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* LTP: diotest4.c:476: read to read-only space. returns 0: Success
@ 2019-11-07 13:59 Naresh Kamboju
  2019-11-08  0:20 ` Jan Stancek
  0 siblings, 1 reply; 10+ messages in thread
From: Naresh Kamboju @ 2019-11-07 13:59 UTC (permalink / raw)
  To: LTP List, Linux-Next Mailing List, linux-fsdevel
  Cc: Jan Stancek, chrubis, open list, Al Viro, Mark Brown,
	Arnd Bergmann, lkft-triage

LTP test case dio04 test failed on 32bit kernel running linux next
20191107 kernel.
Linux version 5.4.0-rc6-next-20191107.

diotest4    1  TPASS  :  Negative Offset
diotest4    2  TPASS  :  removed
diotest4    3  TPASS  :  Odd count of read and write
diotest4    4  TPASS  :  Read beyond the file size
diotest4    5  TPASS  :  Invalid file descriptor
diotest4    6  TPASS  :  Out of range file descriptor
diotest4    7  TPASS  :  Closed file descriptor
diotest4    8  TPASS  :  removed
diotest4    9  TCONF  :  diotest4.c:345: Direct I/O on /dev/null is
not supported
diotest4   10  TPASS  :  read, write to a mmaped file
diotest4   11  TPASS  :  read, write to an unmapped file
diotest4   12  TPASS  :  read from file not open for reading
diotest4   13  TPASS  :  write to file not open for writing
diotest4   14  TPASS  :  read, write with non-aligned buffer
diotest4   15  TFAIL  :  diotest4.c:476: read to read-only space.
returns 0: Success
diotest4   16  TFAIL  :  diotest4.c:180: read, write buffer in read-only space
diotest4   17  TFAIL  :  diotest4.c:114: read allows  nonexistant
space. returns 0: Success
diotest4   18  TFAIL  :  diotest4.c:129: write allows  nonexistant
space.returns -1: Invalid argument
diotest4   19  TFAIL  :  diotest4.c:180: read, write in non-existant space
diotest4   20  TPASS  :  read, write for file with O_SYNC
diotest4    0  TINFO  :  2/15 test blocks failed

Test results comparison link,
https://qa-reports.linaro.org/lkft/linux-next-oe/tests/ltp-dio-tests/dio04

Test case source link,
https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/io/direct_io/diotest4.c

Test case description:

* NAME
* diotest4.c
*
* DESCRIPTION
* The program generates error conditions and verifies the error
* code generated with the expected error value. The program also
* tests some of the boundary condtions. The size of test file created
* is filesize_in_blocks * 4k.
* Test blocks:
* [1] Negative Offset
* [2] Negative count - removed 08/01/2003 - robbiew
* [3] Odd count of read and write
* [4] Read beyond the file size
* [5] Invalid file descriptor
* [6] Out of range file descriptor
* [7] Closed file descriptor
* [8] Directory read, write - removed 10/7/2002 - plars
* [9] Character device (/dev/null) read, write
* [10] read, write to a mmaped file
* [11] read, write to an unmaped file with munmap
* [12] read from file not open for reading
* [13] write to file not open for writing
* [14] read, write with non-aligned buffer
* [15] read, write buffer in read-only space
* [16] read, write in non-existant space
* [17] read, write for file with O_SYNC

metadata:
  git branch: master
  git repo: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
  git commit: c68c5373c504078cc0e0edc7d5c88b47ca308144
  git describe: next-20191107
  make_kernelversion: 5.4.0-rc6
  kernel-config:
http://snapshots.linaro.org/openembedded/lkft/lkft/sumo/intel-core2-32/lkft/linux-next/641/config
  build-location:
http://snapshots.linaro.org/openembedded/lkft/lkft/sumo/intel-core2-32/lkft/linux-next/641

