* [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 related [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
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2021-07-23 2:25 ` Steve French
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