Re: [PATCH 14/17] cifs: Change the I/O paths to use an iterator rather than a page list

From: Steve French
Date: Fri Feb 17 2023 - 00:49:23 EST

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This had various checkpatch warnings - some are probably worth
cleaning up. Do you want to spin a v2 of this patch?

0014-cifs-Change-the-I-O-paths-to-use-an-iterator-rather-.patch
---------------------------------------------------------------
WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP
#465: FILE: fs/cifs/file.c:2444:
+ rc = -ENOTSUPP;

WARNING: Consider removing the code enclosed by this #if 0 and its #endif
#627: FILE: fs/cifs/file.c:2609:
+#if 0 // TODO: Remove for iov_iter support

WARNING: Missing a blank line after declarations
#657: FILE: fs/cifs/file.c:2937:
+ XA_STATE(xas, &mapping->i_pages, index);
+ folio_batch_init(&batch);

WARNING: Consider removing the code enclosed by this #if 0 and its #endif
#1040: FILE: fs/cifs/file.c:3512:
+#if 0 // TODO: Remove for iov_iter support

WARNING: Consider removing the code enclosed by this #if 0 and its #endif
#1067: FILE: fs/cifs/file.c:3587:
+#if 0 // TODO: Remove for iov_iter support

WARNING: Consider removing the code enclosed by this #if 0 and its #endif
#1530: FILE: fs/cifs/file.c:4217:
+#if 0 // TODO: Remove for iov_iter support

WARNING: Consider removing the code enclosed by this #if 0 and its #endif
#1837: FILE: fs/cifs/file.c:4903:
+#if 0 // TODO: Remove for iov_iter support

WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
#2190: FILE: fs/cifs/misc.c:975:
+ unsigned i;

WARNING: nested (un)?likely() calls, IS_ERR already uses unlikely() internally
#2453: FILE: fs/cifs/smb2ops.c:4409:
+ if (unlikely(IS_ERR(creq)))

total: 0 errors, 9 warnings, 3271 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
mechanically convert to the typical style using --fix or --fix-inplace.

0014-cifs-Change-the-I-O-paths-to-use-an-iterator-rather-.patch has
style problems, please review.

On Thu, Feb 16, 2023 at 3:48 PM David Howells <dhowells@xxxxxxxxxx> wrote:
>
> Currently, the cifs I/O paths hand lists of pages from the VM interface
> routines at the top all the way through the intervening layers to the
> socket interface at the bottom.
>
> This is a problem, however, for interfacing with netfslib which passes an
> iterator through to the ->issue_read() method (and will pass an iterator
> through to the ->issue_write() method in future). Netfslib takes over
> bounce buffering for direct I/O, async I/O and encrypted content, so cifs
> doesn't need to do that. Netfslib also converts IOVEC-type iterators into
> BVEC-type iterators if necessary.
>
> Further, cifs needs foliating - and folios may come in a variety of sizes,
> so a page list pointing to an array of heterogeneous pages may cause
> problems in places such as where crypto is done.
>
> Change the cifs I/O paths to hand iov_iter iterators all the way through
> instead.
>
> Notes:
>
> (1) Some old routines are #if'd out to be removed in a follow up patch so
> as to avoid confusing diff, thereby making the diff output easier to
> follow. I've removed functions that don't overlap with anything
> added.
>
> (2) struct smb_rqst loses rq_pages, rq_offset, rq_npages, rq_pagesz and
> rq_tailsz which describe the pages forming the buffer; instead there's
> an rq_iter describing the source buffer and an rq_buffer which is used
> to hold the buffer for encryption.
>
> (3) struct cifs_readdata and cifs_writedata are similarly modified to
> smb_rqst. The ->read_into_pages() and ->copy_into_pages() are then
> replaced with passing the iterator directly to the socket.
>
> The iterators are stored in these structs so that they are persistent
> and don't get deallocated when the function returns (unlike if they
> were stack variables).
>
> (4) Buffered writeback is overhauled, borrowing the code from the afs
> filesystem to gather up contiguous runs of folios. The XARRAY-type
> iterator is then used to refer directly to the pagecache and can be
> passed to the socket to transmit data directly from there.
>
> This includes:
>
> cifs_extend_writeback()
> cifs_write_back_from_locked_folio()
> cifs_writepages_region()
> cifs_writepages()
>
> (5) Pages are converted to folios.
>
> (6) Direct I/O uses netfs_extract_user_iter() to create a BVEC-type
> iterator from an IOBUF/UBUF-type source iterator.
>
> (7) smb2_get_aead_req() uses netfs_extract_iter_to_sg() to extract page
> fragments from the iterator into the scatterlists that the crypto
> layer prefers.
>
> (8) smb2_init_transform_rq() attached pages to smb_rqst::rq_buffer, an
> xarray, to use as a bounce buffer for encryption. An XARRAY-type
> iterator can then be used to pass the bounce buffer to lower layers.
>
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
> cc: Steve French <sfrench@xxxxxxxxx>
> cc: Shyam Prasad N <nspmangalore@xxxxxxxxx>
> cc: Rohith Surabattula <rohiths.msft@xxxxxxxxx>
> cc: Paulo Alcantara <pc@xxxxxx>
> cc: Jeff Layton <jlayton@xxxxxxxxxx>
> cc: linux-cifs@xxxxxxxxxxxxxxx
>
> Link: https://lore.kernel.org/r/164311907995.2806745.400147335497304099.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # rfc
> Link: https://lore.kernel.org/r/164928620163.457102.11602306234438271112.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # v1
> Link: https://lore.kernel.org/r/165211420279.3154751.15923591172438186144.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # v1
> Link: https://lore.kernel.org/r/165348880385.2106726.3220789453472800240.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # v1
> Link: https://lore.kernel.org/r/165364827111.3334034.934805882842932881.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # v3
> Link: https://lore.kernel.org/r/166126396180.708021.271013668175370826.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # v1
> Link: https://lore.kernel.org/r/166697259595.61150.5982032408321852414.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # rfc
> Link: https://lore.kernel.org/r/166732031756.3186319.12528413619888902872.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # rfc
> ---
> fs/cifs/Kconfig | 1 +
> fs/cifs/cifsencrypt.c | 28 +-
> fs/cifs/cifsglob.h | 66 +--
> fs/cifs/cifsproto.h | 8 +-
> fs/cifs/cifssmb.c | 15 +-
> fs/cifs/file.c | 1197 ++++++++++++++++++++++++++---------------
> fs/cifs/fscache.c | 22 +-
> fs/cifs/fscache.h | 10 +-
> fs/cifs/misc.c | 128 +----
> fs/cifs/smb2ops.c | 362 ++++++-------
> fs/cifs/smb2pdu.c | 53 +-
> fs/cifs/smbdirect.c | 262 ++++-----
> fs/cifs/smbdirect.h | 4 +-
> fs/cifs/transport.c | 54 +-
> 14 files changed, 1122 insertions(+), 1088 deletions(-)
>
> diff --git a/fs/cifs/Kconfig b/fs/cifs/Kconfig
> index bbf63a9eb927..4c0d53bf931a 100644
> --- a/fs/cifs/Kconfig
> +++ b/fs/cifs/Kconfig
> @@ -18,6 +18,7 @@ config CIFS
> select DNS_RESOLVER
> select ASN1
> select OID_REGISTRY
> + select NETFS_SUPPORT
> help
> This is the client VFS module for the SMB3 family of network file
> protocols (including the most recent, most secure dialect SMB3.1.1).
> diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
> index 7be589aeb520..357bd27a7fd1 100644
> --- a/fs/cifs/cifsencrypt.c
> +++ b/fs/cifs/cifsencrypt.c
> @@ -169,11 +169,11 @@ static int cifs_shash_iter(const struct iov_iter *iter, size_t maxsize,
> }
>
> int __cifs_calc_signature(struct smb_rqst *rqst,
> - struct TCP_Server_Info *server, char *signature,
> - struct shash_desc *shash)
> + struct TCP_Server_Info *server, char *signature,
> + struct shash_desc *shash)
> {
> int i;
> - int rc;
> + ssize_t rc;
> struct kvec *iov = rqst->rq_iov;
> int n_vec = rqst->rq_nvec;
>
> @@ -205,25 +205,9 @@ int __cifs_calc_signature(struct smb_rqst *rqst,
> }
> }
>
> - /* now hash over the rq_pages array */
> - for (i = 0; i < rqst->rq_npages; i++) {
> - void *kaddr;
> - unsigned int len, offset;
> -
> - rqst_page_get_length(rqst, i, &len, &offset);
> -
> - kaddr = (char *) kmap(rqst->rq_pages[i]) + offset;
> -
> - rc = crypto_shash_update(shash, kaddr, len);
> - if (rc) {
> - cifs_dbg(VFS, "%s: Could not update with payload\n",
> - __func__);
> - kunmap(rqst->rq_pages[i]);
> - return rc;
> - }
> -
> - kunmap(rqst->rq_pages[i]);
> - }
> + rc = cifs_shash_iter(&rqst->rq_iter, iov_iter_count(&rqst->rq_iter), shash);
> + if (rc < 0)
> + return rc;
>
> rc = crypto_shash_final(shash, signature);
> if (rc)
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index 1d893bea4723..893c2e21eb8e 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -216,11 +216,9 @@ static inline void cifs_free_open_info(struct cifs_open_info_data *data)
> struct smb_rqst {
> struct kvec *rq_iov; /* array of kvecs */
> unsigned int rq_nvec; /* number of kvecs in array */
> - struct page **rq_pages; /* pointer to array of page ptrs */
> - unsigned int rq_offset; /* the offset to the 1st page */
> - unsigned int rq_npages; /* number pages in array */
> - unsigned int rq_pagesz; /* page size to use */
> - unsigned int rq_tailsz; /* length of last page */
> + size_t rq_iter_size; /* Amount of data in ->rq_iter */
> + struct iov_iter rq_iter; /* Data iterator */
> + struct xarray rq_buffer; /* Page buffer for encryption */
> };
>
> struct mid_q_entry;
> @@ -1428,10 +1426,11 @@ struct cifs_aio_ctx {
> struct cifsFileInfo *cfile;
> struct bio_vec *bv;
> loff_t pos;
> - unsigned int npages;
> + unsigned int nr_pinned_pages;
> ssize_t rc;
> unsigned int len;
> unsigned int total_len;
> + unsigned int bv_need_unpin; /* If ->bv[] needs unpinning */
> bool should_dirty;
> /*
> * Indicates if this aio_ctx is for direct_io,
> @@ -1449,28 +1448,18 @@ struct cifs_readdata {
> struct address_space *mapping;
> struct cifs_aio_ctx *ctx;
> __u64 offset;
> + ssize_t got_bytes;
> unsigned int bytes;
> - unsigned int got_bytes;
> pid_t pid;
> int result;
> struct work_struct work;
> - int (*read_into_pages)(struct TCP_Server_Info *server,
> - struct cifs_readdata *rdata,
> - unsigned int len);
> - int (*copy_into_pages)(struct TCP_Server_Info *server,
> - struct cifs_readdata *rdata,
> - struct iov_iter *iter);
> + struct iov_iter iter;
> struct kvec iov[2];
> struct TCP_Server_Info *server;
> #ifdef CONFIG_CIFS_SMB_DIRECT
> struct smbd_mr *mr;
> #endif
> - unsigned int pagesz;
> - unsigned int page_offset;
> - unsigned int tailsz;
> struct cifs_credits credits;
> - unsigned int nr_pages;
> - struct page **pages;
> };
>
> /* asynchronous write support */
> @@ -1482,6 +1471,8 @@ struct cifs_writedata {
> struct work_struct work;
> struct cifsFileInfo *cfile;
> struct cifs_aio_ctx *ctx;
> + struct iov_iter iter;
> + struct bio_vec *bv;
> __u64 offset;
> pid_t pid;
> unsigned int bytes;
> @@ -1490,12 +1481,7 @@ struct cifs_writedata {
> #ifdef CONFIG_CIFS_SMB_DIRECT
> struct smbd_mr *mr;
> #endif
> - unsigned int pagesz;
> - unsigned int page_offset;
> - unsigned int tailsz;
> struct cifs_credits credits;
> - unsigned int nr_pages;
> - struct page **pages;
> };
>
> /*
> @@ -2155,9 +2141,9 @@ static inline void move_cifs_info_to_smb2(struct smb2_file_all_info *dst, const
> dst->FileNameLength = src->FileNameLength;
> }
>
> -static inline unsigned int cifs_get_num_sgs(const struct smb_rqst *rqst,
> - int num_rqst,
> - const u8 *sig)
> +static inline int cifs_get_num_sgs(const struct smb_rqst *rqst,
> + int num_rqst,
> + const u8 *sig)
> {
> unsigned int len, skip;
> unsigned int nents = 0;
> @@ -2177,6 +2163,19 @@ static inline unsigned int cifs_get_num_sgs(const struct smb_rqst *rqst,
> * rqst[1+].rq_iov[0+] data to be encrypted/decrypted
> */
> for (i = 0; i < num_rqst; i++) {
> + /* We really don't want a mixture of pinned and unpinned pages
> + * in the sglist. It's hard to keep track of which is what.
> + * Instead, we convert to a BVEC-type iterator higher up.
> + */
> + if (WARN_ON_ONCE(user_backed_iter(&rqst[i].rq_iter)))
> + return -EIO;
> +
> + /* We also don't want to have any extra refs or pins to clean
> + * up in the sglist.
> + */
> + if (WARN_ON_ONCE(iov_iter_extract_will_pin(&rqst[i].rq_iter)))
> + return -EIO;
> +
> for (j = 0; j < rqst[i].rq_nvec; j++) {
> struct kvec *iov = &rqst[i].rq_iov[j];
>
> @@ -2190,7 +2189,7 @@ static inline unsigned int cifs_get_num_sgs(const struct smb_rqst *rqst,
> }
> skip = 0;
> }
> - nents += rqst[i].rq_npages;
> + nents += iov_iter_npages(&rqst[i].rq_iter, INT_MAX);
> }
> nents += DIV_ROUND_UP(offset_in_page(sig) + SMB2_SIGNATURE_SIZE, PAGE_SIZE);
> return nents;
> @@ -2199,9 +2198,9 @@ static inline unsigned int cifs_get_num_sgs(const struct smb_rqst *rqst,
> /* We can not use the normal sg_set_buf() as we will sometimes pass a
> * stack object as buf.
> */
> -static inline struct scatterlist *cifs_sg_set_buf(struct scatterlist *sg,
> - const void *buf,
> - unsigned int buflen)
> +static inline void cifs_sg_set_buf(struct sg_table *sgtable,
> + const void *buf,
> + unsigned int buflen)
> {
> unsigned long addr = (unsigned long)buf;
> unsigned int off = offset_in_page(addr);
> @@ -2211,16 +2210,17 @@ static inline struct scatterlist *cifs_sg_set_buf(struct scatterlist *sg,
> do {
> unsigned int len = min_t(unsigned int, buflen, PAGE_SIZE - off);
>
> - sg_set_page(sg++, vmalloc_to_page((void *)addr), len, off);
> + sg_set_page(&sgtable->sgl[sgtable->nents++],
> + vmalloc_to_page((void *)addr), len, off);
>
> off = 0;
> addr += PAGE_SIZE;
> buflen -= len;
> } while (buflen);
> } else {
> - sg_set_page(sg++, virt_to_page(addr), buflen, off);
> + sg_set_page(&sgtable->sgl[sgtable->nents++],
> + virt_to_page(addr), buflen, off);
> }
> - return sg;
> }
>
> #endif /* _CIFS_GLOB_H */
> diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
> index cb7a3fe89278..2873f68a051c 100644
> --- a/fs/cifs/cifsproto.h
> +++ b/fs/cifs/cifsproto.h
> @@ -584,10 +584,7 @@ int cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid);
> int cifs_async_writev(struct cifs_writedata *wdata,
> void (*release)(struct kref *kref));
> void cifs_writev_complete(struct work_struct *work);
> -struct cifs_writedata *cifs_writedata_alloc(unsigned int nr_pages,
> - work_func_t complete);
> -struct cifs_writedata *cifs_writedata_direct_alloc(struct page **pages,
> - work_func_t complete);
> +struct cifs_writedata *cifs_writedata_alloc(work_func_t complete);
> void cifs_writedata_release(struct kref *refcount);
> int cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
> struct cifs_sb_info *cifs_sb,
> @@ -604,13 +601,10 @@ enum securityEnum cifs_select_sectype(struct TCP_Server_Info *,
> enum securityEnum);
> struct cifs_aio_ctx *cifs_aio_ctx_alloc(void);
> void cifs_aio_ctx_release(struct kref *refcount);
> -int setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw);
>
> int cifs_alloc_hash(const char *name, struct shash_desc **sdesc);
> void cifs_free_hash(struct shash_desc **sdesc);
>
> -void rqst_page_get_length(const struct smb_rqst *rqst, unsigned int page,
> - unsigned int *len, unsigned int *offset);
> struct cifs_chan *
> cifs_ses_find_chan(struct cifs_ses *ses, struct TCP_Server_Info *server);
> int cifs_try_adding_channels(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses);
> diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
> index 8c014a3ff9e0..730ae3273698 100644
> --- a/fs/cifs/cifssmb.c
> +++ b/fs/cifs/cifssmb.c
> @@ -24,6 +24,7 @@
> #include <linux/task_io_accounting_ops.h>
> #include <linux/uaccess.h>
> #include "cifspdu.h"
> +#include "cifsfs.h"
> #include "cifsglob.h"
> #include "cifsacl.h"
> #include "cifsproto.h"
> @@ -1294,11 +1295,8 @@ cifs_readv_callback(struct mid_q_entry *mid)
> struct TCP_Server_Info *server = tcon->ses->server;
> struct smb_rqst rqst = { .rq_iov = rdata->iov,
> .rq_nvec = 2,
> - .rq_pages = rdata->pages,
> - .rq_offset = rdata->page_offset,
> - .rq_npages = rdata->nr_pages,
> - .rq_pagesz = rdata->pagesz,
> - .rq_tailsz = rdata->tailsz };
> + .rq_iter_size = iov_iter_count(&rdata->iter),
> + .rq_iter = rdata->iter };
> struct cifs_credits credits = { .value = 1, .instance = 0 };
>
> cifs_dbg(FYI, "%s: mid=%llu state=%d result=%d bytes=%u\n",
> @@ -1737,11 +1735,8 @@ cifs_async_writev(struct cifs_writedata *wdata,
>
> rqst.rq_iov = iov;
> rqst.rq_nvec = 2;
> - rqst.rq_pages = wdata->pages;
> - rqst.rq_offset = wdata->page_offset;
> - rqst.rq_npages = wdata->nr_pages;
> - rqst.rq_pagesz = wdata->pagesz;
> - rqst.rq_tailsz = wdata->tailsz;
> + rqst.rq_iter = wdata->iter;
> + rqst.rq_iter_size = iov_iter_count(&wdata->iter);
>
> cifs_dbg(FYI, "async write at %llu %u bytes\n",
> wdata->offset, wdata->bytes);
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index 09240b8b018a..33779d184692 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -36,6 +36,32 @@
> #include "cifs_ioctl.h"
> #include "cached_dir.h"
>
> +/*
> + * Remove the dirty flags from a span of pages.
