* [PATCH 6.12 634/666] netfs: fix error handling in netfs_extract_user_iter() [not found] <20260520162111.222830634@linuxfoundation.org> @ 2026-05-20 16:24 ` Greg Kroah-Hartman 2026-05-22 20:23 ` Harshit Mogalapalli 0 siblings, 1 reply; 3+ messages in thread From: Greg Kroah-Hartman @ 2026-05-20 16:24 UTC (permalink / raw) To: stable Cc: Greg Kroah-Hartman, patches, Xiaoli Feng, Paulo Alcantara (Red Hat), David Howells, netfs, linux-cifs, linux-fsdevel, Christian Brauner 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paulo Alcantara <pc@manguebit.org> commit 0aad5704c6b4d14007d4eab15883e8524e4310f4 upstream. In netfs_extract_user_iter(), if iov_iter_extract_pages() failed to extract user pages, bail out on -ENOMEM, otherwise return the error code only if @npages == 0, allowing short DIO reads and writes to be issued. This fixes mmapstress02 from LTP tests against CIFS. Fixes: 85dd2c8ff368 ("netfs: Add a function to extract a UBUF or IOVEC into a BVEC iterator") Reported-by: Xiaoli Feng <xifeng@redhat.com> Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-10-dhowells@redhat.com Cc: netfs@lists.linux.dev Cc: stable@vger.kernel.org Cc: linux-cifs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- fs/netfs/iterator.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) --- a/fs/netfs/iterator.c +++ b/fs/netfs/iterator.c @@ -22,7 +22,7 @@ * * Extract the page fragments from the given amount of the source iterator and * build up a second iterator that refers to all of those bits. This allows - * the original iterator to disposed of. + * the original iterator to be disposed of. * * @extraction_flags can have ITER_ALLOW_P2PDMA set to request peer-to-peer DMA be * allowed on the pages extracted. @@ -67,8 +67,8 @@ ssize_t netfs_extract_user_iter(struct i ret = iov_iter_extract_pages(orig, &pages, count, max_pages - npages, extraction_flags, &offset); - if (ret < 0) { - pr_err("Couldn't get user pages (rc=%zd)\n", ret); + if (unlikely(ret <= 0)) { + ret = ret ?: -EIO; break; } @@ -97,6 +97,13 @@ ssize_t netfs_extract_user_iter(struct i npages += cur_npages; } + if (ret < 0 && (ret == -ENOMEM || npages == 0)) { + for (i = 0; i < npages; i++) + unpin_user_page(bv[i].bv_page); + kvfree(bv); + return ret; + } + iov_iter_bvec(new, orig->data_source, bv, npages, orig_len - count); return npages; } ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 6.12 634/666] netfs: fix error handling in netfs_extract_user_iter() 2026-05-20 16:24 ` [PATCH 6.12 634/666] netfs: fix error handling in netfs_extract_user_iter() Greg Kroah-Hartman @ 2026-05-22 20:23 ` Harshit Mogalapalli 2026-05-23 9:22 ` Greg Kroah-Hartman 0 siblings, 1 reply; 3+ messages in thread From: Harshit Mogalapalli @ 2026-05-22 20:23 UTC (permalink / raw) To: Greg Kroah-Hartman, stable Cc: patches, Xiaoli Feng, Paulo Alcantara (Red Hat), David Howells, netfs, linux-cifs, linux-fsdevel, Christian Brauner Hi Greg/Sasha, On 20/05/26 21:54, Greg Kroah-Hartman wrote: > 6.12-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Paulo Alcantara <pc@manguebit.org> > > commit 0aad5704c6b4d14007d4eab15883e8524e4310f4 upstream. > > In netfs_extract_user_iter(), if iov_iter_extract_pages() failed to > extract user pages, bail out on -ENOMEM, otherwise return the error > code only if @npages == 0, allowing short DIO reads and writes to be > issued. > > This fixes mmapstress02 from LTP tests against CIFS. > > Fixes: 85dd2c8ff368 ("netfs: Add a function to extract a UBUF or IOVEC into a BVEC iterator") > Reported-by: Xiaoli Feng <xifeng@redhat.com> > Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> > Signed-off-by: David Howells <dhowells@redhat.com> > Link: https://patch.msgid.link/20260512123404.719402-10-dhowells@redhat.com > Cc: netfs@lists.linux.dev > Cc: stable@vger.kernel.org > Cc: linux-cifs@vger.kernel.org > Cc: linux-fsdevel@vger.kernel.org > Signed-off-by: Christian Brauner <brauner@kernel.org> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > --- > fs/netfs/iterator.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > --- a/fs/netfs/iterator.c > +++ b/fs/netfs/iterator.c > @@ -22,7 +22,7 @@ > * > * Extract the page fragments from the given amount of the source iterator and > * build up a second iterator that refers to all of those bits. This allows > - * the original iterator to disposed of. > + * the original iterator to be disposed of. > * > * @extraction_flags can have ITER_ALLOW_P2PDMA set to request peer-to-peer DMA be > * allowed on the pages extracted. > @@ -67,8 +67,8 @@ ssize_t netfs_extract_user_iter(struct i > ret = iov_iter_extract_pages(orig, &pages, count, > max_pages - npages, extraction_flags, > &offset); > - if (ret < 0) { > - pr_err("Couldn't get user pages (rc=%zd)\n", ret); > + if (unlikely(ret <= 0)) { > + ret = ret ?: -EIO; > break; > } > > @@ -97,6 +97,13 @@ ssize_t netfs_extract_user_iter(struct i > npages += cur_npages; > } > > + if (ret < 0 && (ret == -ENOMEM || npages == 0)) { > + for (i = 0; i < npages; i++) > + unpin_user_page(bv[i].bv_page); > + kvfree(bv); > + return ret; > + } > + I have run an AI assisted backport review and it spotted an issue: I have taken a look and the issues goes like: Upstream has: ssize_t ret = 0; ... if (ret < 0 && (ret == -ENOMEM || npages == 0)) { for (i = 0; i < npages; i++) unpin_user_page(bv[i].bv_page); kvfree(bv); return ret; } 6.12.y has: ssize_t ret; ... if (ret < 0 && (ret == -ENOMEM || npages == 0)) { for (i = 0; i < npages; i++) unpin_user_page(bv[i].bv_page); kvfree(bv); return ret; } I think 6.12.y misses commit: 7e3d8db899d5 ("netfs: Fix potential uninitialised var in netfs_extract_user_iter()") so backport might not be complete, thoughts ? thanks, Harshit > iov_iter_bvec(new, orig->data_source, bv, npages, orig_len - count); > return npages; > } > > > ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 6.12 634/666] netfs: fix error handling in netfs_extract_user_iter() 2026-05-22 20:23 ` Harshit Mogalapalli @ 2026-05-23 9:22 ` Greg Kroah-Hartman 0 siblings, 0 replies; 3+ messages in thread From: Greg Kroah-Hartman @ 2026-05-23 9:22 UTC (permalink / raw) To: Harshit Mogalapalli Cc: stable, patches, Xiaoli Feng, Paulo Alcantara (Red Hat), David Howells, netfs, linux-cifs, linux-fsdevel, Christian Brauner On Sat, May 23, 2026 at 01:53:15AM +0530, Harshit Mogalapalli wrote: > Hi Greg/Sasha, > > On 20/05/26 21:54, Greg Kroah-Hartman wrote: > > 6.12-stable review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Paulo Alcantara <pc@manguebit.org> > > > > commit 0aad5704c6b4d14007d4eab15883e8524e4310f4 upstream. > > > > In netfs_extract_user_iter(), if iov_iter_extract_pages() failed to > > extract user pages, bail out on -ENOMEM, otherwise return the error > > code only if @npages == 0, allowing short DIO reads and writes to be > > issued. > > > > This fixes mmapstress02 from LTP tests against CIFS. > > > > Fixes: 85dd2c8ff368 ("netfs: Add a function to extract a UBUF or IOVEC into a BVEC iterator") > > Reported-by: Xiaoli Feng <xifeng@redhat.com> > > Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> > > Signed-off-by: David Howells <dhowells@redhat.com> > > Link: https://patch.msgid.link/20260512123404.719402-10-dhowells@redhat.com > > Cc: netfs@lists.linux.dev > > Cc: stable@vger.kernel.org > > Cc: linux-cifs@vger.kernel.org > > Cc: linux-fsdevel@vger.kernel.org > > Signed-off-by: Christian Brauner <brauner@kernel.org> > > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > --- > > fs/netfs/iterator.c | 13 ++++++++++--- > > 1 file changed, 10 insertions(+), 3 deletions(-) > > > > --- a/fs/netfs/iterator.c > > +++ b/fs/netfs/iterator.c > > @@ -22,7 +22,7 @@ > > * > > * Extract the page fragments from the given amount of the source iterator and > > * build up a second iterator that refers to all of those bits. This allows > > - * the original iterator to disposed of. > > + * the original iterator to be disposed of. > > * > > * @extraction_flags can have ITER_ALLOW_P2PDMA set to request peer-to-peer DMA be > > * allowed on the pages extracted. > > @@ -67,8 +67,8 @@ ssize_t netfs_extract_user_iter(struct i > > ret = iov_iter_extract_pages(orig, &pages, count, > > max_pages - npages, extraction_flags, > > &offset); > > - if (ret < 0) { > > - pr_err("Couldn't get user pages (rc=%zd)\n", ret); > > + if (unlikely(ret <= 0)) { > > + ret = ret ?: -EIO; > > break; > > } > > @@ -97,6 +97,13 @@ ssize_t netfs_extract_user_iter(struct i > > npages += cur_npages; > > } > > + if (ret < 0 && (ret == -ENOMEM || npages == 0)) { > > + for (i = 0; i < npages; i++) > > + unpin_user_page(bv[i].bv_page); > > + kvfree(bv); > > + return ret; > > + } > > + > > I have run an AI assisted backport review and it spotted an issue: I > have taken a look and the issues goes like: > > Upstream has: > > > > ssize_t ret = 0; > > ... > if (ret < 0 && (ret == -ENOMEM || npages == 0)) { > for (i = 0; i < npages; i++) > unpin_user_page(bv[i].bv_page); > kvfree(bv); > return ret; > } > > 6.12.y has: > > ssize_t ret; > > ... > if (ret < 0 && (ret == -ENOMEM || npages == 0)) { > for (i = 0; i < npages; i++) > unpin_user_page(bv[i].bv_page); > kvfree(bv); > return ret; > } > > I think 6.12.y misses commit: 7e3d8db899d5 ("netfs: Fix potential > uninitialised var in netfs_extract_user_iter()") so backport might not be > complete, thoughts ? Now applied, thanks. greg k-h ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-05-23 9:22 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <20260520162111.222830634@linuxfoundation.org>
2026-05-20 16:24 ` [PATCH 6.12 634/666] netfs: fix error handling in netfs_extract_user_iter() Greg Kroah-Hartman
2026-05-22 20:23 ` Harshit Mogalapalli
2026-05-23 9:22 ` Greg Kroah-Hartman
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox