+++ /dev/null
-From 5c8403d27896c1124612b4db8fd0438771d5b6c3 Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Tue, 6 Jun 2023 14:08:47 +0100
-Subject: Drop the netfs_ prefix from netfs_extract_iter_to_sg()
-
-From: David Howells <dhowells@redhat.com>
-
-[ Upstream commit 0d7aeb68700ff87b4d2acafb789408a065225e1e ]
-
-Rename netfs_extract_iter_to_sg() and its auxiliary functions to drop the
-netfs_ prefix.
-
-Signed-off-by: David Howells <dhowells@redhat.com>
-cc: Jeff Layton <jlayton@kernel.org>
-cc: Steve French <sfrench@samba.org>
-cc: Shyam Prasad N <nspmangalore@gmail.com>
-cc: Rohith Surabattula <rohiths.msft@gmail.com>
-cc: Jens Axboe <axboe@kernel.dk>
-cc: Herbert Xu <herbert@gondor.apana.org.au>
-cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
-cc: "David S. Miller" <davem@davemloft.net>
-cc: Eric Dumazet <edumazet@google.com>
-cc: Jakub Kicinski <kuba@kernel.org>
-cc: Paolo Abeni <pabeni@redhat.com>
-cc: linux-crypto@vger.kernel.org
-cc: linux-cachefs@redhat.com
-cc: linux-cifs@vger.kernel.org
-cc: linux-fsdevel@vger.kernel.org
-cc: netdev@vger.kernel.org
-Signed-off-by: Paolo Abeni <pabeni@redhat.com>
-Stable-dep-of: f443fd5af5db ("crypto, cifs: fix error handling in extract_iter_to_sg()")
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- fs/netfs/iterator.c | 66 +++++++++++++++++++--------------------
- fs/smb/client/smb2ops.c | 4 +--
- fs/smb/client/smbdirect.c | 2 +-
- include/linux/netfs.h | 6 ++--
- 4 files changed, 39 insertions(+), 39 deletions(-)
-
-diff --git a/fs/netfs/iterator.c b/fs/netfs/iterator.c
-index 8a4c866874297..f8eba3de1a975 100644
---- a/fs/netfs/iterator.c
-+++ b/fs/netfs/iterator.c
-@@ -106,11 +106,11 @@ EXPORT_SYMBOL_GPL(netfs_extract_user_iter);
- * Extract and pin a list of up to sg_max pages from UBUF- or IOVEC-class
- * iterators, and add them to the scatterlist.
- */
--static ssize_t netfs_extract_user_to_sg(struct iov_iter *iter,
-- ssize_t maxsize,
-- struct sg_table *sgtable,
-- unsigned int sg_max,
-- iov_iter_extraction_t extraction_flags)
-+static ssize_t extract_user_to_sg(struct iov_iter *iter,
-+ ssize_t maxsize,
-+ struct sg_table *sgtable,
-+ unsigned int sg_max,
-+ iov_iter_extraction_t extraction_flags)
- {
- struct scatterlist *sg = sgtable->sgl + sgtable->nents;
- struct page **pages;
-@@ -159,11 +159,11 @@ static ssize_t netfs_extract_user_to_sg(struct iov_iter *iter,
- * Extract up to sg_max pages from a BVEC-type iterator and add them to the
- * scatterlist. The pages are not pinned.
- */
--static ssize_t netfs_extract_bvec_to_sg(struct iov_iter *iter,
-- ssize_t maxsize,
-- struct sg_table *sgtable,
-- unsigned int sg_max,
-- iov_iter_extraction_t extraction_flags)
-+static ssize_t extract_bvec_to_sg(struct iov_iter *iter,
-+ ssize_t maxsize,
-+ struct sg_table *sgtable,
-+ unsigned int sg_max,
-+ iov_iter_extraction_t extraction_flags)
- {
- const struct bio_vec *bv = iter->bvec;
- struct scatterlist *sg = sgtable->sgl + sgtable->nents;
-@@ -205,11 +205,11 @@ static ssize_t netfs_extract_bvec_to_sg(struct iov_iter *iter,
- * scatterlist. This can deal with vmalloc'd buffers as well as kmalloc'd or
- * static buffers. The pages are not pinned.
