linux-cifs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] cifs: fix fallocate when trying to allocate a hole.
@ 2021-07-23  1:21 Ronnie Sahlberg
  2021-07-23  2:25 ` Steve French
  0 siblings, 1 reply; 2+ messages in thread
From: Ronnie Sahlberg @ 2021-07-23  1:21 UTC (permalink / raw)
  To: linux-cifs; +Cc: Steve French

Remove the conditional checking for out_data_len and skipping the fallocate
if it is 0. This is wrong will actually change any legitimate the fallocate
where the entire region is unallocated into a no-op.

Additionally, before allocating the range, if FALLOC_FL_KEEP_SIZE is set then
we need to clamp the length of the fallocate region as to not extend the size of the file.

Fixes: 966a3cb7c7db ("cifs: improve fallocate emulation")
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
 fs/cifs/smb2ops.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 5cefb5972396..238717654e46 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3667,11 +3667,6 @@ static int smb3_simple_fallocate_range(unsigned int xid,
 			(char **)&out_data, &out_data_len);
 	if (rc)
 		goto out;
-	/*
-	 * It is already all allocated
-	 */
-	if (out_data_len == 0)
-		goto out;
 
 	buf = kzalloc(1024 * 1024, GFP_KERNEL);
 	if (buf == NULL) {
@@ -3794,6 +3789,24 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon,
 		goto out;
 	}
 
+	if (keep_size == true) {
+		/*
+		 * We can not preallocate pages beyond the end of the file
+		 * in SMB2.
+		 */
+		if (off >= i_size_read(inode)) {
+			rc = -EFBIG;
+			goto out;
+		}
+		/*
+		 * For fallocates that are partially beyond the end of file,
+		 * clamp len so we only fallocate up to the end of file.
+		 */
+		if (off + len > i_size_read(inode)) {
+			len = i_size_read(inode) - off;
+		}
+	}
+
 	if ((keep_size == true) || (i_size_read(inode) >= off + len)) {
 		/*
 		 * At this point, we are trying to fallocate an internal
-- 
2.30.2


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] cifs: fix fallocate when trying to allocate a hole.
  2021-07-23  1:21 [PATCH] cifs: fix fallocate when trying to allocate a hole Ronnie Sahlberg
@ 2021-07-23  2:25 ` Steve French
  0 siblings, 0 replies; 2+ messages in thread
From: Steve French @ 2021-07-23  2:25 UTC (permalink / raw)
  To: Ronnie Sahlberg; +Cc: linux-cifs

With the minor fix to change the rc from EFBIG to 0 to address the
xfstest 071 failure, tentatively merged into cifs-2.6.git for-next
pending more testing

On Thu, Jul 22, 2021 at 8:21 PM Ronnie Sahlberg <lsahlber@redhat.com> wrote:
>
> Remove the conditional checking for out_data_len and skipping the fallocate
> if it is 0. This is wrong will actually change any legitimate the fallocate
> where the entire region is unallocated into a no-op.
>
> Additionally, before allocating the range, if FALLOC_FL_KEEP_SIZE is set then
> we need to clamp the length of the fallocate region as to not extend the size of the file.
>
> Fixes: 966a3cb7c7db ("cifs: improve fallocate emulation")
> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
> ---
>  fs/cifs/smb2ops.c | 23 ++++++++++++++++++-----
>  1 file changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index 5cefb5972396..238717654e46 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -3667,11 +3667,6 @@ static int smb3_simple_fallocate_range(unsigned int xid,
>                         (char **)&out_data, &out_data_len);
>         if (rc)
>                 goto out;
> -       /*
> -        * It is already all allocated
> -        */
> -       if (out_data_len == 0)
> -               goto out;
>
>         buf = kzalloc(1024 * 1024, GFP_KERNEL);
>         if (buf == NULL) {
> @@ -3794,6 +3789,24 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon,
>                 goto out;
>         }
>
> +       if (keep_size == true) {
> +               /*
> +                * We can not preallocate pages beyond the end of the file
> +                * in SMB2.
> +                */
> +               if (off >= i_size_read(inode)) {
> +                       rc = -EFBIG;
> +                       goto out;
> +               }
> +               /*
> +                * For fallocates that are partially beyond the end of file,
> +                * clamp len so we only fallocate up to the end of file.
> +                */
> +               if (off + len > i_size_read(inode)) {
> +                       len = i_size_read(inode) - off;
> +               }
> +       }
> +
>         if ((keep_size == true) || (i_size_read(inode) >= off + len)) {
>                 /*
>                  * At this point, we are trying to fallocate an internal
> --
> 2.30.2
>


-- 
Thanks,

Steve

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2021-07-23  2:26 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-23  1:21 [PATCH] cifs: fix fallocate when trying to allocate a hole Ronnie Sahlberg
2021-07-23  2:25 ` Steve French

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).