> + */
> +static void cifs_undirty_folios(struct inode *inode, loff_t start, unsigned int len)
> +{
> + struct address_space *mapping = inode->i_mapping;
> + struct folio *folio;
> + pgoff_t end;
> +
> + XA_STATE(xas, &mapping->i_pages, start / PAGE_SIZE);
> +
> + rcu_read_lock();
> +
> + end = (start + len - 1) / PAGE_SIZE;
> + xas_for_each_marked(&xas, folio, end, PAGECACHE_TAG_DIRTY) {
> + xas_pause(&xas);
> + rcu_read_unlock();
> + folio_lock(folio);
> + folio_clear_dirty_for_io(folio);
> + folio_unlock(folio);
> + rcu_read_lock();
> + }
> +
> + rcu_read_unlock();
> +}
> +
> /*
> * Completion of write to server.
> */
> @@ -2391,7 +2417,6 @@ cifs_writedata_release(struct kref *refcount)
> if (wdata->cfile)
> cifsFileInfo_put(wdata->cfile);
>
> - kvfree(wdata->pages);
> kfree(wdata);
> }
>
> @@ -2402,51 +2427,49 @@ cifs_writedata_release(struct kref *refcount)
> static void
> cifs_writev_requeue(struct cifs_writedata *wdata)
> {
> - int i, rc = 0;
> + int rc = 0;
> struct inode *inode = d_inode(wdata->cfile->dentry);
> struct TCP_Server_Info *server;
> - unsigned int rest_len;
> + unsigned int rest_len = wdata->bytes;
> + loff_t fpos = wdata->offset;
>
> server = tlink_tcon(wdata->cfile->tlink)->ses->server;
> - i = 0;
> - rest_len = wdata->bytes;
> do {
> struct cifs_writedata *wdata2;
> - unsigned int j, nr_pages, wsize, tailsz, cur_len;
> + unsigned int wsize, cur_len;
>
> wsize = server->ops->wp_retry_size(inode);
> if (wsize < rest_len) {
> - nr_pages = wsize / PAGE_SIZE;
> - if (!nr_pages) {
> - rc = -EOPNOTSUPP;
> + if (wsize < PAGE_SIZE) {
> + rc = -ENOTSUPP;
> break;
> }
> - cur_len = nr_pages * PAGE_SIZE;
> - tailsz = PAGE_SIZE;
> + cur_len = min(round_down(wsize, PAGE_SIZE), rest_len);
> } else {
> - nr_pages = DIV_ROUND_UP(rest_len, PAGE_SIZE);
> cur_len = rest_len;
> - tailsz = rest_len - (nr_pages - 1) * PAGE_SIZE;
> }
>
> - wdata2 = cifs_writedata_alloc(nr_pages, cifs_writev_complete);
> + wdata2 = cifs_writedata_alloc(cifs_writev_complete);
> if (!wdata2) {
> rc = -ENOMEM;
> break;
> }
>
> - for (j = 0; j < nr_pages; j++) {
> - wdata2->pages[j] = wdata->pages[i + j];
> - lock_page(wdata2->pages[j]);
> - clear_page_dirty_for_io(wdata2->pages[j]);
> - }
> -
> wdata2->sync_mode = wdata->sync_mode;
> - wdata2->nr_pages = nr_pages;
> - wdata2->offset = page_offset(wdata2->pages[0]);
> - wdata2->pagesz = PAGE_SIZE;
> - wdata2->tailsz = tailsz;
> - wdata2->bytes = cur_len;
> + wdata2->offset = fpos;
> + wdata2->bytes = cur_len;
> + wdata2->iter = wdata->iter;
> +
> + iov_iter_advance(&wdata2->iter, fpos - wdata->offset);
> + iov_iter_truncate(&wdata2->iter, wdata2->bytes);
> +
> + if (iov_iter_is_xarray(&wdata2->iter))
> + /* Check for pages having been redirtied and clean
> + * them. We can do this by walking the xarray. If
> + * it's not an xarray, then it's a DIO and we shouldn't
> + * be mucking around with the page bits.
> + */
> + cifs_undirty_folios(inode, fpos, cur_len);
>
> rc = cifs_get_writable_file(CIFS_I(inode), FIND_WR_ANY,
> &wdata2->cfile);
> @@ -2461,33 +2484,22 @@ cifs_writev_requeue(struct cifs_writedata *wdata)
> cifs_writedata_release);
> }
>
> - for (j = 0; j < nr_pages; j++) {
> - unlock_page(wdata2->pages[j]);
> - if (rc != 0 && !is_retryable_error(rc)) {
> - SetPageError(wdata2->pages[j]);
> - end_page_writeback(wdata2->pages[j]);
> - put_page(wdata2->pages[j]);
> - }
> - }
> -
> kref_put(&wdata2->refcount, cifs_writedata_release);
> if (rc) {
> if (is_retryable_error(rc))
> continue;
> - i += nr_pages;
> + fpos += cur_len;
> + rest_len -= cur_len;
> break;
> }
>
> + fpos += cur_len;
> rest_len -= cur_len;
> - i += nr_pages;
> - } while (i < wdata->nr_pages);
> + } while (rest_len > 0);
>
> - /* cleanup remaining pages from the original wdata */
> - for (; i < wdata->nr_pages; i++) {
> - SetPageError(wdata->pages[i]);
> - end_page_writeback(wdata->pages[i]);
> - put_page(wdata->pages[i]);
> - }
> + /* Clean up remaining pages from the original wdata */
> + if (iov_iter_is_xarray(&wdata->iter))
> + cifs_pages_write_failed(inode, fpos, rest_len);
>
> if (rc != 0 && !is_retryable_error(rc))
> mapping_set_error(inode->i_mapping, rc);
> @@ -2500,7 +2512,6 @@ cifs_writev_complete(struct work_struct *work)
> struct cifs_writedata *wdata = container_of(work,
> struct cifs_writedata, work);
> struct inode *inode = d_inode(wdata->cfile->dentry);
> - int i = 0;
>
> if (wdata->result == 0) {
> spin_lock(&inode->i_lock);
> @@ -2511,45 +2522,24 @@ cifs_writev_complete(struct work_struct *work)
> } else if (wdata->sync_mode == WB_SYNC_ALL && wdata->result == -EAGAIN)
> return cifs_writev_requeue(wdata);
>
> - for (i = 0; i < wdata->nr_pages; i++) {
> - struct page *page = wdata->pages[i];
> + if (wdata->result == -EAGAIN)
> + cifs_pages_write_redirty(inode, wdata->offset, wdata->bytes);
> + else if (wdata->result < 0)
> + cifs_pages_write_failed(inode, wdata->offset, wdata->bytes);
> + else
> + cifs_pages_written_back(inode, wdata->offset, wdata->bytes);
>
> - if (wdata->result == -EAGAIN)
> - __set_page_dirty_nobuffers(page);
> - else if (wdata->result < 0)
> - SetPageError(page);
> - end_page_writeback(page);
> - cifs_readpage_to_fscache(inode, page);
> - put_page(page);
> - }
> if (wdata->result != -EAGAIN)
> mapping_set_error(inode->i_mapping, wdata->result);
> kref_put(&wdata->refcount, cifs_writedata_release);
> }
>
> -struct cifs_writedata *
> -cifs_writedata_alloc(unsigned int nr_pages, work_func_t complete)
> -{
> - struct cifs_writedata *writedata = NULL;
> - struct page **pages =
> - kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
> - if (pages) {
> - writedata = cifs_writedata_direct_alloc(pages, complete);
> - if (!writedata)
> - kvfree(pages);
> - }
> -
> - return writedata;
> -}
> -
> -struct cifs_writedata *
> -cifs_writedata_direct_alloc(struct page **pages, work_func_t complete)
> +struct cifs_writedata *cifs_writedata_alloc(work_func_t complete)
> {
> struct cifs_writedata *wdata;
>
> wdata = kzalloc(sizeof(*wdata), GFP_NOFS);
> if (wdata != NULL) {
> - wdata->pages = pages;
> kref_init(&wdata->refcount);
> INIT_LIST_HEAD(&wdata->list);
> init_completion(&wdata->done);
> @@ -2558,7 +2548,6 @@ cifs_writedata_direct_alloc(struct page **pages, work_func_t complete)
> return wdata;
> }
>
> -
> static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
> {
> struct address_space *mapping = page->mapping;
> @@ -2617,6 +2606,7 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
> return rc;
> }
>
> +#if 0 // TODO: Remove for iov_iter support
> static struct cifs_writedata *
> wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
> pgoff_t end, pgoff_t *index,
> @@ -2922,6 +2912,375 @@ static int cifs_writepages(struct address_space *mapping,
> set_bit(CIFS_INO_MODIFIED_ATTR, &CIFS_I(inode)->flags);
> return rc;
> }
> +#endif
> +
> +/*
> + * Extend the region to be written back to include subsequent contiguously
> + * dirty pages if possible, but don't sleep while doing so.
