From: Keith Busch <kbusch@kernel.org>
No more callers.
Signed-off-by: Keith Busch <kbusch@kernel.org>
---
include/linux/uio.h | 2 -
lib/iov_iter.c | 95 ---------------------------------------------
2 files changed, 97 deletions(-)
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 2e86c653186c6..5b127043a1519 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -286,8 +286,6 @@ size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
#endif
size_t iov_iter_zero(size_t bytes, struct iov_iter *);
-bool iov_iter_is_aligned(const struct iov_iter *i, unsigned addr_mask,
- unsigned len_mask);
unsigned long iov_iter_alignment(const struct iov_iter *i);
unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov,
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index f9193f952f499..2fe66a6b8789e 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -784,101 +784,6 @@ void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count)
}
EXPORT_SYMBOL(iov_iter_discard);
-static bool iov_iter_aligned_iovec(const struct iov_iter *i, unsigned addr_mask,
- unsigned len_mask)
-{
- const struct iovec *iov = iter_iov(i);
- size_t size = i->count;
- size_t skip = i->iov_offset;
-
- do {
- size_t len = iov->iov_len - skip;
-
- if (len > size)
- len = size;
- if (len & len_mask)
- return false;
- if ((unsigned long)(iov->iov_base + skip) & addr_mask)
- return false;
-
- iov++;
- size -= len;
- skip = 0;
- } while (size);
-
- return true;
-}
-
-static bool iov_iter_aligned_bvec(const struct iov_iter *i, unsigned addr_mask,
- unsigned len_mask)
-{
- const struct bio_vec *bvec = i->bvec;
- unsigned skip = i->iov_offset;
- size_t size = i->count;
-
- do {
- size_t len = bvec->bv_len - skip;
-
- if (len > size)
- len = size;
- if (len & len_mask)
- return false;
- if ((unsigned long)(bvec->bv_offset + skip) & addr_mask)
- return false;
-
- bvec++;
- size -= len;
- skip = 0;
- } while (size);
-
- return true;
-}
-
-/**
- * iov_iter_is_aligned() - Check if the addresses and lengths of each segments
- * are aligned to the parameters.
- *
- * @i: &struct iov_iter to restore
- * @addr_mask: bit mask to check against the iov element's addresses
- * @len_mask: bit mask to check against the iov element's lengths
- *
- * Return: false if any addresses or lengths intersect with the provided masks
- */
-bool iov_iter_is_aligned(const struct iov_iter *i, unsigned addr_mask,
- unsigned len_mask)
-{
- if (likely(iter_is_ubuf(i))) {
- if (i->count & len_mask)
- return false;
- if ((unsigned long)(i->ubuf + i->iov_offset) & addr_mask)
- return false;
- return true;
- }
-
- if (likely(iter_is_iovec(i) || iov_iter_is_kvec(i)))
- return iov_iter_aligned_iovec(i, addr_mask, len_mask);
-
- if (iov_iter_is_bvec(i))
- return iov_iter_aligned_bvec(i, addr_mask, len_mask);
-
- /* With both xarray and folioq types, we're dealing with whole folios. */
- if (iov_iter_is_xarray(i)) {
- if (i->count & len_mask)
- return false;
- if ((i->xarray_start + i->iov_offset) & addr_mask)
- return false;
- }
- if (iov_iter_is_folioq(i)) {
- if (i->count & len_mask)
- return false;
- if (i->iov_offset & addr_mask)
- return false;
- }
-
- return true;
-}
-EXPORT_SYMBOL_GPL(iov_iter_is_aligned);
-
static unsigned long iov_iter_alignment_iovec(const struct iov_iter *i)
{
const struct iovec *iov = iter_iov(i);
--
2.47.3On Fri, Aug 01, 2025 at 04:47:36PM -0700, Keith Busch wrote:
> From: Keith Busch <kbusch@kernel.org>
>
> No more callers.
>
> Signed-off-by: Keith Busch <kbusch@kernel.org>
You had me up until this last patch.
I'm actually making use of iov_iter_is_aligned() in a series of
changes for both NFS and NFSD. Chuck has included some of the
NFSD changes in his nfsd-testing branch, see:
https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/commit/?h=nfsd-testing&id=5d78ac1e674b45f9c9e3769b48efb27c44f4e4d3
And the balance of my work that is pending review/inclusion is:
https://lore.kernel.org/linux-nfs/20250731230633.89983-1-snitzer@kernel.org/
https://lore.kernel.org/linux-nfs/20250801171049.94235-1-snitzer@kernel.org/
I only need iov_iter_aligned_bvec, but recall I want to relax its
checking with this patch:
https://lore.kernel.org/linux-nfs/20250708160619.64800-5-snitzer@kernel.org/
Should I just add iov_iter_aligned_bvec() to fs/nfs_common/ so that
both NFS and NFSD can use it?