- */
--static ssize_t netfs_extract_kvec_to_sg(struct iov_iter *iter,
-- ssize_t maxsize,
-- struct sg_table *sgtable,
-- unsigned int sg_max,
-- iov_iter_extraction_t extraction_flags)
-+static ssize_t extract_kvec_to_sg(struct iov_iter *iter,
-+ ssize_t maxsize,
-+ struct sg_table *sgtable,
-+ unsigned int sg_max,
-+ iov_iter_extraction_t extraction_flags)
- {
- const struct kvec *kv = iter->kvec;
- struct scatterlist *sg = sgtable->sgl + sgtable->nents;
-@@ -266,11 +266,11 @@ static ssize_t netfs_extract_kvec_to_sg(struct iov_iter *iter,
- * Extract up to sg_max folios from an XARRAY-type iterator and add them to
- * the scatterlist. The pages are not pinned.
- */
--static ssize_t netfs_extract_xarray_to_sg(struct iov_iter *iter,
-- ssize_t maxsize,
-- struct sg_table *sgtable,
-- unsigned int sg_max,
-- iov_iter_extraction_t extraction_flags)
-+static ssize_t extract_xarray_to_sg(struct iov_iter *iter,
-+ ssize_t maxsize,
-+ struct sg_table *sgtable,
-+ unsigned int sg_max,
-+ iov_iter_extraction_t extraction_flags)
- {
- struct scatterlist *sg = sgtable->sgl + sgtable->nents;
- struct xarray *xa = iter->xarray;
-@@ -312,7 +312,7 @@ static ssize_t netfs_extract_xarray_to_sg(struct iov_iter *iter,
- }
-
- /**
-- * netfs_extract_iter_to_sg - Extract pages from an iterator and add ot an sglist
-+ * extract_iter_to_sg - Extract pages from an iterator and add ot an sglist
- * @iter: The iterator to extract from
- * @maxsize: The amount of iterator to copy
- * @sgtable: The scatterlist table to fill in
-@@ -339,9 +339,9 @@ static ssize_t netfs_extract_xarray_to_sg(struct iov_iter *iter,
- * The iov_iter_extract_mode() function should be used to query how cleanup
- * should be performed.
- */
--ssize_t netfs_extract_iter_to_sg(struct iov_iter *iter, size_t maxsize,
-- struct sg_table *sgtable, unsigned int sg_max,
-- iov_iter_extraction_t extraction_flags)
-+ssize_t extract_iter_to_sg(struct iov_iter *iter, size_t maxsize,
-+ struct sg_table *sgtable, unsigned int sg_max,
-+ iov_iter_extraction_t extraction_flags)
- {
- if (maxsize == 0)
- return 0;
-@@ -349,21 +349,21 @@ ssize_t netfs_extract_iter_to_sg(struct iov_iter *iter, size_t maxsize,
- switch (iov_iter_type(iter)) {
- case ITER_UBUF:
- case ITER_IOVEC:
-- return netfs_extract_user_to_sg(iter, maxsize, sgtable, sg_max,
-- extraction_flags);
-+ return extract_user_to_sg(iter, maxsize, sgtable, sg_max,
-+ extraction_flags);
- case ITER_BVEC:
-- return netfs_extract_bvec_to_sg(iter, maxsize, sgtable, sg_max,
-- extraction_flags);
-+ return extract_bvec_to_sg(iter, maxsize, sgtable, sg_max,
-+ extraction_flags);
- case ITER_KVEC:
-- return netfs_extract_kvec_to_sg(iter, maxsize, sgtable, sg_max,
-- extraction_flags);
-+ return extract_kvec_to_sg(iter, maxsize, sgtable, sg_max,
-+ extraction_flags);
- case ITER_XARRAY:
-- return netfs_extract_xarray_to_sg(iter, maxsize, sgtable, sg_max,
-- extraction_flags);
-+ return extract_xarray_to_sg(iter, maxsize, sgtable, sg_max,
-+ extraction_flags);
- default:
- pr_err("%s(%u) unsupported\n", __func__, iov_iter_type(iter));
- WARN_ON_ONCE(1);
- return -EIO;
- }
- }
--EXPORT_SYMBOL_GPL(netfs_extract_iter_to_sg);
-+EXPORT_SYMBOL_GPL(extract_iter_to_sg);
-diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
-index 3bac586e8a8eb..5dec02361b69d 100644
---- a/fs/smb/client/smb2ops.c
-+++ b/fs/smb/client/smb2ops.c
-@@ -4374,8 +4374,8 @@ static void *smb2_get_aead_req(struct crypto_aead *tfm, struct smb_rqst *rqst,
- }
- sgtable.orig_nents = sgtable.nents;
-