> + */
> +static void cifs_extend_writeback(struct address_space *mapping,
> + long *_count,
> + loff_t start,
> + int max_pages,
> + size_t max_len,
> + unsigned int *_len)
> +{
> + struct folio_batch batch;
> + struct folio *folio;
> + unsigned int psize, nr_pages;
> + size_t len = *_len;
> + pgoff_t index = (start + len) / PAGE_SIZE;
> + bool stop = true;
> + unsigned int i;
> +
> + XA_STATE(xas, &mapping->i_pages, index);
> + folio_batch_init(&batch);
> +
> + do {
> + /* Firstly, we gather up a batch of contiguous dirty pages
> + * under the RCU read lock - but we can't clear the dirty flags
> + * there if any of those pages are mapped.
> + */
> + rcu_read_lock();
> +
> + xas_for_each(&xas, folio, ULONG_MAX) {
> + stop = true;
> + if (xas_retry(&xas, folio))
> + continue;
> + if (xa_is_value(folio))
> + break;
> + if (folio_index(folio) != index)
> + break;
> + if (!folio_try_get_rcu(folio)) {
> + xas_reset(&xas);
> + continue;
> + }
> + nr_pages = folio_nr_pages(folio);
> + if (nr_pages > max_pages)
> + break;
> +
> + /* Has the page moved or been split? */
> + if (unlikely(folio != xas_reload(&xas))) {
> + folio_put(folio);
> + break;
> + }
> +
> + if (!folio_trylock(folio)) {
> + folio_put(folio);
> + break;
> + }
> + if (!folio_test_dirty(folio) || folio_test_writeback(folio)) {
> + folio_unlock(folio);
> + folio_put(folio);
> + break;
> + }
> +
> + max_pages -= nr_pages;
> + psize = folio_size(folio);
> + len += psize;
> + stop = false;
> + if (max_pages <= 0 || len >= max_len || *_count <= 0)
> + stop = true;
> +
> + index += nr_pages;
> + if (!folio_batch_add(&batch, folio))
> + break;
> + if (stop)
> + break;
> + }
> +
> + if (!stop)
> + xas_pause(&xas);
> + rcu_read_unlock();
> +
> + /* Now, if we obtained any pages, we can shift them to being
> + * writable and mark them for caching.
> + */
> + if (!folio_batch_count(&batch))
> + break;
> +
> + for (i = 0; i < folio_batch_count(&batch); i++) {
> + folio = batch.folios[i];
> + /* The folio should be locked, dirty and not undergoing
> + * writeback from the loop above.
> + */
> + if (!folio_clear_dirty_for_io(folio))
> + WARN_ON(1);
> + if (folio_start_writeback(folio))
> + WARN_ON(1);
> +
> + *_count -= folio_nr_pages(folio);
> + folio_unlock(folio);
> + }
> +
> + folio_batch_release(&batch);
> + cond_resched();
> + } while (!stop);
> +
> + *_len = len;
> +}
> +
> +/*
> + * Write back the locked page and any subsequent non-locked dirty pages.
> + */
> +static ssize_t cifs_write_back_from_locked_folio(struct address_space *mapping,
> + struct writeback_control *wbc,
> + struct folio *folio,
> + loff_t start, loff_t end)
> +{
> + struct inode *inode = mapping->host;
> + struct TCP_Server_Info *server;
> + struct cifs_writedata *wdata;
> + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
> + struct cifs_credits credits_on_stack;
> + struct cifs_credits *credits = &credits_on_stack;
> + struct cifsFileInfo *cfile = NULL;
> + unsigned int xid, wsize, len;
> + loff_t i_size = i_size_read(inode);
> + size_t max_len;
> + long count = wbc->nr_to_write;
> + int rc;
> +
> + /* The folio should be locked, dirty and not undergoing writeback. */
> + if (folio_start_writeback(folio))
> + WARN_ON(1);
> +
> + count -= folio_nr_pages(folio);
> + len = folio_size(folio);
> +
> + xid = get_xid();
> + server = cifs_pick_channel(cifs_sb_master_tcon(cifs_sb)->ses);
> +
> + rc = cifs_get_writable_file(CIFS_I(inode), FIND_WR_ANY, &cfile);
> + if (rc) {
> + cifs_dbg(VFS, "No writable handle in writepages rc=%d\n", rc);
> + goto err_xid;
> + }
> +
> + rc = server->ops->wait_mtu_credits(server, cifs_sb->ctx->wsize,
> + &wsize, credits);
> + if (rc != 0)
> + goto err_close;
> +
> + wdata = cifs_writedata_alloc(cifs_writev_complete);
> + if (!wdata) {
> + rc = -ENOMEM;
> + goto err_uncredit;
> + }
> +
> + wdata->sync_mode = wbc->sync_mode;
> + wdata->offset = folio_pos(folio);
> + wdata->pid = cfile->pid;
> + wdata->credits = credits_on_stack;
> + wdata->cfile = cfile;
> + wdata->server = server;
> + cfile = NULL;
> +
> + /* Find all consecutive lockable dirty pages, stopping when we find a
> + * page that is not immediately lockable, is not dirty or is missing,
> + * or we reach the end of the range.
> + */
> + if (start < i_size) {
> + /* Trim the write to the EOF; the extra data is ignored. Also
> + * put an upper limit on the size of a single storedata op.
> + */
> + max_len = wsize;
> + max_len = min_t(unsigned long long, max_len, end - start + 1);
> + max_len = min_t(unsigned long long, max_len, i_size - start);
> +
> + if (len < max_len) {
> + int max_pages = INT_MAX;
> +
> +#ifdef CONFIG_CIFS_SMB_DIRECT
> + if (server->smbd_conn)
> + max_pages = server->smbd_conn->max_frmr_depth;
> +#endif
> + max_pages -= folio_nr_pages(folio);
> +
> + if (max_pages > 0)
> + cifs_extend_writeback(mapping, &count, start,
> + max_pages, max_len, &len);
> + }
> + len = min_t(loff_t, len, max_len);
> + }
> +
> + wdata->bytes = len;
> +
> + /* We now have a contiguous set of dirty pages, each with writeback
> + * set; the first page is still locked at this point, but all the rest
> + * have been unlocked.
> + */
> + folio_unlock(folio);
> +
> + if (start < i_size) {
> + iov_iter_xarray(&wdata->iter, ITER_SOURCE, &mapping->i_pages,
> + start, len);
> +
> + rc = adjust_credits(wdata->server, &wdata->credits, wdata->bytes);
> + if (rc)
> + goto err_wdata;
> +
> + if (wdata->cfile->invalidHandle)
> + rc = -EAGAIN;
> + else
> + rc = wdata->server->ops->async_writev(wdata,
> + cifs_writedata_release);
> + if (rc >= 0) {
> + kref_put(&wdata->refcount, cifs_writedata_release);
> + goto err_close;
> + }
> + } else {
> + /* The dirty region was entirely beyond the EOF. */
> + cifs_pages_written_back(inode, start, len);
> + rc = 0;
> + }
> +
> +err_wdata:
> + kref_put(&wdata->refcount, cifs_writedata_release);
> +err_uncredit:
> + add_credits_and_wake_if(server, credits, 0);
> +err_close:
> + if (cfile)
> + cifsFileInfo_put(cfile);
> +err_xid:
> + free_xid(xid);
> + if (rc == 0) {
> + wbc->nr_to_write = count;
> + } else if (is_retryable_error(rc)) {
> + cifs_pages_write_redirty(inode, start, len);
> + } else {
> + cifs_pages_write_failed(inode, start, len);
> + mapping_set_error(mapping, rc);
> + }
> + /* Indication to update ctime and mtime as close is deferred */
> + set_bit(CIFS_INO_MODIFIED_ATTR, &CIFS_I(inode)->flags);
> + return rc;
> +}
> +
> +/*
> + * write a region of pages back to the server
> + */
> +static int cifs_writepages_region(struct address_space *mapping,
> + struct writeback_control *wbc,
> + loff_t start, loff_t end, loff_t *_next)
> +{
> + struct folio *folio;
> + struct page *head_page;
> + ssize_t ret;
> + int n, skips = 0;
> +
> + do {
> + pgoff_t index = start / PAGE_SIZE;
> +
> + n = find_get_pages_range_tag(mapping, &index, end / PAGE_SIZE,
> + PAGECACHE_TAG_DIRTY, 1, &head_page);
> + if (!n)
> + break;
> +
> + folio = page_folio(head_page);
> + start = folio_pos(folio); /* May regress with THPs */
> +
> + /* At this point we hold neither the i_pages lock nor the
> + * page lock: the page may be truncated or invalidated
> + * (changing page->mapping to NULL), or even swizzled
> + * back from swapper_space to tmpfs file mapping
> + */
> + if (wbc->sync_mode != WB_SYNC_NONE) {
> + ret = folio_lock_killable(folio);
> + if (ret < 0) {
> + folio_put(folio);
> + return ret;
> + }
> + } else {
> + if (!folio_trylock(folio)) {
> + folio_put(folio);
> + return 0;
> + }
> + }
> +
> + if (folio_mapping(folio) != mapping ||
> + !folio_test_dirty(folio)) {
> + start += folio_size(folio);
> + folio_unlock(folio);
> + folio_put(folio);
> + continue;
> + }
> +
> + if (folio_test_writeback(folio) ||
> + folio_test_fscache(folio)) {
> + folio_unlock(folio);
> + if (wbc->sync_mode != WB_SYNC_NONE) {
> + folio_wait_writeback(folio);
> +#ifdef CONFIG_CIFS_FSCACHE
> + folio_wait_fscache(folio);
> +#endif
> + } else {
> + start += folio_size(folio);
> + }
> + folio_put(folio);
> + if (wbc->sync_mode == WB_SYNC_NONE) {
> + if (skips >= 5 || need_resched())
> + break;
> + skips++;
> + }
> + continue;
> + }
> +
> + if (!folio_clear_dirty_for_io(folio))
> + /* We hold the page lock - it should've been dirty. */
> + WARN_ON(1);
> +
> + ret = cifs_write_back_from_locked_folio(mapping, wbc, folio, start, end);
> + folio_put(folio);
> + if (ret < 0)
> + return ret;
> +
> + start += ret;
> + cond_resched();
> + } while (wbc->nr_to_write > 0);
> +
> + *_next = start;
> + return 0;
> +}
> +
> +/*
> + * Write some of the pending data back to the server
> + */
> +static int cifs_writepages(struct address_space *mapping,
> + struct writeback_control *wbc)
> +{
> + loff_t start, next;
> + int ret;
> +
> + /* We have to be careful as we can end up racing with setattr()
> + * truncating the pagecache since the caller doesn't take a lock here
> + * to prevent it.
> + */
> +
> + if (wbc->range_cyclic) {
> + start = mapping->writeback_index * PAGE_SIZE;
> + ret = cifs_writepages_region(mapping, wbc, start, LLONG_MAX, &next);
> + if (ret == 0) {
> + mapping->writeback_index = next / PAGE_SIZE;
> + if (start > 0 && wbc->nr_to_write > 0) {
> + ret = cifs_writepages_region(mapping, wbc, 0,
> + start, &next);
> + if (ret == 0)
> + mapping->writeback_index =
> + next / PAGE_SIZE;
> + }
> + }
> + } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
> + ret = cifs_writepages_region(mapping, wbc, 0, LLONG_MAX, &next);
> + if (wbc->nr_to_write > 0 && ret == 0)
> + mapping->writeback_index = next / PAGE_SIZE;
> + } else {
> + ret = cifs_writepages_region(mapping, wbc,
> + wbc->range_start, wbc->range_end, &next);
> + }
> +
> + return ret;
> +}
>
> static int
> cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
> @@ -2972,6 +3331,7 @@ static int cifs_write_end(struct file *file, struct address_space *mapping,
> struct inode *inode = mapping->host;
> struct cifsFileInfo *cfile = file->private_data;
> struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
> + struct folio *folio = page_folio(page);
> __u32 pid;
>
> if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
> @@ -2982,14 +3342,14 @@ static int cifs_write_end(struct file *file, struct address_space *mapping,
> cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
> page, pos, copied);
>
> - if (PageChecked(page)) {
> + if (folio_test_checked(folio)) {
> if (copied == len)
> - SetPageUptodate(page);
> - ClearPageChecked(page);
> - } else if (!PageUptodate(page) && copied == PAGE_SIZE)
> - SetPageUptodate(page);
> + folio_mark_uptodate(folio);
> + folio_clear_checked(folio);
> + } else if (!folio_test_uptodate(folio) && copied == PAGE_SIZE)
> + folio_mark_uptodate(folio);
>
> - if (!PageUptodate(page)) {
> + if (!folio_test_uptodate(folio)) {
> char *page_data;
> unsigned offset = pos & (PAGE_SIZE - 1);
> unsigned int xid;
> @@ -3149,6 +3509,7 @@ int cifs_flush(struct file *file, fl_owner_t id)
> return rc;
> }
>
> +#if 0 // TODO: Remove for iov_iter support
> static int
> cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
> {
> @@ -3189,17 +3550,15 @@ size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
>
> return num_pages;
> }
> +#endif
>
> static void
> cifs_uncached_writedata_release(struct kref *refcount)
> {
> - int i;
> struct cifs_writedata *wdata = container_of(refcount,
> struct cifs_writedata, refcount);
>
> kref_put(&wdata->ctx->refcount, cifs_aio_ctx_release);
> - for (i = 0; i < wdata->nr_pages; i++)
> - put_page(wdata->pages[i]);
> cifs_writedata_release(refcount);
> }
>
> @@ -3225,6 +3584,7 @@ cifs_uncached_writev_complete(struct work_struct *work)
> kref_put(&wdata->refcount, cifs_uncached_writedata_release);
> }
>
> +#if 0 // TODO: Remove for iov_iter support
> static int
> wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
> size_t *len, unsigned long *num_pages)
> @@ -3266,6 +3626,7 @@ wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
> *num_pages = i + 1;
> return 0;
> }
> +#endif
>
> static int
> cifs_resend_wdata(struct cifs_writedata *wdata, struct list_head *wdata_list,
> @@ -3337,23 +3698,57 @@ cifs_resend_wdata(struct cifs_writedata *wdata, struct list_head *wdata_list,
> return rc;
> }
>
> +/*
> + * Select span of a bvec iterator we're going to use. Limit it by both maximum
> + * size and maximum number of segments.