Best regards
Naresh Kamboju

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: LTP: diotest4.c:476: read to read-only space. returns 0: Success
  2019-11-07 13:59 LTP: diotest4.c:476: read to read-only space. returns 0: Success Naresh Kamboju
@ 2019-11-08  0:20 ` Jan Stancek
  2019-11-11  1:26   ` Darrick J. Wong
  0 siblings, 1 reply; 10+ messages in thread
From: Jan Stancek @ 2019-11-08  0:20 UTC (permalink / raw)
  To: Naresh Kamboju, darrick.wong
  Cc: LTP List, Linux-Next Mailing List, linux-fsdevel, chrubis,
	open list, Al Viro, Mark Brown, Arnd Bergmann, lkft-triage



----- Original Message -----
> LTP test case dio04 test failed on 32bit kernel running linux next
> 20191107 kernel.
> Linux version 5.4.0-rc6-next-20191107.
> 
> diotest4    1  TPASS  :  Negative Offset
> diotest4    2  TPASS  :  removed
> diotest4    3  TPASS  :  Odd count of read and write
> diotest4    4  TPASS  :  Read beyond the file size
> diotest4    5  TPASS  :  Invalid file descriptor
> diotest4    6  TPASS  :  Out of range file descriptor
> diotest4    7  TPASS  :  Closed file descriptor
> diotest4    8  TPASS  :  removed
> diotest4    9  TCONF  :  diotest4.c:345: Direct I/O on /dev/null is
> not supported
> diotest4   10  TPASS  :  read, write to a mmaped file
> diotest4   11  TPASS  :  read, write to an unmapped file
> diotest4   12  TPASS  :  read from file not open for reading
> diotest4   13  TPASS  :  write to file not open for writing
> diotest4   14  TPASS  :  read, write with non-aligned buffer
> diotest4   15  TFAIL  :  diotest4.c:476: read to read-only space.
> returns 0: Success
> diotest4   16  TFAIL  :  diotest4.c:180: read, write buffer in read-only
> space
> diotest4   17  TFAIL  :  diotest4.c:114: read allows  nonexistant
> space. returns 0: Success
> diotest4   18  TFAIL  :  diotest4.c:129: write allows  nonexistant
> space.returns -1: Invalid argument
> diotest4   19  TFAIL  :  diotest4.c:180: read, write in non-existant space
> diotest4   20  TPASS  :  read, write for file with O_SYNC
> diotest4    0  TINFO  :  2/15 test blocks failed

Smaller reproducer for 32-bit system and ext4 is:
  openat(AT_FDCWD, "testdata-4.5918", O_RDWR|O_DIRECT) = 4
  mmap2(NULL, 4096, PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f7b000
  read(4, 0xb7f7b000, 4096)              = 0 // expects -EFAULT

Problem appears to be conversion in ternary operator at
iomap_dio_bio_actor() return. Test passes for me with
following tweak:

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 2f88d64c2a4d..8615b1f78389 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -318,7 +318,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
                if (pad)
                        iomap_dio_zero(dio, iomap, pos, fs_block_size - pad);
        }
-       return copied ? copied : ret;
+       return copied ? (loff_t) copied : ret;
 }

 static loff_t


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: LTP: diotest4.c:476: read to read-only space. returns 0: Success
  2019-11-08  0:20 ` Jan Stancek
@ 2019-11-11  1:26   ` Darrick J. Wong
  2019-11-11  8:19     ` Jan Stancek
  0 siblings, 1 reply; 10+ messages in thread
From: Darrick J. Wong @ 2019-11-11  1:26 UTC (permalink / raw)
  To: Jan Stancek
  Cc: Naresh Kamboju, LTP List, Linux-Next Mailing List, linux-fsdevel,
	chrubis, open list, Al Viro, Mark Brown, Arnd Bergmann,
	lkft-triage, Christoph Hellwig, linux-ext4, Theodore Ts'o

[add the other iomap maintainer to cc]
[add the ext4 list to cc since they just added iomap directio support]
[add the ext4 maintainer for the same reason]