-- rc = netfs_extract_iter_to_sg(iter, count, &sgtable,
-- num_sgs - sgtable.nents, 0);
-+ rc = extract_iter_to_sg(iter, count, &sgtable,
-+ num_sgs - sgtable.nents, 0);
- iov_iter_revert(iter, rc);
- sgtable.orig_nents = sgtable.nents;
- }
-diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
-index 0362ebd4fa0fc..223e17c16b602 100644
---- a/fs/smb/client/smbdirect.c
-+++ b/fs/smb/client/smbdirect.c
-@@ -2227,7 +2227,7 @@ static int smbd_iter_to_mr(struct smbd_connection *info,
-
- memset(sgt->sgl, 0, max_sg * sizeof(struct scatterlist));
-
-- ret = netfs_extract_iter_to_sg(iter, iov_iter_count(iter), sgt, max_sg, 0);
-+ ret = extract_iter_to_sg(iter, iov_iter_count(iter), sgt, max_sg, 0);
- WARN_ON(ret < 0);
- if (sgt->nents > 0)
- sg_mark_end(&sgt->sgl[sgt->nents - 1]);
-diff --git a/include/linux/netfs.h b/include/linux/netfs.h
-index a1f3522daa698..55e201c3a8416 100644
---- a/include/linux/netfs.h
-+++ b/include/linux/netfs.h
-@@ -301,9 +301,9 @@ ssize_t netfs_extract_user_iter(struct iov_iter *orig, size_t orig_len,
- struct iov_iter *new,
- iov_iter_extraction_t extraction_flags);
- struct sg_table;
--ssize_t netfs_extract_iter_to_sg(struct iov_iter *iter, size_t len,
-- struct sg_table *sgtable, unsigned int sg_max,
-- iov_iter_extraction_t extraction_flags);
-+ssize_t extract_iter_to_sg(struct iov_iter *iter, size_t len,
-+ struct sg_table *sgtable, unsigned int sg_max,
-+ iov_iter_extraction_t extraction_flags);
-
- /**
- * netfs_inode - Get the netfs inode context from the inode
---
-2.40.1
-
+++ /dev/null
-From 6ed957095c5beea5dcc0534b994220930e55723d Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Tue, 6 Jun 2023 14:08:50 +0100
-Subject: Move netfs_extract_iter_to_sg() to lib/scatterlist.c
-
-From: David Howells <dhowells@redhat.com>
-
-[ Upstream commit f5f82cd18732d828bcd1ec308c4e8c55012e84b0 ]
-
-Move netfs_extract_iter_to_sg() to lib/scatterlist.c as it's going to be
-used by more than just network filesystems (AF_ALG, for example).
-
-Signed-off-by: David Howells <dhowells@redhat.com>
-cc: Jeff Layton <jlayton@kernel.org>
-cc: Steve French <sfrench@samba.org>
-cc: Shyam Prasad N <nspmangalore@gmail.com>
-cc: Rohith Surabattula <rohiths.msft@gmail.com>
-cc: Jens Axboe <axboe@kernel.dk>
-cc: Herbert Xu <herbert@gondor.apana.org.au>
-cc: "David S. Miller" <davem@davemloft.net>
-cc: Eric Dumazet <edumazet@google.com>
-cc: Jakub Kicinski <kuba@kernel.org>
-cc: Paolo Abeni <pabeni@redhat.com>
-cc: Matthew Wilcox <willy@infradead.org>
-cc: linux-crypto@vger.kernel.org
-cc: linux-cachefs@redhat.com
-cc: linux-cifs@vger.kernel.org
-cc: linux-fsdevel@vger.kernel.org
-cc: netdev@vger.kernel.org
-Signed-off-by: Paolo Abeni <pabeni@redhat.com>
-Stable-dep-of: f443fd5af5db ("crypto, cifs: fix error handling in extract_iter_to_sg()")
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- fs/netfs/iterator.c | 267 -----------------------------------------
- include/linux/netfs.h | 4 -
- include/linux/uio.h | 5 +
- lib/scatterlist.c | 269 ++++++++++++++++++++++++++++++++++++++++++
- 4 files changed, 274 insertions(+), 271 deletions(-)
-
-diff --git a/fs/netfs/iterator.c b/fs/netfs/iterator.c
-index 9f09dc30ceb65..2ff07ba655a07 100644
---- a/fs/netfs/iterator.c
-+++ b/fs/netfs/iterator.c
-@@ -101,270 +101,3 @@ ssize_t netfs_extract_user_iter(struct iov_iter *orig, size_t orig_len,
- return npages;
- }
- EXPORT_SYMBOL_GPL(netfs_extract_user_iter);
--
--/*
-- * Extract and pin a list of up to sg_max pages from UBUF- or IOVEC-class
-- * iterators, and add them to the scatterlist.