Thanks,
Mike
> ---
> include/linux/uio.h | 2 -
> lib/iov_iter.c | 95 ---------------------------------------------
> 2 files changed, 97 deletions(-)
>
> diff --git a/include/linux/uio.h b/include/linux/uio.h
> index 2e86c653186c6..5b127043a1519 100644
> --- a/include/linux/uio.h
> +++ b/include/linux/uio.h
> @@ -286,8 +286,6 @@ size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
> #endif
>
> size_t iov_iter_zero(size_t bytes, struct iov_iter *);
> -bool iov_iter_is_aligned(const struct iov_iter *i, unsigned addr_mask,
> - unsigned len_mask);
> unsigned long iov_iter_alignment(const struct iov_iter *i);
> unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
> void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov,
> diff --git a/lib/iov_iter.c b/lib/iov_iter.c
> index f9193f952f499..2fe66a6b8789e 100644
> --- a/lib/iov_iter.c
> +++ b/lib/iov_iter.c
> @@ -784,101 +784,6 @@ void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count)
> }
> EXPORT_SYMBOL(iov_iter_discard);
>
> -static bool iov_iter_aligned_iovec(const struct iov_iter *i, unsigned addr_mask,
> - unsigned len_mask)
> -{
> - const struct iovec *iov = iter_iov(i);
> - size_t size = i->count;
> - size_t skip = i->iov_offset;
> -
> - do {
> - size_t len = iov->iov_len - skip;
> -
> - if (len > size)
> - len = size;
> - if (len & len_mask)
> - return false;
> - if ((unsigned long)(iov->iov_base + skip) & addr_mask)
> - return false;
> -
> - iov++;
> - size -= len;
> - skip = 0;
> - } while (size);
> -
> - return true;
> -}
> -
> -static bool iov_iter_aligned_bvec(const struct iov_iter *i, unsigned addr_mask,
> - unsigned len_mask)
> -{
> - const struct bio_vec *bvec = i->bvec;
> - unsigned skip = i->iov_offset;
> - size_t size = i->count;
> -
> - do {
> - size_t len = bvec->bv_len - skip;
> -
> - if (len > size)
> - len = size;
> - if (len & len_mask)
> - return false;
> - if ((unsigned long)(bvec->bv_offset + skip) & addr_mask)
> - return false;
> -
> - bvec++;
> - size -= len;
> - skip = 0;
> - } while (size);
> -
> - return true;
> -}
> -
> -/**
> - * iov_iter_is_aligned() - Check if the addresses and lengths of each segments
> - * are aligned to the parameters.
> - *
> - * @i: &struct iov_iter to restore
> - * @addr_mask: bit mask to check against the iov element's addresses
> - * @len_mask: bit mask to check against the iov element's lengths
> - *
> - * Return: false if any addresses or lengths intersect with the provided masks
> - */
> -bool iov_iter_is_aligned(const struct iov_iter *i, unsigned addr_mask,
> - unsigned len_mask)
> -{
> - if (likely(iter_is_ubuf(i))) {
> - if (i->count & len_mask)
> - return false;
> - if ((unsigned long)(i->ubuf + i->iov_offset) & addr_mask)
> - return false;
> - return true;
> - }
> -
> - if (likely(iter_is_iovec(i) || iov_iter_is_kvec(i)))
> - return iov_iter_aligned_iovec(i, addr_mask, len_mask);
> -
> - if (iov_iter_is_bvec(i))
> - return iov_iter_aligned_bvec(i, addr_mask, len_mask);
> -
> - /* With both xarray and folioq types, we're dealing with whole folios. */
> - if (iov_iter_is_xarray(i)) {
> - if (i->count & len_mask)
> - return false;
> - if ((i->xarray_start + i->iov_offset) & addr_mask)
> - return false;
> - }
> - if (iov_iter_is_folioq(i)) {
> - if (i->count & len_mask)
> - return false;
> - if (i->iov_offset & addr_mask)
> - return false;
> - }
> -
> - return true;
> -}
> -EXPORT_SYMBOL_GPL(iov_iter_is_aligned);
> -
> static unsigned long iov_iter_alignment_iovec(const struct iov_iter *i)
