2013-10-09 14:40:37

by Namjae Jeon

[permalink] [raw]
Subject: [PATCH 1/5] fat: add i_disksize to represent uninitialized size

From: Namjae Jeon <[email protected]>

Add i_disksize to represent uninitialized allocated size.
And mmu_private represent initialized allocated size.

Signed-off-by: Namjae Jeon <[email protected]>
Signed-off-by: Amit Sahrawat <[email protected]>
---
fs/fat/cache.c | 4 ++--
fs/fat/fat.h | 3 ++-
fs/fat/file.c | 4 +++-
fs/fat/inode.c | 4 ++++
4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/fs/fat/cache.c b/fs/fat/cache.c
index 91ad9e1..37572c2 100644
--- a/fs/fat/cache.c
+++ b/fs/fat/cache.c
@@ -329,10 +329,10 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
return 0;

/*
- * ->mmu_private can access on only allocation path.
+ * ->i_disksize can access on only allocation path.
* (caller must hold ->i_mutex)
*/
- last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1))
+ last_block = (MSDOS_I(inode)->i_disksize + (blocksize - 1))
>> blocksize_bits;
if (sector >= last_block)
return 0;
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 4241e6f..1716199 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -117,7 +117,8 @@ struct msdos_inode_info {
unsigned int cache_valid_id;

/* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
- loff_t mmu_private; /* physically allocated size */
+ loff_t mmu_private; /* physically allocated size (uninitialized) */
+ loff_t i_disksize; /* physically allocated size (initialized) */

int i_start; /* first cluster or 0 */
int i_logstart; /* logical first cluster */
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 33711ff..7301adb 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -300,8 +300,10 @@ void fat_truncate_blocks(struct inode *inode, loff_t offset)
* This protects against truncating a file bigger than it was then
* trying to write into the hole.
*/
- if (MSDOS_I(inode)->mmu_private > offset)
+ if (MSDOS_I(inode)->mmu_private > offset) {
MSDOS_I(inode)->mmu_private = offset;
+ MSDOS_I(inode)->i_disksize = offset;
+ }

nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits;

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 3134d1e..578a5db 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -93,6 +93,7 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock,

*max_blocks = min(mapped_blocks, *max_blocks);
MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
+ MSDOS_I(inode)->i_disksize = MSDOS_I(inode)->mmu_private;

err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
if (err)
@@ -406,6 +407,7 @@ int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
if (error < 0)
return error;
MSDOS_I(inode)->mmu_private = inode->i_size;
+ MSDOS_I(inode)->i_disksize = inode->i_size;

set_nlink(inode, fat_subdirs(inode));
} else { /* not a directory */
@@ -421,6 +423,7 @@ int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
inode->i_fop = &fat_file_operations;
inode->i_mapping->a_ops = &fat_aops;
MSDOS_I(inode)->mmu_private = inode->i_size;
+ MSDOS_I(inode)->i_disksize = inode->i_size;
}
if (de->attr & ATTR_SYS) {
if (sbi->options.sys_immutable)
@@ -1218,6 +1221,7 @@ static int fat_read_root(struct inode *inode)
& ~((loff_t)sbi->cluster_size - 1)) >> 9;
MSDOS_I(inode)->i_logstart = 0;
MSDOS_I(inode)->mmu_private = inode->i_size;
+ MSDOS_I(inode)->i_disksize = inode->i_size;

fat_save_attrs(inode, ATTR_DIR);
inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
--
1.7.9.5


2013-10-27 13:38:47

by OGAWA Hirofumi

[permalink] [raw]
Subject: Re: [PATCH 1/5] fat: add i_disksize to represent uninitialized size

Namjae Jeon <[email protected]> writes:

Code seems to be much became simpler.

> diff --git a/fs/fat/cache.c b/fs/fat/cache.c
> index 91ad9e1..37572c2 100644
> --- a/fs/fat/cache.c
> +++ b/fs/fat/cache.c
> @@ -329,10 +329,10 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
> return 0;
>
> /*
> - * ->mmu_private can access on only allocation path.
> + * ->i_disksize can access on only allocation path.
> * (caller must hold ->i_mutex)
> */
> - last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1))
> + last_block = (MSDOS_I(inode)->i_disksize + (blocksize - 1))
> >> blocksize_bits;
> if (sector >= last_block)
> return 0;