-- */
--static ssize_t extract_user_to_sg(struct iov_iter *iter,
-- ssize_t maxsize,
-- struct sg_table *sgtable,
-- unsigned int sg_max,
-- iov_iter_extraction_t extraction_flags)
--{
-- struct scatterlist *sg = sgtable->sgl + sgtable->nents;
-- struct page **pages;
-- unsigned int npages;
-- ssize_t ret = 0, res;
-- size_t len, off;
--
-- /* We decant the page list into the tail of the scatterlist */
-- pages = (void *)sgtable->sgl +
-- array_size(sg_max, sizeof(struct scatterlist));
-- pages -= sg_max;
--
-- do {
-- res = iov_iter_extract_pages(iter, &pages, maxsize, sg_max,
-- extraction_flags, &off);
-- if (res < 0)
-- goto failed;
--
-- len = res;
-- maxsize -= len;
-- ret += len;
-- npages = DIV_ROUND_UP(off + len, PAGE_SIZE);
-- sg_max -= npages;
--
-- for (; npages > 0; npages--) {
-- struct page *page = *pages;
-- size_t seg = min_t(size_t, PAGE_SIZE - off, len);
--
-- *pages++ = NULL;
-- sg_set_page(sg, page, seg, off);
-- sgtable->nents++;
-- sg++;
-- len -= seg;
-- off = 0;
-- }
-- } while (maxsize > 0 && sg_max > 0);
--
-- return ret;
--
--failed:
-- while (sgtable->nents > sgtable->orig_nents)
-- put_page(sg_page(&sgtable->sgl[--sgtable->nents]));
-- return res;
--}
--
--/*
-- * Extract up to sg_max pages from a BVEC-type iterator and add them to the
-- * scatterlist. The pages are not pinned.
-- */
--static ssize_t extract_bvec_to_sg(struct iov_iter *iter,
-- ssize_t maxsize,
-- struct sg_table *sgtable,
-- unsigned int sg_max,
-- iov_iter_extraction_t extraction_flags)
--{
-- const struct bio_vec *bv = iter->bvec;
-- struct scatterlist *sg = sgtable->sgl + sgtable->nents;
-- unsigned long start = iter->iov_offset;
-- unsigned int i;
-- ssize_t ret = 0;
--
-- for (i = 0; i < iter->nr_segs; i++) {
-- size_t off, len;
--
-- len = bv[i].bv_len;
-- if (start >= len) {
-- start -= len;
-- continue;
-- }
--
-- len = min_t(size_t, maxsize, len - start);
-- off = bv[i].bv_offset + start;
--
-- sg_set_page(sg, bv[i].bv_page, len, off);
-- sgtable->nents++;
-- sg++;
-- sg_max--;
--
-- ret += len;
-- maxsize -= len;
-- if (maxsize <= 0 || sg_max == 0)
-- break;
-- start = 0;
-- }
--
-- if (ret > 0)
-- iov_iter_advance(iter, ret);
-- return ret;
--}
--
--/*
-- * Extract up to sg_max pages from a KVEC-type iterator and add them to the
-- * scatterlist. This can deal with vmalloc'd buffers as well as kmalloc'd or
-- * static buffers. The pages are not pinned.