> {
> const struct iovec *iov = iter_iov(i);
> --
> 2.47.3
>
On Fri, Aug 01, 2025 at 10:02:49PM -0400, Mike Snitzer wrote: > On Fri, Aug 01, 2025 at 04:47:36PM -0700, Keith Busch wrote: > > From: Keith Busch <kbusch@kernel.org> > > > > No more callers. > > > > Signed-off-by: Keith Busch <kbusch@kernel.org> > > You had me up until this last patch. > > I'm actually making use of iov_iter_is_aligned() in a series of > changes for both NFS and NFSD. Chuck has included some of the > NFSD changes in his nfsd-testing branch, see: > https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/commit/?h=nfsd-testing&id=5d78ac1e674b45f9c9e3769b48efb27c44f4e4d3 > > And the balance of my work that is pending review/inclusion is: > https://lore.kernel.org/linux-nfs/20250731230633.89983-1-snitzer@kernel.org/ > https://lore.kernel.org/linux-nfs/20250801171049.94235-1-snitzer@kernel.org/ > > I only need iov_iter_aligned_bvec, but recall I want to relax its > checking with this patch: > https://lore.kernel.org/linux-nfs/20250708160619.64800-5-snitzer@kernel.org/ > > Should I just add iov_iter_aligned_bvec() to fs/nfs_common/ so that > both NFS and NFSD can use it? If at all possible, I recommend finding a place that already walks the vectors and do an opprotunistic check for the alignments there. This will save CPU cycles. For example, nfsd_iter_read already iterates the bvec while setting each page. Could you check the alignment while doing that instead of iterating a second time immediately after?
On Mon, Aug 04, 2025 at 08:16:39AM -0600, Keith Busch wrote: > On Fri, Aug 01, 2025 at 10:02:49PM -0400, Mike Snitzer wrote: > > On Fri, Aug 01, 2025 at 04:47:36PM -0700, Keith Busch wrote: > > > From: Keith Busch <kbusch@kernel.org> > > > > > > No more callers. > > > > > > Signed-off-by: Keith Busch <kbusch@kernel.org> > > > > You had me up until this last patch. > > > > I'm actually making use of iov_iter_is_aligned() in a series of > > changes for both NFS and NFSD. Chuck has included some of the > > NFSD changes in his nfsd-testing branch, see: > > https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/commit/?h=nfsd-testing&id=5d78ac1e674b45f9c9e3769b48efb27c44f4e4d3 > > > > And the balance of my work that is pending review/inclusion is: > > https://lore.kernel.org/linux-nfs/20250731230633.89983-1-snitzer@kernel.org/ > > https://lore.kernel.org/linux-nfs/20250801171049.94235-1-snitzer@kernel.org/ > > > > I only need iov_iter_aligned_bvec, but recall I want to relax its > > checking with this patch: > > https://lore.kernel.org/linux-nfs/20250708160619.64800-5-snitzer@kernel.org/ > > > > Should I just add iov_iter_aligned_bvec() to fs/nfs_common/ so that > > both NFS and NFSD can use it? > > If at all possible, I recommend finding a place that already walks the > vectors and do an opprotunistic check for the alignments there. This > will save CPU cycles. For example, nfsd_iter_read already iterates the > bvec while setting each page. Could you check the alignment while doing > that instead of iterating a second time immediately after? Nice goal, I'll see if I can pull it off. I'm currently using iov_iter_is_aligned() in 3 new call sites (for READ and WRITE) in both NFS and NFSD: nfs_local_iter_init, nfsd_iter_read, nfsd_vfs_write nfsd_vfs_write is the only one that doesn't iterate the bvec as-is, but it does work that _should_ obviate the need to doable check the alignment.
