* [PATCH] ovl: fix incorrect extent info in metacopy case
@ 2020-06-24 10:20 Chengguang Xu
2020-06-24 12:53 ` Amir Goldstein
2020-08-14 9:23 ` cgxu
0 siblings, 2 replies; 6+ messages in thread
From: Chengguang Xu @ 2020-06-24 10:20 UTC (permalink / raw)
To: miklos; +Cc: linux-unionfs, Chengguang Xu
In metacopy case, we should use ovl_inode_realdata() instead of
ovl_inode_real() to get real inode which has data, so that
we can get correct information of extentes in ->fiemap operation.
Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
---
fs/overlayfs/inode.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 981f11ec51bc..a524af04b71d 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -472,7 +472,7 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
u64 start, u64 len)
{
int err;
- struct inode *realinode = ovl_inode_real(inode);
+ struct inode *realinode = ovl_inode_realdata(inode);
const struct cred *old_cred;
if (!realinode->i_op->fiemap)
--
2.20.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] ovl: fix incorrect extent info in metacopy case
2020-06-24 10:20 [PATCH] ovl: fix incorrect extent info in metacopy case Chengguang Xu
@ 2020-06-24 12:53 ` Amir Goldstein
2020-06-25 8:35 ` Amir Goldstein
2020-08-14 9:23 ` cgxu
1 sibling, 1 reply; 6+ messages in thread
From: Amir Goldstein @ 2020-06-24 12:53 UTC (permalink / raw)
To: Chengguang Xu; +Cc: Miklos Szeredi, overlayfs
On Wed, Jun 24, 2020 at 1:23 PM Chengguang Xu <cgxu519@mykernel.net> wrote:
>
> In metacopy case, we should use ovl_inode_realdata() instead of
> ovl_inode_real() to get real inode which has data, so that
> we can get correct information of extentes in ->fiemap operation.
>
> Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
looks right
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
> ---
> fs/overlayfs/inode.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
> index 981f11ec51bc..a524af04b71d 100644
> --- a/fs/overlayfs/inode.c
> +++ b/fs/overlayfs/inode.c
> @@ -472,7 +472,7 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> u64 start, u64 len)
> {
> int err;
> - struct inode *realinode = ovl_inode_real(inode);
> + struct inode *realinode = ovl_inode_realdata(inode);
> const struct cred *old_cred;
>
> if (!realinode->i_op->fiemap)
> --
> 2.20.1
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ovl: fix incorrect extent info in metacopy case
2020-06-24 12:53 ` Amir Goldstein
@ 2020-06-25 8:35 ` Amir Goldstein
2020-06-25 9:46 ` cgxu
0 siblings, 1 reply; 6+ messages in thread
From: Amir Goldstein @ 2020-06-25 8:35 UTC (permalink / raw)
To: Chengguang Xu, Miklos Szeredi; +Cc: overlayfs
On Wed, Jun 24, 2020 at 3:53 PM Amir Goldstein <amir73il@gmail.com> wrote:
>
> On Wed, Jun 24, 2020 at 1:23 PM Chengguang Xu <cgxu519@mykernel.net> wrote:
> >
> > In metacopy case, we should use ovl_inode_realdata() instead of
> > ovl_inode_real() to get real inode which has data, so that
> > we can get correct information of extentes in ->fiemap operation.
> >
> > Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
>
> looks right
Miklos,
Not related to this patch, I noticed something that could be odd with
ovl_fiemap().
When passed the flag FIEMAP_FLAG_SYNC, ->fiemap() will trigger writeback
of lower inode pages.
This behavior is border line for overlayfs.
I did not check if filemap_write_and_wait() ends up being a noop on read-only
fs or if it can return an error.
Following ovl_fsync() practice, we may want to silently drop the
FIEMAP_FLAG_SYNC flag? but that could result in unexpected results.
Am I overthinking this?