-- */
--static ssize_t extract_kvec_to_sg(struct iov_iter *iter,
-- ssize_t maxsize,
-- struct sg_table *sgtable,
-- unsigned int sg_max,
-- iov_iter_extraction_t extraction_flags)
--{
-- const struct kvec *kv = iter->kvec;
-- struct scatterlist *sg = sgtable->sgl + sgtable->nents;
-- unsigned long start = iter->iov_offset;
-- unsigned int i;
-- ssize_t ret = 0;
--
-- for (i = 0; i < iter->nr_segs; i++) {
-- struct page *page;
-- unsigned long kaddr;
-- size_t off, len, seg;
--
-- len = kv[i].iov_len;
-- if (start >= len) {
-- start -= len;
-- continue;
-- }
--
-- kaddr = (unsigned long)kv[i].iov_base + start;
-- off = kaddr & ~PAGE_MASK;
-- len = min_t(size_t, maxsize, len - start);
-- kaddr &= PAGE_MASK;
--
-- maxsize -= len;
-- ret += len;
-- do {
-- seg = min_t(size_t, len, PAGE_SIZE - off);
-- if (is_vmalloc_or_module_addr((void *)kaddr))
-- page = vmalloc_to_page((void *)kaddr);
-- else
-- page = virt_to_page(kaddr);
--
-- sg_set_page(sg, page, len, off);
-- sgtable->nents++;
-- sg++;
-- sg_max--;
--
-- len -= seg;
-- kaddr += PAGE_SIZE;
-- off = 0;
-- } while (len > 0 && sg_max > 0);
--
-- if (maxsize <= 0 || sg_max == 0)
-- break;
-- start = 0;
-- }
--
-- if (ret > 0)
-- iov_iter_advance(iter, ret);
-- return ret;
--}
--
--/*
-- * Extract up to sg_max folios from an XARRAY-type iterator and add them to
-- * the scatterlist. The pages are not pinned.
-- */
--static ssize_t extract_xarray_to_sg(struct iov_iter *iter,
-- ssize_t maxsize,
-- struct sg_table *sgtable,
-- unsigned int sg_max,
-- iov_iter_extraction_t extraction_flags)
--{
-- struct scatterlist *sg = sgtable->sgl + sgtable->nents;
-- struct xarray *xa = iter->xarray;
-- struct folio *folio;
-- loff_t start = iter->xarray_start + iter->iov_offset;
-- pgoff_t index = start / PAGE_SIZE;
-- ssize_t ret = 0;
-- size_t offset, len;
-- XA_STATE(xas, xa, index);
--
-- rcu_read_lock();
--
-- xas_for_each(&xas, folio, ULONG_MAX) {
-- if (xas_retry(&xas, folio))
-- continue;
-- if (WARN_ON(xa_is_value(folio)))
-- break;
-- if (WARN_ON(folio_test_hugetlb(folio)))
-- break;
--
-- offset = offset_in_folio(folio, start);
-- len = min_t(size_t, maxsize, folio_size(folio) - offset);
--
-- sg_set_page(sg, folio_page(folio, 0), len, offset);
-- sgtable->nents++;
-- sg++;
-- sg_max--;
--
-- maxsize -= len;
-- ret += len;
-- if (maxsize <= 0 || sg_max == 0)
-- break;
-- }
--
-- rcu_read_unlock();
-- if (ret > 0)
-- iov_iter_advance(iter, ret);
-- return ret;
--}
--
--/**
-- * extract_iter_to_sg - Extract pages from an iterator and add to an sglist
-- * @iter: The iterator to extract from
-- * @maxsize: The amount of iterator to copy
-- * @sgtable: The scatterlist table to fill in
-- * @sg_max: Maximum number of elements in @sgtable that may be filled
-- * @extraction_flags: Flags to qualify the request
-- *
-- * Extract the page fragments from the given amount of the source iterator and
-- * add them to a scatterlist that refers to all of those bits, to a maximum
-- * addition of @sg_max elements.
-- *
-- * The pages referred to by UBUF- and IOVEC-type iterators are extracted and
-- * pinned; BVEC-, KVEC- and XARRAY-type are extracted but aren't pinned; PIPE-
-- * and DISCARD-type are not supported.
-- *
-- * No end mark is placed on the scatterlist; that's left to the caller.
-- *
-- * @extraction_flags can have ITER_ALLOW_P2PDMA set to request peer-to-peer DMA
-- * be allowed on the pages extracted.
-- *
-- * If successful, @sgtable->nents is updated to include the number of elements
-- * added and the number of bytes added is returned. @sgtable->orig_nents is
-- * left unaltered.
-- *
-- * The iov_iter_extract_mode() function should be used to query how cleanup
-- * should be performed.
