| Message ID | 20181216231704.16761-1-longli@linuxonhyperv.com |
|---|---|
| State | New |
| Headers | show |
| Series | CIFS: use the correct length when pinning memory for direct I/O for write | expand |
On Sun, Dec 16, 2018 at 11:17:04PM +0000, Long Li wrote: > From: Long Li <longli@microsoft.com> > > The current code attempts to pin memory using the largest possible wsize > based on the currect SMB credits. This doesn't cause kernel oops but this is > not optimal as we may pin more pages then actually needed. > > Fix this by only pinning what are needed for doing this write I/O. > > Signed-off-by: Long Li <longli@microsoft.com> > Cc: stable@vger.kernel.org Looks sane to me. Reviewed-by: Joey Pabalinas <joeypabalinas@gmail.com> > --- > fs/cifs/file.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/cifs/file.c b/fs/cifs/file.c > index 3467351..c23bf9d 100644 > --- a/fs/cifs/file.c > +++ b/fs/cifs/file.c > @@ -2617,11 +2617,13 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, > if (rc) > break; > > + cur_len = min_t(const size_t, len, wsize); > + > if (ctx->direct_io) { > ssize_t result; > > result = iov_iter_get_pages_alloc( > - from, &pagevec, wsize, &start); > + from, &pagevec, cur_len, &start); > if (result < 0) { > cifs_dbg(VFS, > "direct_writev couldn't get user pages " > -- > 2.7.4 >
merged into cifs-2.6.git for-next On Sun, Dec 16, 2018 at 5:18 PM Long Li <longli@linuxonhyperv.com> wrote: > > From: Long Li <longli@microsoft.com> > > The current code attempts to pin memory using the largest possible wsize > based on the currect SMB credits. This doesn't cause kernel oops but this is > not optimal as we may pin more pages then actually needed. > > Fix this by only pinning what are needed for doing this write I/O. > > Signed-off-by: Long Li <longli@microsoft.com> > Cc: stable@vger.kernel.org > --- > fs/cifs/file.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/cifs/file.c b/fs/cifs/file.c > index 3467351..c23bf9d 100644 > --- a/fs/cifs/file.c > +++ b/fs/cifs/file.c > @@ -2617,11 +2617,13 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, > if (rc) > break; > > + cur_len = min_t(const size_t, len, wsize); > + > if (ctx->direct_io) { > ssize_t result; > > result = iov_iter_get_pages_alloc( > - from, &pagevec, wsize, &start); > + from, &pagevec, cur_len, &start); > if (result < 0) { > cifs_dbg(VFS, > "direct_writev couldn't get user pages " > -- > 2.7.4 >
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 3467351..c23bf9d 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2617,11 +2617,13 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, if (rc) break; + cur_len = min_t(const size_t, len, wsize); + if (ctx->direct_io) { ssize_t result; result = iov_iter_get_pages_alloc( - from, &pagevec, wsize, &start); + from, &pagevec, cur_len, &start); if (result < 0) { cifs_dbg(VFS, "direct_writev couldn't get user pages "