> + */
> +static size_t cifs_limit_bvec_subset(const struct iov_iter *iter, size_t max_size,
> + size_t max_segs, unsigned int *_nsegs)
> +{
> + const struct bio_vec *bvecs = iter->bvec;
> + unsigned int nbv = iter->nr_segs, ix = 0, nsegs = 0;
> + size_t len, span = 0, n = iter->count;
> + size_t skip = iter->iov_offset;
> +
> + if (WARN_ON(!iov_iter_is_bvec(iter)) || n == 0)
> + return 0;
> +
> + while (n && ix < nbv && skip) {
> + len = bvecs[ix].bv_len;
> + if (skip < len)
> + break;
> + skip -= len;
> + n -= len;
> + ix++;
> + }
> +
> + while (n && ix < nbv) {
> + len = min3(n, bvecs[ix].bv_len - skip, max_size);
> + span += len;
> + nsegs++;
> + ix++;
> + if (span >= max_size || nsegs >= max_segs)
> + break;
> + skip = 0;
> + n -= len;
> + }
> +
> + *_nsegs = nsegs;
> + return span;
> +}
> +
> static int
> -cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
> +cifs_write_from_iter(loff_t fpos, size_t len, struct iov_iter *from,
> struct cifsFileInfo *open_file,
> struct cifs_sb_info *cifs_sb, struct list_head *wdata_list,
> struct cifs_aio_ctx *ctx)
> {
> int rc = 0;
> - size_t cur_len;
> - unsigned long nr_pages, num_pages, i;
> + size_t cur_len, max_len;
> struct cifs_writedata *wdata;
> - struct iov_iter saved_from = *from;
> - loff_t saved_offset = offset;
> pid_t pid;
> struct TCP_Server_Info *server;
> - struct page **pagevec;
> - size_t start;
> - unsigned int xid;
> + unsigned int xid, max_segs = INT_MAX;
>
> if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
> pid = open_file->pid;
> @@ -3363,10 +3758,20 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
> server = cifs_pick_channel(tlink_tcon(open_file->tlink)->ses);
> xid = get_xid();
>
> +#ifdef CONFIG_CIFS_SMB_DIRECT
> + if (server->smbd_conn)
> + max_segs = server->smbd_conn->max_frmr_depth;
> +#endif
> +
> do {
> - unsigned int wsize;
> struct cifs_credits credits_on_stack;
> struct cifs_credits *credits = &credits_on_stack;
> + unsigned int wsize, nsegs = 0;
> +
> + if (signal_pending(current)) {
> + rc = -EINTR;
> + break;
> + }
>
> if (open_file->invalidHandle) {
> rc = cifs_reopen_file(open_file, false);
> @@ -3381,99 +3786,42 @@ 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_alloc2(
> - from, &pagevec, cur_len, &start);
> - if (result < 0) {
> - cifs_dbg(VFS,
> - "direct_writev couldn't get user pages (rc=%zd) iter type %d iov_offset %zd count %zd\n",
> - result, iov_iter_type(from),
> - from->iov_offset, from->count);
> - dump_stack();
> -
> - rc = result;
> - add_credits_and_wake_if(server, credits, 0);
> - break;
> - }
> - cur_len = (size_t)result;
> -
> - nr_pages =
> - (cur_len + start + PAGE_SIZE - 1) / PAGE_SIZE;
> -
> - wdata = cifs_writedata_direct_alloc(pagevec,
> - cifs_uncached_writev_complete);
> - if (!wdata) {
> - rc = -ENOMEM;
> - for (i = 0; i < nr_pages; i++)
> - put_page(pagevec[i]);
> - kvfree(pagevec);
> - add_credits_and_wake_if(server, credits, 0);
> - break;
> - }
> -
> -
> - wdata->page_offset = start;
> - wdata->tailsz =
> - nr_pages > 1 ?
> - cur_len - (PAGE_SIZE - start) -
> - (nr_pages - 2) * PAGE_SIZE :
> - cur_len;
> - } else {
> - nr_pages = get_numpages(wsize, len, &cur_len);
> - wdata = cifs_writedata_alloc(nr_pages,
> - cifs_uncached_writev_complete);
> - if (!wdata) {
> - rc = -ENOMEM;
> - add_credits_and_wake_if(server, credits, 0);
> - break;
> - }
> -
> - rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
> - if (rc) {
> - kvfree(wdata->pages);
> - kfree(wdata);
> - add_credits_and_wake_if(server, credits, 0);
> - break;
> - }
> -
> - num_pages = nr_pages;
> - rc = wdata_fill_from_iovec(
> - wdata, from, &cur_len, &num_pages);
> - if (rc) {
> - for (i = 0; i < nr_pages; i++)
> - put_page(wdata->pages[i]);
> - kvfree(wdata->pages);
> - kfree(wdata);
> - add_credits_and_wake_if(server, credits, 0);
> - break;
> - }
> + max_len = min_t(const size_t, len, wsize);
> + if (!max_len) {
> + rc = -EAGAIN;
> + add_credits_and_wake_if(server, credits, 0);
> + break;
> + }
>
> - /*
> - * Bring nr_pages down to the number of pages we
> - * actually used, and free any pages that we didn't use.
> - */
> - for ( ; nr_pages > num_pages; nr_pages--)
> - put_page(wdata->pages[nr_pages - 1]);
> + cur_len = cifs_limit_bvec_subset(from, max_len, max_segs, &nsegs);
> + cifs_dbg(FYI, "write_from_iter len=%zx/%zx nsegs=%u/%lu/%u\n",
> + cur_len, max_len, nsegs, from->nr_segs, max_segs);
> + if (cur_len == 0) {
> + rc = -EIO;
> + add_credits_and_wake_if(server, credits, 0);
> + break;
> + }
>
> - wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
> + wdata = cifs_writedata_alloc(cifs_uncached_writev_complete);
> + if (!wdata) {
> + rc = -ENOMEM;
> + add_credits_and_wake_if(server, credits, 0);
> + break;
> }
>
> wdata->sync_mode = WB_SYNC_ALL;
> - wdata->nr_pages = nr_pages;
> - wdata->offset = (__u64)offset;
> - wdata->cfile = cifsFileInfo_get(open_file);
> - wdata->server = server;
> - wdata->pid = pid;
> - wdata->bytes = cur_len;
> - wdata->pagesz = PAGE_SIZE;
> - wdata->credits = credits_on_stack;
> - wdata->ctx = ctx;
> + wdata->offset = (__u64)fpos;
> + wdata->cfile = cifsFileInfo_get(open_file);
> + wdata->server = server;
> + wdata->pid = pid;
> + wdata->bytes = cur_len;
> + wdata->credits = credits_on_stack;
> + wdata->iter = *from;
> + wdata->ctx = ctx;
> kref_get(&ctx->refcount);
>
> + iov_iter_truncate(&wdata->iter, cur_len);
> +
> rc = adjust_credits(server, &wdata->credits, wdata->bytes);
>
> if (!rc) {
> @@ -3488,16 +3836,14 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
> add_credits_and_wake_if(server, &wdata->credits, 0);
> kref_put(&wdata->refcount,
> cifs_uncached_writedata_release);
> - if (rc == -EAGAIN) {
> - *from = saved_from;
> - iov_iter_advance(from, offset - saved_offset);
> + if (rc == -EAGAIN)
> continue;
> - }
> break;
> }
>
> list_add_tail(&wdata->list, wdata_list);
> - offset += cur_len;
> + iov_iter_advance(from, cur_len);
> + fpos += cur_len;
> len -= cur_len;
> } while (len > 0);
>
> @@ -3596,8 +3942,6 @@ static ssize_t __cifs_writev(
> struct cifs_tcon *tcon;
> struct cifs_sb_info *cifs_sb;
> struct cifs_aio_ctx *ctx;
> - struct iov_iter saved_from = *from;
> - size_t len = iov_iter_count(from);
> int rc;
>
> /*
> @@ -3631,23 +3975,54 @@ static ssize_t __cifs_writev(
> ctx->iocb = iocb;
>
> ctx->pos = iocb->ki_pos;
> + ctx->direct_io = direct;
> + ctx->nr_pinned_pages = 0;
>
> - if (direct) {
> - ctx->direct_io = true;
> - ctx->iter = *from;
> - ctx->len = len;
> - } else {
> - rc = setup_aio_ctx_iter(ctx, from, ITER_SOURCE);
> - if (rc) {
> + if (user_backed_iter(from)) {
> + /*
> + * Extract IOVEC/UBUF-type iterators to a BVEC-type iterator as
> + * they contain references to the calling process's virtual
> + * memory layout which won't be available in an async worker
> + * thread. This also takes a pin on every folio involved.
> + */
> + rc = netfs_extract_user_iter(from, iov_iter_count(from),
> + &ctx->iter, 0);
> + if (rc < 0) {
> kref_put(&ctx->refcount, cifs_aio_ctx_release);
> return rc;
> }
> +
> + ctx->nr_pinned_pages = rc;
> + ctx->bv = (void *)ctx->iter.bvec;
> + ctx->bv_need_unpin = iov_iter_extract_will_pin(&ctx->iter);
> + } else if ((iov_iter_is_bvec(from) || iov_iter_is_kvec(from)) &&
> + !is_sync_kiocb(iocb)) {
> + /*
> + * If the op is asynchronous, we need to copy the list attached
> + * to a BVEC/KVEC-type iterator, but we assume that the storage
> + * will be pinned by the caller; in any case, we may or may not
> + * be able to pin the pages, so we don't try.
> + */
> + ctx->bv = (void *)dup_iter(&ctx->iter, from, GFP_KERNEL);
> + if (!ctx->bv) {
> + kref_put(&ctx->refcount, cifs_aio_ctx_release);
> + return -ENOMEM;
> + }
> + } else {
> + /*
> + * Otherwise, we just pass the iterator down as-is and rely on
> + * the caller to make sure the pages referred to by the
> + * iterator don't evaporate.