-- */
--ssize_t extract_iter_to_sg(struct iov_iter *iter, size_t maxsize,
-- struct sg_table *sgtable, unsigned int sg_max,
-- iov_iter_extraction_t extraction_flags)
--{
-- if (maxsize == 0)
-- return 0;
--
-- switch (iov_iter_type(iter)) {
-- case ITER_UBUF:
-- case ITER_IOVEC:
-- return extract_user_to_sg(iter, maxsize, sgtable, sg_max,
-- extraction_flags);
-- case ITER_BVEC:
-- return extract_bvec_to_sg(iter, maxsize, sgtable, sg_max,
-- extraction_flags);
-- case ITER_KVEC:
-- return extract_kvec_to_sg(iter, maxsize, sgtable, sg_max,
-- extraction_flags);
-- case ITER_XARRAY:
-- return extract_xarray_to_sg(iter, maxsize, sgtable, sg_max,
-- extraction_flags);
-- default:
-- pr_err("%s(%u) unsupported\n", __func__, iov_iter_type(iter));
-- WARN_ON_ONCE(1);
-- return -EIO;
-- }
--}
--EXPORT_SYMBOL_GPL(extract_iter_to_sg);
-diff --git a/include/linux/netfs.h b/include/linux/netfs.h
-index 55e201c3a8416..b11a84f6c32b7 100644
---- a/include/linux/netfs.h
-+++ b/include/linux/netfs.h
-@@ -300,10 +300,6 @@ void netfs_stats_show(struct seq_file *);
- ssize_t netfs_extract_user_iter(struct iov_iter *orig, size_t orig_len,
- struct iov_iter *new,
- iov_iter_extraction_t extraction_flags);
--struct sg_table;
--ssize_t extract_iter_to_sg(struct iov_iter *iter, size_t len,
-- struct sg_table *sgtable, unsigned int sg_max,
-- iov_iter_extraction_t extraction_flags);
-
- /**
- * netfs_inode - Get the netfs inode context from the inode
-diff --git a/include/linux/uio.h b/include/linux/uio.h
-index 044c1d8c230cf..0ccb983cf645a 100644
---- a/include/linux/uio.h
-+++ b/include/linux/uio.h
-@@ -433,4 +433,9 @@ static inline bool iov_iter_extract_will_pin(const struct iov_iter *iter)
- return user_backed_iter(iter);
- }
-
-+struct sg_table;
-+ssize_t extract_iter_to_sg(struct iov_iter *iter, size_t len,
-+ struct sg_table *sgtable, unsigned int sg_max,
-+ iov_iter_extraction_t extraction_flags);
-+
- #endif
-diff --git a/lib/scatterlist.c b/lib/scatterlist.c
-index 8d7519a8f308d..e97d7060329e8 100644
---- a/lib/scatterlist.c
-+++ b/lib/scatterlist.c
-@@ -9,6 +9,8 @@
- #include <linux/scatterlist.h>
- #include <linux/highmem.h>
- #include <linux/kmemleak.h>
-+#include <linux/bvec.h>
-+#include <linux/uio.h>
-
- /**
- * sg_next - return the next scatterlist entry in a list
-@@ -1095,3 +1097,270 @@ size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents,
- return offset;
- }
- EXPORT_SYMBOL(sg_zero_buffer);
-+
-+/*
-+ * Extract and pin a list of up to sg_max pages from UBUF- or IOVEC-class
-+ * iterators, and add them to the scatterlist.
-+ */
-+static ssize_t extract_user_to_sg(struct iov_iter *iter,
-+ ssize_t maxsize,
-+ struct sg_table *sgtable,
-+ unsigned int sg_max,
-+ iov_iter_extraction_t extraction_flags)
-+{
-+ struct scatterlist *sg = sgtable->sgl + sgtable->nents;
-+ struct page **pages;
-+ unsigned int npages;
-+ ssize_t ret = 0, res;
-+ size_t len, off;
-+
-+ /* We decant the page list into the tail of the scatterlist */
-+ pages = (void *)sgtable->sgl +
-+ array_size(sg_max, sizeof(struct scatterlist));
-+ pages -= sg_max;
-+
-+ do {
-+ res = iov_iter_extract_pages(iter, &pages, maxsize, sg_max,
-+ extraction_flags, &off);
-+ if (res < 0)
-+ goto failed;
-+
-+ len = res;
-+ maxsize -= len;
-+ ret += len;
-+ npages = DIV_ROUND_UP(off + len, PAGE_SIZE);
-+ sg_max -= npages;
-+
-+ for (; npages > 0; npages--) {
-+ struct page *page = *pages;
-+ size_t seg = min_t(size_t, PAGE_SIZE - off, len);
-+
-+ *pages++ = NULL;
-+ sg_set_page(sg, page, seg, off);
-+ sgtable->nents++;
-+ sg++;
-+ len -= seg;
-+ off = 0;
-+ }
-+ } while (maxsize > 0 && sg_max > 0);
-+
-+ return ret;
-+
-+failed:
-+ while (sgtable->nents > sgtable->orig_nents)
-+ put_page(sg_page(&sgtable->sgl[--sgtable->nents]));
-+ return res;
-+}
-+
-+/*
-+ * Extract up to sg_max pages from a BVEC-type iterator and add them to the
-+ * scatterlist. The pages are not pinned.
