2015-06-05 10:35:13

by Chao Yu

[permalink] [raw]
Subject: [PATCH] f2fs: do not trim preallocated blocks when truncating after i_size

When we perform generic/092 in xfstests, output is like below:

XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
0: [0..10239]: data
0: [0..10239]: data
-1: [10240..20479]: unwritten
+1: [10240..14335]: unwritten

This is because with this testcase, we redefine the regulation for
truncate in perallocated space past i_size as below:

"There was some confused about what the fs was supposed to do when you
truncate at i_size with preallocated space past i_size. We decided on the
following things.

1) truncate(i_size) will trim all blocks past i_size.
2) truncate(x) where x > i_size will not trim all blocks past i_size.
"

This method is used in xfs, and then ext4/btrfs will follow the rule.

This patch fixes to follow the new rule for f2fs.

Signed-off-by: Chao Yu <[email protected]>
---
fs/f2fs/file.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 4d42d66..85f97af 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -651,16 +651,16 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
f2fs_get_encryption_info(inode))
return -EACCES;

- if (attr->ia_size != i_size_read(inode)) {
+ if (attr->ia_size <= i_size_read(inode)) {
truncate_setsize(inode, attr->ia_size);
f2fs_truncate(inode);
f2fs_balance_fs(F2FS_I_SB(inode));
} else {
/*
- * giving a chance to truncate blocks past EOF which
- * are fallocated with FALLOC_FL_KEEP_SIZE.
+ * do not trim all blocks after i_size if target size is
+ * larger than i_size.
*/
- f2fs_truncate(inode);
+ truncate_setsize(inode, attr->ia_size);
}
}

--
2.4.2


2015-06-08 18:06:54

by Jaegeuk Kim

[permalink] [raw]
Subject: Re: [PATCH] f2fs: do not trim preallocated blocks when truncating after i_size

On Fri, Jun 05, 2015 at 06:34:02PM +0800, Chao Yu wrote:
> When we perform generic/092 in xfstests, output is like below:
>
> XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> 0: [0..10239]: data
> 0: [0..10239]: data
> -1: [10240..20479]: unwritten
> +1: [10240..14335]: unwritten
>
> This is because with this testcase, we redefine the regulation for
> truncate in perallocated space past i_size as below:
>
> "There was some confused about what the fs was supposed to do when you
> truncate at i_size with preallocated space past i_size. We decided on the
> following things.
>
> 1) truncate(i_size) will trim all blocks past i_size.
> 2) truncate(x) where x > i_size will not trim all blocks past i_size.
> "
>
> This method is used in xfs, and then ext4/btrfs will follow the rule.
>
> This patch fixes to follow the new rule for f2fs.
>
> Signed-off-by: Chao Yu <[email protected]>
> ---
> fs/f2fs/file.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 4d42d66..85f97af 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -651,16 +651,16 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
> f2fs_get_encryption_info(inode))
> return -EACCES;
>
> - if (attr->ia_size != i_size_read(inode)) {
> + if (attr->ia_size <= i_size_read(inode)) {
> truncate_setsize(inode, attr->ia_size);
> f2fs_truncate(inode);
> f2fs_balance_fs(F2FS_I_SB(inode));
> } else {
> /*
> - * giving a chance to truncate blocks past EOF which
> - * are fallocated with FALLOC_FL_KEEP_SIZE.
> + * do not trim all blocks after i_size if target size is
> + * larger than i_size.
> */
> - f2fs_truncate(inode);
> + truncate_setsize(inode, attr->ia_size);

So, we can do:
truncate_setsize();

if (attr->ia_size <= i_size_read(inode)) {
f2fs_truncate(inode);
f2fs_balance_fs();
}

Right?

> }
> }
>
> --
> 2.4.2

2015-06-09 02:23:56

by Chao Yu

[permalink] [raw]
Subject: RE: [PATCH] f2fs: do not trim preallocated blocks when truncating after i_size

> -----Original Message-----
> From: Jaegeuk Kim [mailto:[email protected]]
> Sent: Tuesday, June 09, 2015 2:07 AM
> To: Chao Yu
> Cc: [email protected]; [email protected]
> Subject: Re: [PATCH] f2fs: do not trim preallocated blocks when truncating after i_size
>
> On Fri, Jun 05, 2015 at 06:34:02PM +0800, Chao Yu wrote:
> > When we perform generic/092 in xfstests, output is like below:
> >
> > XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> > 0: [0..10239]: data
> > 0: [0..10239]: data
> > -1: [10240..20479]: unwritten
> > +1: [10240..14335]: unwritten
> >
> > This is because with this testcase, we redefine the regulation for
> > truncate in perallocated space past i_size as below:
> >
> > "There was some confused about what the fs was supposed to do when you
> > truncate at i_size with preallocated space past i_size. We decided on the
> > following things.
> >
> > 1) truncate(i_size) will trim all blocks past i_size.
> > 2) truncate(x) where x > i_size will not trim all blocks past i_size.
> > "
> >
> > This method is used in xfs, and then ext4/btrfs will follow the rule.
> >
> > This patch fixes to follow the new rule for f2fs.
> >
> > Signed-off-by: Chao Yu <[email protected]>
> > ---
> > fs/f2fs/file.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > index 4d42d66..85f97af 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -651,16 +651,16 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
> > f2fs_get_encryption_info(inode))
> > return -EACCES;
> >
> > - if (attr->ia_size != i_size_read(inode)) {
> > + if (attr->ia_size <= i_size_read(inode)) {
> > truncate_setsize(inode, attr->ia_size);
> > f2fs_truncate(inode);
> > f2fs_balance_fs(F2FS_I_SB(inode));
> > } else {
> > /*
> > - * giving a chance to truncate blocks past EOF which
> > - * are fallocated with FALLOC_FL_KEEP_SIZE.
> > + * do not trim all blocks after i_size if target size is
> > + * larger than i_size.
> > */
> > - f2fs_truncate(inode);
> > + truncate_setsize(inode, attr->ia_size);
>
> So, we can do:
> truncate_setsize();
>
> if (attr->ia_size <= i_size_read(inode)) {
> f2fs_truncate(inode);
> f2fs_balance_fs();
> }
>
> Right?

Yes, let me fix and resend the patch.

Thanks,
>
> > }
> > }
> >
> > --
> > 2.4.2