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* ext4: delayed allocation support and mmap
@ 2011-08-17 11:02 Surbhi Palande
  2011-08-17 11:49 ` Jan Kara
  0 siblings, 1 reply; 3+ messages in thread
From: Surbhi Palande @ 2011-08-17 11:02 UTC (permalink / raw)
  To: linux-ext4; +Cc: Jan Kara, Ted Tso

Hi All,

Current ext4_page_mkwrite() implementation always allocates a block
through  ext4_get_block_write() or ext4_get_block().

Commit: 9ea7df534ed2a18157434a496a12cf073ca00c52 removed the calls to
write_begin() to avoid calling ext4_da_write_begin() as calling it
from here is racy.

So for now, in ext4: delayed allocation is not supported under an mmap call?

Regards,
Surbhi.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: ext4: delayed allocation support and mmap
  2011-08-17 11:02 ext4: delayed allocation support and mmap Surbhi Palande
@ 2011-08-17 11:49 ` Jan Kara
  2011-08-17 11:53   ` Surbhi Palande
  0 siblings, 1 reply; 3+ messages in thread
From: Jan Kara @ 2011-08-17 11:49 UTC (permalink / raw)
  To: Surbhi Palande; +Cc: linux-ext4, Jan Kara, Ted Tso

  Hi,

On Wed 17-08-11 14:02:09, Surbhi Palande wrote:
> Current ext4_page_mkwrite() implementation always allocates a block
> through  ext4_get_block_write() or ext4_get_block().
  Why do you think so? Look at:
        /* Delalloc case is easy... */
        if (test_opt(inode->i_sb, DELALLOC) &&
            !ext4_should_journal_data(inode) &&
            !ext4_nonda_switch(inode->i_sb)) {
                do {
                        ret = __block_page_mkwrite(vma, vmf,
                                                   ext4_da_get_block_prep);
                } while (ret == -ENOSPC &&
                       ext4_should_retry_alloc(inode->i_sb, &retries));
                goto out_ret;
        }

								Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: ext4: delayed allocation support and mmap
  2011-08-17 11:49 ` Jan Kara
@ 2011-08-17 11:53   ` Surbhi Palande
  0 siblings, 0 replies; 3+ messages in thread
From: Surbhi Palande @ 2011-08-17 11:53 UTC (permalink / raw)
  To: Jan Kara; +Cc: linux-ext4, Ted Tso

On Wed, Aug 17, 2011 at 2:49 PM, Jan Kara <jack@suse.cz> wrote:
>  Hi,
>
> On Wed 17-08-11 14:02:09, Surbhi Palande wrote:
>> Current ext4_page_mkwrite() implementation always allocates a block
>> through  ext4_get_block_write() or ext4_get_block().
>  Why do you think so? Look at:
>        /* Delalloc case is easy... */
>        if (test_opt(inode->i_sb, DELALLOC) &&
>            !ext4_should_journal_data(inode) &&
>            !ext4_nonda_switch(inode->i_sb)) {
>                do {
>                        ret = __block_page_mkwrite(vma, vmf,
>                                                   ext4_da_get_block_prep);
>                } while (ret == -ENOSPC &&
>                       ext4_should_retry_alloc(inode->i_sb, &retries));
>                goto out_ret;
>        }

Oops! Sorry about that :(

Regards,
Surbhi.




>
>                                                                Honza
> --
> Jan Kara <jack@suse.cz>
> SUSE Labs, CR
>
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^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2011-08-17 11:53 UTC | newest]

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2011-08-17 11:02 ext4: delayed allocation support and mmap Surbhi Palande
2011-08-17 11:49 ` Jan Kara
2011-08-17 11:53   ` Surbhi Palande

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