-+ */
-+static ssize_t extract_bvec_to_sg(struct iov_iter *iter,
-+ ssize_t maxsize,
-+ struct sg_table *sgtable,
-+ unsigned int sg_max,
-+ iov_iter_extraction_t extraction_flags)
-+{
-+ const struct bio_vec *bv = iter->bvec;
-+ struct scatterlist *sg = sgtable->sgl + sgtable->nents;
-+ unsigned long start = iter->iov_offset;
-+ unsigned int i;
-+ ssize_t ret = 0;
-+
-+ for (i = 0; i < iter->nr_segs; i++) {
-+ size_t off, len;
-+
-+ len = bv[i].bv_len;
-+ if (start >= len) {
-+ start -= len;
-+ continue;
-+ }
-+
-+ len = min_t(size_t, maxsize, len - start);
-+ off = bv[i].bv_offset + start;
-+
-+ sg_set_page(sg, bv[i].bv_page, len, off);
-+ sgtable->nents++;
-+ sg++;
-+ sg_max--;
-+
-+ ret += len;
-+ maxsize -= len;
-+ if (maxsize <= 0 || sg_max == 0)
-+ break;
-+ start = 0;
-+ }
-+
-+ if (ret > 0)
-+ iov_iter_advance(iter, ret);
-+ return ret;
-+}
-+
-+/*
-+ * Extract up to sg_max pages from a KVEC-type iterator and add them to the
-+ * scatterlist. This can deal with vmalloc'd buffers as well as kmalloc'd or
-+ * static buffers. The pages are not pinned.
-+ */
-+static ssize_t extract_kvec_to_sg(struct iov_iter *iter,
-+ ssize_t maxsize,
-+ struct sg_table *sgtable,
-+ unsigned int sg_max,
-+ iov_iter_extraction_t extraction_flags)
-+{
-+ const struct kvec *kv = iter->kvec;
-+ struct scatterlist *sg = sgtable->sgl + sgtable->nents;
-+ unsigned long start = iter->iov_offset;
-+ unsigned int i;
-+ ssize_t ret = 0;
-+
-+ for (i = 0; i < iter->nr_segs; i++) {
-+ struct page *page;
-+ unsigned long kaddr;
-+ size_t off, len, seg;
-+
-+ len = kv[i].iov_len;
-+ if (start >= len) {
-+ start -= len;
-+ continue;
-+ }
-+
-+ kaddr = (unsigned long)kv[i].iov_base + start;
-+ off = kaddr & ~PAGE_MASK;
-+ len = min_t(size_t, maxsize, len - start);
-+ kaddr &= PAGE_MASK;
-+
-+ maxsize -= len;
-+ ret += len;
-+ do {
-+ seg = min_t(size_t, len, PAGE_SIZE - off);
-+ if (is_vmalloc_or_module_addr((void *)kaddr))
-+ page = vmalloc_to_page((void *)kaddr);
-+ else
-+ page = virt_to_page(kaddr);
-+
-+ sg_set_page(sg, page, len, off);
-+ sgtable->nents++;
-+ sg++;
-+ sg_max--;
-+
-+ len -= seg;
-+ kaddr += PAGE_SIZE;
-+ off = 0;
-+ } while (len > 0 && sg_max > 0);
-+
-+ if (maxsize <= 0 || sg_max == 0)
-+ break;
-+ start = 0;
-+ }
-+
-+ if (ret > 0)
-+ iov_iter_advance(iter, ret);
-+ return ret;
-+}
-+
-+/*
-+ * Extract up to sg_max folios from an XARRAY-type iterator and add them to
-+ * the scatterlist. The pages are not pinned.