On Mon, Aug 04, 2025 at 11:25:08AM -0400, Mike Snitzer wrote: > On Mon, Aug 04, 2025 at 08:16:39AM -0600, Keith Busch wrote: > > On Fri, Aug 01, 2025 at 10:02:49PM -0400, Mike Snitzer wrote: > > > On Fri, Aug 01, 2025 at 04:47:36PM -0700, Keith Busch wrote: > > > > From: Keith Busch <kbusch@kernel.org> > > > > > > > > No more callers. > > > > > > > > Signed-off-by: Keith Busch <kbusch@kernel.org> > > > > > > You had me up until this last patch. > > > > > > I'm actually making use of iov_iter_is_aligned() in a series of > > > changes for both NFS and NFSD. Chuck has included some of the > > > NFSD changes in his nfsd-testing branch, see: > > > https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/commit/?h=nfsd-testing&id=5d78ac1e674b45f9c9e3769b48efb27c44f4e4d3 > > > > > > And the balance of my work that is pending review/inclusion is: > > > https://lore.kernel.org/linux-nfs/20250731230633.89983-1-snitzer@kernel.org/ > > > https://lore.kernel.org/linux-nfs/20250801171049.94235-1-snitzer@kernel.org/ > > > > > > I only need iov_iter_aligned_bvec, but recall I want to relax its > > > checking with this patch: > > > https://lore.kernel.org/linux-nfs/20250708160619.64800-5-snitzer@kernel.org/ > > > > > > Should I just add iov_iter_aligned_bvec() to fs/nfs_common/ so that > > > both NFS and NFSD can use it? > > > > If at all possible, I recommend finding a place that already walks the > > vectors and do an opprotunistic check for the alignments there. This > > will save CPU cycles. For example, nfsd_iter_read already iterates the > > bvec while setting each page. Could you check the alignment while doing > > that instead of iterating a second time immediately after? > > Nice goal, I'll see if I can pull it off. > > I'm currently using iov_iter_is_aligned() in 3 new call sites (for > READ and WRITE) in both NFS and NFSD: nfs_local_iter_init, > nfsd_iter_read, nfsd_vfs_write > > nfsd_vfs_write is the only one that doesn't iterate the bvec as-is, > but it does work that _should_ obviate the need to doable check the > alignment. Freudian typo: s/doable/double/ :)
On Mon, Aug 04, 2025 at 11:25:08AM -0400, Mike Snitzer wrote: > On Mon, Aug 04, 2025 at 08:16:39AM -0600, Keith Busch wrote: > > On Fri, Aug 01, 2025 at 10:02:49PM -0400, Mike Snitzer wrote: > > > On Fri, Aug 01, 2025 at 04:47:36PM -0700, Keith Busch wrote: > > > > From: Keith Busch <kbusch@kernel.org> > > > > > > > > No more callers. > > > > > > > > Signed-off-by: Keith Busch <kbusch@kernel.org> > > > > > > You had me up until this last patch. > > > > > > I'm actually making use of iov_iter_is_aligned() in a series of > > > changes for both NFS and NFSD. Chuck has included some of the > > > NFSD changes in his nfsd-testing branch, see: > > > https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/commit/?h=nfsd-testing&id=5d78ac1e674b45f9c9e3769b48efb27c44f4e4d3 > > > > > > And the balance of my work that is pending review/inclusion is: > > > https://lore.kernel.org/linux-nfs/20250731230633.89983-1-snitzer@kernel.org/ > > > https://lore.kernel.org/linux-nfs/20250801171049.94235-1-snitzer@kernel.org/ > > > > > > I only need iov_iter_aligned_bvec, but recall I want to relax its > > > checking with this patch: > > > https://lore.kernel.org/linux-nfs/20250708160619.64800-5-snitzer@kernel.org/ > > > > > > Should I just add iov_iter_aligned_bvec() to fs/nfs_common/ so that > > > both NFS and NFSD can use it? > > > > If at all possible, I recommend finding a place that already walks the > > vectors and do an opprotunistic check for the alignments there. This > > will save CPU cycles. For example, nfsd_iter_read already iterates the > > bvec while setting each page. Could you check the alignment while doing > > that instead of iterating a second time immediately after? > > Nice goal, I'll see if I can pull it off. > > I'm currently using iov_iter_is_aligned() in 3 new call sites (for > READ and WRITE) in both NFS and NFSD: nfs_local_iter_init, > nfsd_iter_read, nfsd_vfs_write > > nfsd_vfs_write is the only one that doesn't iterate the bvec as-is, > but it does work that _should_ obviate the need to doable check the > alignment. FYI, I was able to avoid using iov_iter_is_aligned() in favor of checks in earlier code (in both NFSD and NFS). Thanks, Mike
On Mon, Aug 04, 2025 at 06:26:55PM -0400, Mike Snitzer wrote: > FYI, I was able to avoid using iov_iter_is_aligned() in favor of > checks in earlier code (in both NFSD and NFS). Excellent! I promise removing the extra iteration is totally worth it. ;) I just know of one error case bug mentioned in patch 2, so unless I hear anything else, I'll spin out the new version with a fix for just that tomorrow.
On Fri, Aug 01, 2025 at 04:47:36PM -0700, Keith Busch wrote: > From: Keith Busch <kbusch@kernel.org> > > No more callers. > > Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Mike Snitzer <snitzer@kernel.org>
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