2012-03-30 15:44:33

by Dave Kleikamp

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Subject: [RFC PATCH v2 18/21] ext4: add support for read_iter and write_iter

use the generic .read_iter and .write_iter functions

Signed-off-by: Dave Kleikamp <[email protected]>
Cc: Zach Brown <[email protected]>
Cc: "Theodore Ts'o" <[email protected]>
Cc: Andreas Dilger <[email protected]>
Cc: [email protected]
---
fs/ext4/file.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index cb70f18..ce76745 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -234,6 +234,8 @@ const struct file_operations ext4_file_operations = {
.write = do_sync_write,
.aio_read = generic_file_aio_read,
.aio_write = ext4_file_write,
+ .read_iter = generic_file_read_iter,
+ .write_iter = generic_file_write_iter,
.unlocked_ioctl = ext4_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = ext4_compat_ioctl,
--
1.7.9.5



2012-04-02 18:42:07

by Theodore Ts'o

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Subject: Re: [RFC PATCH v2 18/21] ext4: add support for read_iter and write_iter

On Fri, Mar 30, 2012 at 10:43:45AM -0500, Dave Kleikamp wrote:
> use the generic .read_iter and .write_iter functions

Potentially silly question --- why not use NULL pointer to mean
generic_file_read_iter and generic_file_write_iter? Then you won't
have to patch a bunch of file systems to add the generic .read_iter
and .write_iter?

- Ted

2012-04-02 22:45:26

by Dave Kleikamp

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Subject: Re: [RFC PATCH v2 18/21] ext4: add support for read_iter and write_iter

On 04/02/2012 01:42 PM, Ted Ts'o wrote:
> On Fri, Mar 30, 2012 at 10:43:45AM -0500, Dave Kleikamp wrote:
>> use the generic .read_iter and .write_iter functions
>
> Potentially silly question --- why not use NULL pointer to mean
> generic_file_read_iter and generic_file_write_iter? Then you won't
> have to patch a bunch of file systems to add the generic .read_iter
> and .write_iter?

I'm not very confident that generic_file_read_iter and
generic_file_write_iter will work for every filesystem that I haven't
yet touched. It should work if they use generic_aio_read and _write, but
some have their own versions of those.

Shaggy

2012-04-03 00:11:37

by Dave Kleikamp

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Subject: Re: [RFC PATCH v2 18/21] ext4: add support for read_iter and write_iter

On 04/02/2012 05:45 PM, Dave Kleikamp wrote:
> On 04/02/2012 01:42 PM, Ted Ts'o wrote:
>> On Fri, Mar 30, 2012 at 10:43:45AM -0500, Dave Kleikamp wrote:
>>> use the generic .read_iter and .write_iter functions
>>
>> Potentially silly question --- why not use NULL pointer to mean
>> generic_file_read_iter and generic_file_write_iter? Then you won't
>> have to patch a bunch of file systems to add the generic .read_iter
>> and .write_iter?
>
> I'm not very confident that generic_file_read_iter and
> generic_file_write_iter will work for every filesystem that I haven't
> yet touched. It should work if they use generic_aio_read and _write, but
> some have their own versions of those.

In fact, I just realized a big oversight on my part in that I have ext4
calling generic_file_write_iter(), when in fact, it should be doing the
equivalent of ext4_file_write(). If been chasing a bug assuming that
ext4 called generic_aio_write(). Sometimes I miss the obvious.

>
> Shaggy