-+ */
-+static ssize_t extract_xarray_to_sg(struct iov_iter *iter,
-+ ssize_t maxsize,
-+ struct sg_table *sgtable,
-+ unsigned int sg_max,
-+ iov_iter_extraction_t extraction_flags)
-+{
-+ struct scatterlist *sg = sgtable->sgl + sgtable->nents;
-+ struct xarray *xa = iter->xarray;
-+ struct folio *folio;
-+ loff_t start = iter->xarray_start + iter->iov_offset;
-+ pgoff_t index = start / PAGE_SIZE;
-+ ssize_t ret = 0;
-+ size_t offset, len;
-+ XA_STATE(xas, xa, index);
-+
-+ rcu_read_lock();
-+
-+ xas_for_each(&xas, folio, ULONG_MAX) {
-+ if (xas_retry(&xas, folio))
-+ continue;
-+ if (WARN_ON(xa_is_value(folio)))
-+ break;
-+ if (WARN_ON(folio_test_hugetlb(folio)))
-+ break;
-+
-+ offset = offset_in_folio(folio, start);
-+ len = min_t(size_t, maxsize, folio_size(folio) - offset);
-+
-+ sg_set_page(sg, folio_page(folio, 0), len, offset);
-+ sgtable->nents++;
-+ sg++;
-+ sg_max--;
-+
-+ maxsize -= len;
-+ ret += len;
-+ if (maxsize <= 0 || sg_max == 0)
-+ break;
-+ }
-+
-+ rcu_read_unlock();
-+ if (ret > 0)
-+ iov_iter_advance(iter, ret);
-+ return ret;
-+}
-+
-+/**
-+ * extract_iter_to_sg - Extract pages from an iterator and add to an sglist
-+ * @iter: The iterator to extract from
-+ * @maxsize: The amount of iterator to copy
-+ * @sgtable: The scatterlist table to fill in
-+ * @sg_max: Maximum number of elements in @sgtable that may be filled
-+ * @extraction_flags: Flags to qualify the request
-+ *
-+ * Extract the page fragments from the given amount of the source iterator and
-+ * add them to a scatterlist that refers to all of those bits, to a maximum
-+ * addition of @sg_max elements.
-+ *
-+ * The pages referred to by UBUF- and IOVEC-type iterators are extracted and
-+ * pinned; BVEC-, KVEC- and XARRAY-type are extracted but aren't pinned; PIPE-
-+ * and DISCARD-type are not supported.
-+ *
-+ * No end mark is placed on the scatterlist; that's left to the caller.
-+ *
-+ * @extraction_flags can have ITER_ALLOW_P2PDMA set to request peer-to-peer DMA
-+ * be allowed on the pages extracted.
-+ *
-+ * If successful, @sgtable->nents is updated to include the number of elements
-+ * added and the number of bytes added is returned. @sgtable->orig_nents is
-+ * left unaltered.
-+ *
-+ * The iov_iter_extract_mode() function should be used to query how cleanup
-+ * should be performed.
-+ */
-+ssize_t extract_iter_to_sg(struct iov_iter *iter, size_t maxsize,
-+ struct sg_table *sgtable, unsigned int sg_max,
-+ iov_iter_extraction_t extraction_flags)
-+{
-+ if (maxsize == 0)
-+ return 0;
-+
-+ switch (iov_iter_type(iter)) {
-+ case ITER_UBUF:
-+ case ITER_IOVEC:
-+ return extract_user_to_sg(iter, maxsize, sgtable, sg_max,
-+ extraction_flags);
-+ case ITER_BVEC:
-+ return extract_bvec_to_sg(iter, maxsize, sgtable, sg_max,
-+ extraction_flags);
-+ case ITER_KVEC:
-+ return extract_kvec_to_sg(iter, maxsize, sgtable, sg_max,
-+ extraction_flags);
-+ case ITER_XARRAY:
-+ return extract_xarray_to_sg(iter, maxsize, sgtable, sg_max,
-+ extraction_flags);
-+ default:
-+ pr_err("%s(%u) unsupported\n", __func__, iov_iter_type(iter));
-+ WARN_ON_ONCE(1);
-+ return -EIO;
-+ }
-+}
-+EXPORT_SYMBOL_GPL(extract_iter_to_sg);
---
-2.40.1
-
projects / thirdparty / kernel / stable-queue.git / commitdiff