Hm, bmap() ioctl returns between ->mmu_private and i_disksize? I'm not
checking other FSes what does...
--
OGAWA Hirofumi <[email protected]>

2013-10-29 23:01:10

by Namjae Jeon

[permalink] [raw]
Subject: Re: [PATCH 1/5] fat: add i_disksize to represent uninitialized size

2013/10/27, OGAWA Hirofumi <[email protected]>:
> Namjae Jeon <[email protected]> writes:
Hi OGAWA.
>
> Code seems to be much became simpler.
Thanks :)
>
>> diff --git a/fs/fat/cache.c b/fs/fat/cache.c
>> index 91ad9e1..37572c2 100644
>> --- a/fs/fat/cache.c
>> +++ b/fs/fat/cache.c
>> @@ -329,10 +329,10 @@ int fat_bmap(struct inode *inode, sector_t sector,
>> sector_t *phys,
>> return 0;
>>
>> /*
>> - * ->mmu_private can access on only allocation path.
>> + * ->i_disksize can access on only allocation path.
>> * (caller must hold ->i_mutex)
>> */
>> - last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1))
>> + last_block = (MSDOS_I(inode)->i_disksize + (blocksize - 1))
>> >> blocksize_bits;
>> if (sector >= last_block)
>> return 0;
>
> Hm, bmap() ioctl returns between ->mmu_private and i_disksize? I'm not
> checking other FSes what does...
I added this code after checking such behaviour from ext4.

Thanks.
> --
> OGAWA Hirofumi <[email protected]>
>

2013-10-30 01:23:41

by OGAWA Hirofumi

[permalink] [raw]
Subject: Re: [PATCH 1/5] fat: add i_disksize to represent uninitialized size

Namjae Jeon <[email protected]> writes:

>>> diff --git a/fs/fat/cache.c b/fs/fat/cache.c
>>> index 91ad9e1..37572c2 100644
>>> --- a/fs/fat/cache.c
>>> +++ b/fs/fat/cache.c
>>> @@ -329,10 +329,10 @@ int fat_bmap(struct inode *inode, sector_t sector,
>>> sector_t *phys,
>>> return 0;
>>>
>>> /*
>>> - * ->mmu_private can access on only allocation path.
>>> + * ->i_disksize can access on only allocation path.
>>> * (caller must hold ->i_mutex)
>>> */
>>> - last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1))
>>> + last_block = (MSDOS_I(inode)->i_disksize + (blocksize - 1))
>>> >> blocksize_bits;
>>> if (sector >= last_block)
>>> return 0;
>>
>> Hm, bmap() ioctl returns between ->mmu_private and i_disksize? I'm not
>> checking other FSes what does...
> I added this code after checking such behaviour from ext4.

OK. I will check with it. BTW, comment should say the both
(i.e. ->mmu_private and ->i_disksize must under ->i_mutex).
--
OGAWA Hirofumi <[email protected]>

2013-10-30 04:34:32

by Namjae Jeon

[permalink] [raw]
Subject: Re: [PATCH 1/5] fat: add i_disksize to represent uninitialized size

2013/10/30, OGAWA Hirofumi <[email protected]>:
> Namjae Jeon <[email protected]> writes:
>
>>>> diff --git a/fs/fat/cache.c b/fs/fat/cache.c
>>>> index 91ad9e1..37572c2 100644
>>>> --- a/fs/fat/cache.c
>>>> +++ b/fs/fat/cache.c
>>>> @@ -329,10 +329,10 @@ int fat_bmap(struct inode *inode, sector_t
>>>> sector,
>>>> sector_t *phys,
>>>> return 0;
>>>>
>>>> /*
>>>> - * ->mmu_private can access on only allocation path.
>>>> + * ->i_disksize can access on only allocation path.
>>>> * (caller must hold ->i_mutex)
>>>> */
>>>> - last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1))
>>>> + last_block = (MSDOS_I(inode)->i_disksize + (blocksize - 1))
>>>> >> blocksize_bits;
>>>> if (sector >= last_block)
>>>> return 0;
>>>
>>> Hm, bmap() ioctl returns between ->mmu_private and i_disksize? I'm not
>>> checking other FSes what does...
>> I added this code after checking such behaviour from ext4.
>
> OK. I will check with it. BTW, comment should say the both
> (i.e. ->mmu_private and ->i_disksize must under ->i_mutex).
Okay, I will update.
Thanks!
> --
> OGAWA Hirofumi <[email protected]>
>