Re: [PATCH 7/6] fat: Support a truncate() for expanding size

Andrew Morton <[email protected]> writes:

> OGAWA Hirofumi <[email protected]> wrote:
>>
>> +static int fat_cont_expand(struct inode *inode, loff_t size)
>
> Is it not possible to extend generic_cont_expand() so that fatfs can use it?

The generic_cont_expand() is too generic.

If "size" is block boundary, generic_cont_expand() expands the
->i_size to "size + 1", after it, the caller of it will truncate to
"size" by vmtruncate().

This sequence is not need if ->prepare_write() is cont_prepare_write().
The cont_prepare_write() will just fill the blocks with zero until
"size" if blocks is not allocated yet.

FAT is using cont_parepare_write(), so for avoiding the above extra
work, is using own version.

Probably, this version is generic only for cont_parepare_write().

Thanks.
-- 
OGAWA Hirofumi <[email protected]>
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Follow-Ups:
- Re: [PATCH 7/6] fat: Support a truncate() for expanding size
  - From: Andrew Morton <[email protected]>

References:
- [PATCH 1/6] fat: move fat_clusters_flush() to write_super()
  - From: OGAWA Hirofumi <[email protected]>
- [PATCH] fat: use sb_find_get_block() instead of sb_getblk()
  - From: OGAWA Hirofumi <[email protected]>
- [PATCH 3/6] fat: add the read/writepages()
  - From: OGAWA Hirofumi <[email protected]>
- [PATCH 4/6] fat: s/EXPORT_SYMBOL/EXPORT_SYMBOL_GPL/
  - From: OGAWA Hirofumi <[email protected]>
- [PATCH 5/6] fat: support ->direct_IO()
  - From: OGAWA Hirofumi <[email protected]>
- [PATCH 6/6] export/change sync_page_range/_nolock()
  - From: OGAWA Hirofumi <[email protected]>
- [PATCH 7/6] fat: Support a truncate() for expanding size
  - From: OGAWA Hirofumi <[email protected]>
- Re: [PATCH 7/6] fat: Support a truncate() for expanding size
  - From: Andrew Morton <[email protected]>

Prev by Date: [OT] Re: [PATCH 3/18] allow callers of seq_open do allocation themselves
Next by Date: Re: Am I thinking correctly?
Previous by thread: Re: [PATCH 7/6] fat: Support a truncate() for expanding size
Next by thread: Re: [PATCH 7/6] fat: Support a truncate() for expanding size
Index(es):
- Date
- Thread

[Index of Archives] [Kernel Newbies] [Netfilter] [Bugtraq] [Photo] [Stuff] [Gimp] [Yosemite News] [MIPS Linux] [ARM Linux] [Linux Security] [Linux RAID] [Video 4 Linux] [Linux for the blind] [Linux Resources]