> + */
> + ctx->iter = *from;
> }
>
> + ctx->len = iov_iter_count(&ctx->iter);
> +
> /* grab a lock here due to read response handlers can access ctx */
> mutex_lock(&ctx->aio_mutex);
>
> - rc = cifs_write_from_iter(iocb->ki_pos, ctx->len, &saved_from,
> + rc = cifs_write_from_iter(iocb->ki_pos, ctx->len, &ctx->iter,
> cfile, cifs_sb, &ctx->list, ctx);
>
> /*
> @@ -3790,14 +4165,12 @@ cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
> return written;
> }
>
> -static struct cifs_readdata *
> -cifs_readdata_direct_alloc(struct page **pages, work_func_t complete)
> +static struct cifs_readdata *cifs_readdata_alloc(work_func_t complete)
> {
> struct cifs_readdata *rdata;
>
> rdata = kzalloc(sizeof(*rdata), GFP_KERNEL);
> - if (rdata != NULL) {
> - rdata->pages = pages;
> + if (rdata) {
> kref_init(&rdata->refcount);
> INIT_LIST_HEAD(&rdata->list);
> init_completion(&rdata->done);
> @@ -3807,27 +4180,14 @@ cifs_readdata_direct_alloc(struct page **pages, work_func_t complete)
> return rdata;
> }
>
> -static struct cifs_readdata *
> -cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
> -{
> - struct page **pages =
> - kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
> - struct cifs_readdata *ret = NULL;
> -
> - if (pages) {
> - ret = cifs_readdata_direct_alloc(pages, complete);
> - if (!ret)
> - kfree(pages);
> - }
> -
> - return ret;
> -}
> -
> void
> cifs_readdata_release(struct kref *refcount)
> {
> struct cifs_readdata *rdata = container_of(refcount,
> struct cifs_readdata, refcount);
> +
> + if (rdata->ctx)
> + kref_put(&rdata->ctx->refcount, cifs_aio_ctx_release);
> #ifdef CONFIG_CIFS_SMB_DIRECT
> if (rdata->mr) {
> smbd_deregister_mr(rdata->mr);
> @@ -3837,85 +4197,9 @@ cifs_readdata_release(struct kref *refcount)
> if (rdata->cfile)
> cifsFileInfo_put(rdata->cfile);
>
> - kvfree(rdata->pages);
> kfree(rdata);
> }
>
> -static int
> -cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
> -{
> - int rc = 0;
> - struct page *page;
> - unsigned int i;
> -
> - for (i = 0; i < nr_pages; i++) {
> - page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
> - if (!page) {
> - rc = -ENOMEM;
> - break;
> - }
> - rdata->pages[i] = page;
> - }
> -
> - if (rc) {
> - unsigned int nr_page_failed = i;
> -
> - for (i = 0; i < nr_page_failed; i++) {
> - put_page(rdata->pages[i]);
> - rdata->pages[i] = NULL;
> - }
> - }
> - return rc;
> -}
> -
> -static void
> -cifs_uncached_readdata_release(struct kref *refcount)
> -{
> - struct cifs_readdata *rdata = container_of(refcount,
> - struct cifs_readdata, refcount);
> - unsigned int i;
> -
> - kref_put(&rdata->ctx->refcount, cifs_aio_ctx_release);
> - for (i = 0; i < rdata->nr_pages; i++) {
> - put_page(rdata->pages[i]);
> - }
> - cifs_readdata_release(refcount);
> -}
> -
> -/**
> - * cifs_readdata_to_iov - copy data from pages in response to an iovec
> - * @rdata: the readdata response with list of pages holding data
> - * @iter: destination for our data
> - *
> - * This function copies data from a list of pages in a readdata response into
> - * an array of iovecs. It will first calculate where the data should go
> - * based on the info in the readdata and then copy the data into that spot.
> - */
> -static int
> -cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
> -{
> - size_t remaining = rdata->got_bytes;
> - unsigned int i;
> -
> - for (i = 0; i < rdata->nr_pages; i++) {
> - struct page *page = rdata->pages[i];
> - size_t copy = min_t(size_t, remaining, PAGE_SIZE);
> - size_t written;
> -
> - if (unlikely(iov_iter_is_pipe(iter))) {
> - void *addr = kmap_atomic(page);
> -
> - written = copy_to_iter(addr, copy, iter);
> - kunmap_atomic(addr);
> - } else
> - written = copy_page_to_iter(page, 0, copy, iter);
> - remaining -= written;
> - if (written < copy && iov_iter_count(iter) > 0)
> - break;
> - }
> - return remaining ? -EFAULT : 0;
> -}
> -
> static void collect_uncached_read_data(struct cifs_aio_ctx *ctx);
>
> static void
> @@ -3927,9 +4211,11 @@ cifs_uncached_readv_complete(struct work_struct *work)
> complete(&rdata->done);
> collect_uncached_read_data(rdata->ctx);
> /* the below call can possibly free the last ref to aio ctx */
> - kref_put(&rdata->refcount, cifs_uncached_readdata_release);
> + kref_put(&rdata->refcount, cifs_readdata_release);
> }
>
> +#if 0 // TODO: Remove for iov_iter support
> +
> static int
> uncached_fill_pages(struct TCP_Server_Info *server,
> struct cifs_readdata *rdata, struct iov_iter *iter,
> @@ -4003,6 +4289,7 @@ cifs_uncached_copy_into_pages(struct TCP_Server_Info *server,
> {
> return uncached_fill_pages(server, rdata, iter, iter->count);
> }
> +#endif
>
> static int cifs_resend_rdata(struct cifs_readdata *rdata,
> struct list_head *rdata_list,
> @@ -4072,37 +4359,36 @@ static int cifs_resend_rdata(struct cifs_readdata *rdata,
> } while (rc == -EAGAIN);
>
> fail:
> - kref_put(&rdata->refcount, cifs_uncached_readdata_release);
> + kref_put(&rdata->refcount, cifs_readdata_release);
> return rc;
> }
>
> static int
> -cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
> +cifs_send_async_read(loff_t fpos, size_t len, struct cifsFileInfo *open_file,
> struct cifs_sb_info *cifs_sb, struct list_head *rdata_list,
> struct cifs_aio_ctx *ctx)
> {
> struct cifs_readdata *rdata;
> - unsigned int npages, rsize;
> + unsigned int rsize, nsegs, max_segs = INT_MAX;
> struct cifs_credits credits_on_stack;
> struct cifs_credits *credits = &credits_on_stack;
> - size_t cur_len;
> + size_t cur_len, max_len;
> int rc;
> pid_t pid;
> struct TCP_Server_Info *server;
> - struct page **pagevec;
> - size_t start;
> - struct iov_iter direct_iov = ctx->iter;
>
> server = cifs_pick_channel(tlink_tcon(open_file->tlink)->ses);
>
> +#ifdef CONFIG_CIFS_SMB_DIRECT
> + if (server->smbd_conn)
> + max_segs = server->smbd_conn->max_frmr_depth;
> +#endif
> +
> if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
> pid = open_file->pid;
> else
> pid = current->tgid;
>
> - if (ctx->direct_io)
> - iov_iter_advance(&direct_iov, offset - ctx->pos);
> -
> do {
> if (open_file->invalidHandle) {
> rc = cifs_reopen_file(open_file, true);
> @@ -4122,78 +4408,37 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
> if (rc)
> break;
>
> - cur_len = min_t(const size_t, len, rsize);
> -
> - if (ctx->direct_io) {
> - ssize_t result;
> -
> - result = iov_iter_get_pages_alloc2(
> - &direct_iov, &pagevec,
> - cur_len, &start);
> - if (result < 0) {
> - cifs_dbg(VFS,
> - "Couldn't get user pages (rc=%zd) iter type %d iov_offset %zd count %zd\n",
> - result, iov_iter_type(&direct_iov),
> - direct_iov.iov_offset,
> - direct_iov.count);
> - dump_stack();
> -
> - rc = result;
> - add_credits_and_wake_if(server, credits, 0);
> - break;
> - }
> - cur_len = (size_t)result;
> -
> - rdata = cifs_readdata_direct_alloc(
> - pagevec, cifs_uncached_readv_complete);
> - if (!rdata) {
> - add_credits_and_wake_if(server, credits, 0);
> - rc = -ENOMEM;
> - break;
> - }
> -
> - npages = (cur_len + start + PAGE_SIZE-1) / PAGE_SIZE;
> - rdata->page_offset = start;
> - rdata->tailsz = npages > 1 ?