On Thu, Nov 07, 2019 at 07:20:43PM -0500, Jan Stancek wrote:
> 
> 
> ----- Original Message -----
> > LTP test case dio04 test failed on 32bit kernel running linux next
> > 20191107 kernel.
> > Linux version 5.4.0-rc6-next-20191107.
> > 
> > diotest4    1  TPASS  :  Negative Offset
> > diotest4    2  TPASS  :  removed
> > diotest4    3  TPASS  :  Odd count of read and write
> > diotest4    4  TPASS  :  Read beyond the file size
> > diotest4    5  TPASS  :  Invalid file descriptor
> > diotest4    6  TPASS  :  Out of range file descriptor
> > diotest4    7  TPASS  :  Closed file descriptor
> > diotest4    8  TPASS  :  removed
> > diotest4    9  TCONF  :  diotest4.c:345: Direct I/O on /dev/null is
> > not supported
> > diotest4   10  TPASS  :  read, write to a mmaped file
> > diotest4   11  TPASS  :  read, write to an unmapped file
> > diotest4   12  TPASS  :  read from file not open for reading
> > diotest4   13  TPASS  :  write to file not open for writing
> > diotest4   14  TPASS  :  read, write with non-aligned buffer
> > diotest4   15  TFAIL  :  diotest4.c:476: read to read-only space.
> > returns 0: Success
> > diotest4   16  TFAIL  :  diotest4.c:180: read, write buffer in read-only
> > space
> > diotest4   17  TFAIL  :  diotest4.c:114: read allows  nonexistant
> > space. returns 0: Success
> > diotest4   18  TFAIL  :  diotest4.c:129: write allows  nonexistant
> > space.returns -1: Invalid argument
> > diotest4   19  TFAIL  :  diotest4.c:180: read, write in non-existant space
> > diotest4   20  TPASS  :  read, write for file with O_SYNC
> > diotest4    0  TINFO  :  2/15 test blocks failed
> 
> Smaller reproducer for 32-bit system and ext4 is:
>   openat(AT_FDCWD, "testdata-4.5918", O_RDWR|O_DIRECT) = 4
>   mmap2(NULL, 4096, PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f7b000
>   read(4, 0xb7f7b000, 4096)              = 0 // expects -EFAULT
> 
> Problem appears to be conversion in ternary operator at
> iomap_dio_bio_actor() return. Test passes for me with
> following tweak:

I can't do a whole lot with a code snippet that lacks a proper SOB
header.

> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 2f88d64c2a4d..8615b1f78389 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -318,7 +318,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
>                 if (pad)
>                         iomap_dio_zero(dio, iomap, pos, fs_block_size - pad);
>         }
> -       return copied ? copied : ret;
> +       return copied ? (loff_t) copied : ret;

I'm a little confused on this proposed fix -- why does casting size_t
(aka unsigned long) to loff_t (long long) on a 32-bit system change the
test outcome?  Does this same diotest4 failure happen with XFS?  I ask
because XFS has been using iomap for directio for ages.

AFAICT @copied is a simple byte counter, and the other variable @n that
gets added to @copied is also a simple byte counter -- nobody should
ever be trying to stuff a negative value in there?

(Or is this a bug with the ext4 code that calls iomap_dio_rw?)

--D

>  }
> 
>  static loff_t
> 

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: LTP: diotest4.c:476: read to read-only space. returns 0: Success
  2019-11-11  1:26   ` Darrick J. Wong
@ 2019-11-11  8:19     ` Jan Stancek
  2019-11-11  8:38       ` Christoph Hellwig
  0 siblings, 1 reply; 10+ messages in thread
From: Jan Stancek @ 2019-11-11  8:19 UTC (permalink / raw)
  To: Darrick J. Wong
  Cc: Naresh Kamboju, LTP List, Linux-Next Mailing List, linux-fsdevel,
	chrubis, open list, Al Viro, Mark Brown, Arnd Bergmann,
	lkft-triage, Christoph Hellwig, linux-ext4, Theodore Ts'o


----- Original Message -----
> I can't do a whole lot with a code snippet that lacks a proper SOB
> header.

I'll resend as a patch, maybe split it to 2 returns instead.

> > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> > index 2f88d64c2a4d..8615b1f78389 100644
> > --- a/fs/iomap/direct-io.c
> > +++ b/fs/iomap/direct-io.c
> > @@ -318,7 +318,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos,
> > loff_t length,
> >                 if (pad)
> >                         iomap_dio_zero(dio, iomap, pos, fs_block_size -
> >                         pad);
> >         }
> > -       return copied ? copied : ret;
> > +       return copied ? (loff_t) copied : ret;
> 
> I'm a little confused on this proposed fix -- why does casting size_t
> (aka unsigned long) to loff_t (long long) on a 32-bit system change the
> test outcome?

Ternary operator has a return type and an attempt is made to convert
each of operands to the type of the other. So, in this case "ret"
appears to be converted to type of "copied" first. Both have size of
4 bytes on 32-bit x86:

size_t copied = 0;
int ret = -14;
long long actor_ret = copied ? copied : ret;

On x86_64: actor_ret == -14;
On x86   : actor_ret == 4294967282

> Does this same diotest4 failure happen with XFS?  I ask
> because XFS has been using iomap for directio for ages.

Yes, it fails on XFS too.


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: LTP: diotest4.c:476: read to read-only space. returns 0: Success
  2019-11-11  8:19     ` Jan Stancek
@ 2019-11-11  8:38       ` Christoph Hellwig
  2019-11-11 10:28         ` [PATCH] iomap: fix return value of iomap_dio_bio_actor on 32bit systems Jan Stancek
  2019-11-11 10:38         ` LTP: diotest4.c:476: read to read-only space. returns 0: Success Jan Stancek
  0 siblings, 2 replies; 10+ messages in thread
From: Christoph Hellwig @ 2019-11-11  8:38 UTC (permalink / raw)
  To: Jan Stancek
  Cc: Darrick J. Wong, Naresh Kamboju, LTP List,
	Linux-Next Mailing List, linux-fsdevel, chrubis, open list,
	Al Viro, Mark Brown, Arnd Bergmann, lkft-triage,
	Christoph Hellwig, linux-ext4, Theodore Ts'o

On Mon, Nov 11, 2019 at 03:19:40AM -0500, Jan Stancek wrote:
> > > loff_t length,
> > >                 if (pad)
> > >                         iomap_dio_zero(dio, iomap, pos, fs_block_size -
> > >                         pad);
> > >         }
> > > -       return copied ? copied : ret;
> > > +       return copied ? (loff_t) copied : ret;
> > 
> > I'm a little confused on this proposed fix -- why does casting size_t
> > (aka unsigned long) to loff_t (long long) on a 32-bit system change the
> > test outcome?
> 
> Ternary operator has a return type and an attempt is made to convert
> each of operands to the type of the other. So, in this case "ret"
> appears to be converted to type of "copied" first. Both have size of
> 4 bytes on 32-bit x86:

Sounds like we should use a good old if here to avoid that whole problem
spacE:

	if (copied)
		return copied;
	return ret;

> size_t copied = 0;
> int ret = -14;
> long long actor_ret = copied ? copied : ret;
> 
> On x86_64: actor_ret == -14;
> On x86   : actor_ret == 4294967282
> 
> > Does this same diotest4 failure happen with XFS?  I ask
> > because XFS has been using iomap for directio for ages.
> 
> Yes, it fails on XFS too.

Is this a new test?  If not why was this never reported?  Sounds like
we should add this test case to xfstests.

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH] iomap: fix return value of iomap_dio_bio_actor on 32bit systems
  2019-11-11  8:38       ` Christoph Hellwig
@ 2019-11-11 10:28         ` Jan Stancek
  2019-11-11 10:36           ` Christoph Hellwig
  2019-11-12  1:24           ` Darrick J. Wong
  2019-11-11 10:38         ` LTP: diotest4.c:476: read to read-only space. returns 0: Success Jan Stancek
  1 sibling, 2 replies; 10+ messages in thread
From: Jan Stancek @ 2019-11-11 10:28 UTC (permalink / raw)
  To: darrick.wong, naresh.kamboju, hch
  Cc: ltp, linux-next, linux-fsdevel, chrubis, linux-kernel, viro,
	broonie, arnd, lkft-triage, linux-ext4, tytso, jstancek

Naresh reported LTP diotest4 failing for 32bit x86 and arm -next
kernels on ext4. Same problem exists in 5.4-rc7 on xfs.