Thanks,
Amir.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ovl: fix incorrect extent info in metacopy case
2020-06-25 8:35 ` Amir Goldstein
@ 2020-06-25 9:46 ` cgxu
0 siblings, 0 replies; 6+ messages in thread
From: cgxu @ 2020-06-25 9:46 UTC (permalink / raw)
To: Amir Goldstein, Miklos Szeredi; +Cc: overlayfs
On 6/25/20 4:35 PM, Amir Goldstein wrote:
> On Wed, Jun 24, 2020 at 3:53 PM Amir Goldstein <amir73il@gmail.com> wrote:
>> On Wed, Jun 24, 2020 at 1:23 PM Chengguang Xu <cgxu519@mykernel.net> wrote:
>>> In metacopy case, we should use ovl_inode_realdata() instead of
>>> ovl_inode_real() to get real inode which has data, so that
>>> we can get correct information of extentes in ->fiemap operation.
>>>
>>> Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
>> looks right
> Miklos,
>
> Not related to this patch, I noticed something that could be odd with
> ovl_fiemap().
>
> When passed the flag FIEMAP_FLAG_SYNC, ->fiemap() will trigger writeback
> of lower inode pages.
>
> This behavior is border line for overlayfs.
> I did not check if filemap_write_and_wait() ends up being a noop on read-only
> fs or if it can return an error.
vfs ioctl does the same behavior regardless of read-only fs and IIUC,
writeback functions will do DIRTY tag check before actually sync dirty data.
Thanks,
cgxu
> Following ovl_fsync() practice, we may want to silently drop the
> FIEMAP_FLAG_SYNC flag? but that could result in unexpected results.
>
> Am I overthinking this?
>
> Thanks,
> Amir.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ovl: fix incorrect extent info in metacopy case
2020-06-24 10:20 [PATCH] ovl: fix incorrect extent info in metacopy case Chengguang Xu
2020-06-24 12:53 ` Amir Goldstein
@ 2020-08-14 9:23 ` cgxu
2020-10-30 10:16 ` Miklos Szeredi
1 sibling, 1 reply; 6+ messages in thread
From: cgxu @ 2020-08-14 9:23 UTC (permalink / raw)
To: miklos; +Cc: linux-unionfs
On 6/24/20 6:20 PM, Chengguang Xu wrote:
> In metacopy case, we should use ovl_inode_realdata() instead of
> ovl_inode_real() to get real inode which has data, so that
> we can get correct information of extentes in ->fiemap operation.
>
> Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
ping
> ---
> fs/overlayfs/inode.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
> index 981f11ec51bc..a524af04b71d 100644
> --- a/fs/overlayfs/inode.c
> +++ b/fs/overlayfs/inode.c
> @@ -472,7 +472,7 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> u64 start, u64 len)
> {
> int err;
> - struct inode *realinode = ovl_inode_real(inode);
> + struct inode *realinode = ovl_inode_realdata(inode);
> const struct cred *old_cred;
>
> if (!realinode->i_op->fiemap)
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ovl: fix incorrect extent info in metacopy case
2020-08-14 9:23 ` cgxu
@ 2020-10-30 10:16 ` Miklos Szeredi
0 siblings, 0 replies; 6+ messages in thread
From: Miklos Szeredi @ 2020-10-30 10:16 UTC (permalink / raw)
To: cgxu; +Cc: overlayfs
On Fri, Aug 14, 2020 at 11:23 AM cgxu <cgxu519@mykernel.net> wrote:
>
> On 6/24/20 6:20 PM, Chengguang Xu wrote:
> > In metacopy case, we should use ovl_inode_realdata() instead of
> > ovl_inode_real() to get real inode which has data, so that
> > we can get correct information of extentes in ->fiemap operation.
> >
> > Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
>
> ping
Sorry, I missed this patch. Applied now.
Thanks,
Miklos
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-10-30 10:17 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2020-06-24 10:20 [PATCH] ovl: fix incorrect extent info in metacopy case Chengguang Xu
2020-06-24 12:53 ` Amir Goldstein
2020-06-25 8:35 ` Amir Goldstein
2020-06-25 9:46 ` cgxu
2020-08-14 9:23 ` cgxu
2020-10-30 10:16 ` Miklos Szeredi
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