing.lz, linux-ext4

Hi

On Fri, Nov 9, 2012 at 9:29 AM, Theodore Ts'o <tytso@mit.edu> wrote:
> There's a really serious bug in this patch which I didn't notice at
> first:
>
>> --- a/fs/ext4/inode.c
>> +++ b/fs/ext4/inode.c
>> @@ -683,7 +683,7 @@ static int _ext4_get_block(struct inode *inode, sector_t iblock,
>>       map.m_lblk = iblock;
>>       map.m_len = bh->b_size >> inode->i_blkbits;
>>
>> -     if (flags && !handle) {
>> +     if (flags && !(flags | EXT4_GET_BLOCKS_NO_LOCK) && !handle) {
>                             ^^^
>
> This should obviously read:
>
>         if (flags && !(flags & EXT4_GET_BLOCKS_NO_LOCK) && !handle) {

D'oh... You are right..

> Otherwise xfstests #91 will blow out with a circular lockdep warning.
>
> As a reminder, please do make sure you compile with lockdep enabled
> when you run your tests; it's found more than one bug for me!

I though I tested with and without debug options enabled. Maybe I
missed lockdep option somehow, next time i'll make sure that it is
enabled.

Thanks for catching it.

>
>                                               - Ted

^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2012-11-09 17:51 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-10-15 19:06 [PATCH 1/2] Use 'inode' variable that is already dereferenced Anatol Pomozov
2012-10-15 19:06 ` [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock() Anatol Pomozov
2012-10-15 19:14   ` Anatol Pomozov
2012-10-16  2:37     ` Zheng Liu
2012-10-16  2:36   ` Zheng Liu
2012-11-08 20:08   ` Theodore Ts'o
2012-11-09 17:29   ` Theodore Ts'o
2012-11-09 17:51     ` Anatol Pomozov
2012-10-16  2:28 ` [PATCH 1/2] Use 'inode' variable that is already dereferenced Zheng Liu

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