The failure comes down to:
  openat(AT_FDCWD, "testdata-4.5918", O_RDWR|O_DIRECT) = 4
  mmap2(NULL, 4096, PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f7b000
  read(4, 0xb7f7b000, 4096)              = 0 // expects -EFAULT

Problem is conversion at iomap_dio_bio_actor() return. Ternary
operator has a return type and an attempt is made to convert each
of operands to the type of the other. In this case "ret" (int)
is converted to type of "copied" (unsigned long). Both have size
of 4 bytes:
    size_t copied = 0;
    int ret = -14;
    long long actor_ret = copied ? copied : ret;

    On x86_64: actor_ret == -14;
    On x86   : actor_ret == 4294967282

Replace ternary operator with 2 return statements to avoid this
unwanted conversion.

Fixes: 4721a6010990 ("iomap: dio data corruption and spurious errors when pipes fill")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Jan Stancek <jstancek@redhat.com>
---
 fs/iomap/direct-io.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 1fc28c2da279..7c58f51d7da7 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -318,7 +318,9 @@ static void iomap_dio_bio_end_io(struct bio *bio)
 		if (pad)
 			iomap_dio_zero(dio, iomap, pos, fs_block_size - pad);
 	}
-	return copied ? copied : ret;
+	if (copied)
+		return copied;
+	return ret;
 }
 
 static loff_t
-- 
1.8.3.1


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH] iomap: fix return value of iomap_dio_bio_actor on 32bit systems
  2019-11-11 10:28         ` [PATCH] iomap: fix return value of iomap_dio_bio_actor on 32bit systems Jan Stancek
@ 2019-11-11 10:36           ` Christoph Hellwig
  2019-11-12  1:24           ` Darrick J. Wong
  1 sibling, 0 replies; 10+ messages in thread
From: Christoph Hellwig @ 2019-11-11 10:36 UTC (permalink / raw)
  To: Jan Stancek
  Cc: darrick.wong, naresh.kamboju, hch, ltp, linux-next,
	linux-fsdevel, chrubis, linux-kernel, viro, broonie, arnd,
	lkft-triage, linux-ext4, tytso

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: LTP: diotest4.c:476: read to read-only space. returns 0: Success
  2019-11-11  8:38       ` Christoph Hellwig
  2019-11-11 10:28         ` [PATCH] iomap: fix return value of iomap_dio_bio_actor on 32bit systems Jan Stancek
@ 2019-11-11 10:38         ` Jan Stancek
  2019-11-11 18:26           ` Naresh Kamboju
  1 sibling, 1 reply; 10+ messages in thread
From: Jan Stancek @ 2019-11-11 10:38 UTC (permalink / raw)
  To: Christoph Hellwig
  Cc: Darrick J. Wong, Naresh Kamboju, LTP List,
	Linux-Next Mailing List, linux-fsdevel, chrubis, open list,
	Al Viro, Mark Brown, Arnd Bergmann, lkft-triage, linux-ext4,
	Theodore Ts'o


----- Original Message -----
> Is this a new test?

No, it's not new.

> If not why was this never reported?  Sounds like
> we should add this test case to xfstests.

I'm guessing not that many users still run 32bit kernels.
Naresh' setup is using ext4, so I assume he noticed only
after recent changes in linux-next wrt. directio and ext4.

Regards,
Jan


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: LTP: diotest4.c:476: read to read-only space. returns 0: Success
  2019-11-11 10:38         ` LTP: diotest4.c:476: read to read-only space. returns 0: Success Jan Stancek
@ 2019-11-11 18:26           ` Naresh Kamboju
  0 siblings, 0 replies; 10+ messages in thread
From: Naresh Kamboju @ 2019-11-11 18:26 UTC (permalink / raw)
  To: Jan Stancek
  Cc: Christoph Hellwig, Darrick J. Wong, LTP List,
	Linux-Next Mailing List, linux-fsdevel, chrubis, open list,
	Al Viro, Mark Brown, Arnd Bergmann, lkft-triage, linux-ext4,
	Theodore Ts'o

On Mon, 11 Nov 2019 at 16:09, Jan Stancek <jstancek@redhat.com> wrote:
>
>
> ----- Original Message -----
> > Is this a new test?
>
> No, it's not new.
>
> > If not why was this never reported?  Sounds like
> > we should add this test case to xfstests.
>
> I'm guessing not that many users still run 32bit kernels.
> Naresh' setup is using ext4, so I assume he noticed only
> after recent changes in linux-next wrt. directio and ext4.

That's true.
Started noticing recently from Linux next-20191107 kernel on i386 and arm32.

Steps to reproduce:
./runltp -f dio -d /mounted-ext4-drive

- Naresh

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH] iomap: fix return value of iomap_dio_bio_actor on 32bit systems
  2019-11-11 10:28         ` [PATCH] iomap: fix return value of iomap_dio_bio_actor on 32bit systems Jan Stancek
  2019-11-11 10:36           ` Christoph Hellwig
@ 2019-11-12  1:24           ` Darrick J. Wong
  1 sibling, 0 replies; 10+ messages in thread
From: Darrick J. Wong @ 2019-11-12  1:24 UTC (permalink / raw)
  To: Jan Stancek
  Cc: naresh.kamboju, hch, ltp, linux-next, linux-fsdevel, chrubis,
	linux-kernel, viro, broonie, arnd, lkft-triage, linux-ext4,
	tytso

On Mon, Nov 11, 2019 at 11:28:10AM +0100, Jan Stancek wrote:
> Naresh reported LTP diotest4 failing for 32bit x86 and arm -next
> kernels on ext4. Same problem exists in 5.4-rc7 on xfs.
> 
> The failure comes down to:
>   openat(AT_FDCWD, "testdata-4.5918", O_RDWR|O_DIRECT) = 4
>   mmap2(NULL, 4096, PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f7b000
>   read(4, 0xb7f7b000, 4096)              = 0 // expects -EFAULT
> 
> Problem is conversion at iomap_dio_bio_actor() return. Ternary
> operator has a return type and an attempt is made to convert each
> of operands to the type of the other. In this case "ret" (int)
> is converted to type of "copied" (unsigned long). Both have size
> of 4 bytes:
>     size_t copied = 0;
>     int ret = -14;
>     long long actor_ret = copied ? copied : ret;
> 
>     On x86_64: actor_ret == -14;
>     On x86   : actor_ret == 4294967282
> 
> Replace ternary operator with 2 return statements to avoid this
> unwanted conversion.
> 
> Fixes: 4721a6010990 ("iomap: dio data corruption and spurious errors when pipes fill")
> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
> Signed-off-by: Jan Stancek <jstancek@redhat.com>

Thansk for the full explanation & patch, will test...

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
>  fs/iomap/direct-io.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 1fc28c2da279..7c58f51d7da7 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -318,7 +318,9 @@ static void iomap_dio_bio_end_io(struct bio *bio)
>  		if (pad)
>  			iomap_dio_zero(dio, iomap, pos, fs_block_size - pad);
>  	}
> -	return copied ? copied : ret;
> +	if (copied)
> +		return copied;
> +	return ret;
>  }
>  
>  static loff_t
> -- 
> 1.8.3.1
> 

^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, back to index

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-11-07 13:59 LTP: diotest4.c:476: read to read-only space. returns 0: Success Naresh Kamboju
2019-11-08  0:20 ` Jan Stancek
2019-11-11  1:26   ` Darrick J. Wong
2019-11-11  8:19     ` Jan Stancek
2019-11-11  8:38       ` Christoph Hellwig
2019-11-11 10:28         ` [PATCH] iomap: fix return value of iomap_dio_bio_actor on 32bit systems Jan Stancek
2019-11-11 10:36           ` Christoph Hellwig
2019-11-12  1:24           ` Darrick J. Wong
2019-11-11 10:38         ` LTP: diotest4.c:476: read to read-only space. returns 0: Success Jan Stancek
2019-11-11 18:26           ` Naresh Kamboju

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