> - cur_len-(PAGE_SIZE-start)-(npages-2)*PAGE_SIZE :
> - cur_len;
> -
> - } else {
> -
> - npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
> - /* allocate a readdata struct */
> - rdata = cifs_readdata_alloc(npages,
> - cifs_uncached_readv_complete);
> - if (!rdata) {
> - add_credits_and_wake_if(server, credits, 0);
> - rc = -ENOMEM;
> - break;
> - }
> + max_len = min_t(size_t, len, rsize);
>
> - rc = cifs_read_allocate_pages(rdata, npages);
> - if (rc) {
> - kvfree(rdata->pages);
> - kfree(rdata);
> - add_credits_and_wake_if(server, credits, 0);
> - break;
> - }
> + cur_len = cifs_limit_bvec_subset(&ctx->iter, max_len,
> + max_segs, &nsegs);
> + cifs_dbg(FYI, "read-to-iter len=%zx/%zx nsegs=%u/%lu/%u\n",
> + cur_len, max_len, nsegs, ctx->iter.nr_segs, max_segs);
> + if (cur_len == 0) {
> + rc = -EIO;
> + add_credits_and_wake_if(server, credits, 0);
> + break;
> + }
>
> - rdata->tailsz = PAGE_SIZE;
> + rdata = cifs_readdata_alloc(cifs_uncached_readv_complete);
> + if (!rdata) {
> + add_credits_and_wake_if(server, credits, 0);
> + rc = -ENOMEM;
> + break;
> }
>
> - rdata->server = server;
> - rdata->cfile = cifsFileInfo_get(open_file);
> - rdata->nr_pages = npages;
> - rdata->offset = offset;
> - rdata->bytes = cur_len;
> - rdata->pid = pid;
> - rdata->pagesz = PAGE_SIZE;
> - rdata->read_into_pages = cifs_uncached_read_into_pages;
> - rdata->copy_into_pages = cifs_uncached_copy_into_pages;
> - rdata->credits = credits_on_stack;
> - rdata->ctx = ctx;
> + rdata->server = server;
> + rdata->cfile = cifsFileInfo_get(open_file);
> + rdata->offset = fpos;
> + rdata->bytes = cur_len;
> + rdata->pid = pid;
> + rdata->credits = credits_on_stack;
> + rdata->ctx = ctx;
> kref_get(&ctx->refcount);
>
> + rdata->iter = ctx->iter;
> + iov_iter_truncate(&rdata->iter, cur_len);
> +
> rc = adjust_credits(server, &rdata->credits, rdata->bytes);
>
> if (!rc) {
> @@ -4205,17 +4450,15 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
>
> if (rc) {
> add_credits_and_wake_if(server, &rdata->credits, 0);
> - kref_put(&rdata->refcount,
> - cifs_uncached_readdata_release);
> - if (rc == -EAGAIN) {
> - iov_iter_revert(&direct_iov, cur_len);
> + kref_put(&rdata->refcount, cifs_readdata_release);
> + if (rc == -EAGAIN)
> continue;
> - }
> break;
> }
>
> list_add_tail(&rdata->list, rdata_list);
> - offset += cur_len;
> + iov_iter_advance(&ctx->iter, cur_len);
> + fpos += cur_len;
> len -= cur_len;
> } while (len > 0);
>
> @@ -4257,22 +4500,6 @@ collect_uncached_read_data(struct cifs_aio_ctx *ctx)
> list_del_init(&rdata->list);
> INIT_LIST_HEAD(&tmp_list);
>
> - /*
> - * Got a part of data and then reconnect has
> - * happened -- fill the buffer and continue
> - * reading.
> - */
> - if (got_bytes && got_bytes < rdata->bytes) {
> - rc = 0;
> - if (!ctx->direct_io)
> - rc = cifs_readdata_to_iov(rdata, to);
> - if (rc) {
> - kref_put(&rdata->refcount,
> - cifs_uncached_readdata_release);
> - continue;
> - }
> - }
> -
> if (ctx->direct_io) {
> /*
> * Re-use rdata as this is a
> @@ -4289,7 +4516,7 @@ collect_uncached_read_data(struct cifs_aio_ctx *ctx)
> &tmp_list, ctx);
>
> kref_put(&rdata->refcount,
> - cifs_uncached_readdata_release);
> + cifs_readdata_release);
> }
>
> list_splice(&tmp_list, &ctx->list);
> @@ -4297,8 +4524,6 @@ collect_uncached_read_data(struct cifs_aio_ctx *ctx)
> goto again;
> } else if (rdata->result)
> rc = rdata->result;
> - else if (!ctx->direct_io)
> - rc = cifs_readdata_to_iov(rdata, to);
>
> /* if there was a short read -- discard anything left */
> if (rdata->got_bytes && rdata->got_bytes < rdata->bytes)
> @@ -4307,7 +4532,7 @@ collect_uncached_read_data(struct cifs_aio_ctx *ctx)
> ctx->total_len += rdata->got_bytes;
> }
> list_del_init(&rdata->list);
> - kref_put(&rdata->refcount, cifs_uncached_readdata_release);
> + kref_put(&rdata->refcount, cifs_readdata_release);
> }
>
> if (!ctx->direct_io)
> @@ -4367,26 +4592,53 @@ static ssize_t __cifs_readv(
> if (!ctx)
> return -ENOMEM;
>
> - ctx->cfile = cifsFileInfo_get(cfile);
> + ctx->pos = offset;
> + ctx->direct_io = direct;
> + ctx->len = len;
> + ctx->cfile = cifsFileInfo_get(cfile);
> + ctx->nr_pinned_pages = 0;
>
> if (!is_sync_kiocb(iocb))
> ctx->iocb = iocb;
>
> - if (user_backed_iter(to))
> - ctx->should_dirty = true;
> -
> - if (direct) {
> - ctx->pos = offset;
> - ctx->direct_io = true;
> - ctx->iter = *to;
> - ctx->len = len;
> - } else {
> - rc = setup_aio_ctx_iter(ctx, to, ITER_DEST);
> - if (rc) {
> + if (user_backed_iter(to)) {
> + /*
> + * Extract IOVEC/UBUF-type iterators to a BVEC-type iterator as
> + * they contain references to the calling process's virtual
> + * memory layout which won't be available in an async worker
> + * thread. This also takes a pin on every folio involved.
> + */
> + rc = netfs_extract_user_iter(to, iov_iter_count(to),
> + &ctx->iter, 0);
> + if (rc < 0) {
> kref_put(&ctx->refcount, cifs_aio_ctx_release);
> return rc;
> }
> - len = ctx->len;
> +
> + ctx->nr_pinned_pages = rc;
> + ctx->bv = (void *)ctx->iter.bvec;
> + ctx->bv_need_unpin = iov_iter_extract_will_pin(&ctx->iter);
> + ctx->should_dirty = true;
> + } else if ((iov_iter_is_bvec(to) || iov_iter_is_kvec(to)) &&
> + !is_sync_kiocb(iocb)) {
> + /*
> + * If the op is asynchronous, we need to copy the list attached
> + * to a BVEC/KVEC-type iterator, but we assume that the storage
> + * will be retained by the caller; in any case, we may or may
> + * not be able to pin the pages, so we don't try.
> + */
> + ctx->bv = (void *)dup_iter(&ctx->iter, to, GFP_KERNEL);
> + if (!ctx->bv) {
> + kref_put(&ctx->refcount, cifs_aio_ctx_release);
> + return -ENOMEM;
> + }
> + } else {
> + /*
> + * Otherwise, we just pass the iterator down as-is and rely on
> + * the caller to make sure the pages referred to by the
> + * iterator don't evaporate.
> + */
> + ctx->iter = *to;
> }
>
> if (direct) {
> @@ -4648,6 +4900,8 @@ int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
> return rc;
> }
>
> +#if 0 // TODO: Remove for iov_iter support
> +
> static void
> cifs_readv_complete(struct work_struct *work)
> {
> @@ -4778,19 +5032,74 @@ cifs_readpages_copy_into_pages(struct TCP_Server_Info *server,
> {
> return readpages_fill_pages(server, rdata, iter, iter->count);
> }
> +#endif
> +
> +/*
> + * Unlock a bunch of folios in the pagecache.
> + */
> +static void cifs_unlock_folios(struct address_space *mapping, pgoff_t first, pgoff_t last)
> +{
> + struct folio *folio;
> + XA_STATE(xas, &mapping->i_pages, first);
> +
> + rcu_read_lock();
> + xas_for_each(&xas, folio, last) {
> + folio_unlock(folio);
> + }
> + rcu_read_unlock();
> +}
> +
> +static void cifs_readahead_complete(struct work_struct *work)
> +{
> + struct cifs_readdata *rdata = container_of(work,
> + struct cifs_readdata, work);
> + struct folio *folio;
> + pgoff_t last;
> + bool good = rdata->result == 0 || (rdata->result == -EAGAIN && rdata->got_bytes);
> +
> + XA_STATE(xas, &rdata->mapping->i_pages, rdata->offset / PAGE_SIZE);
> +
> + if (good)
> + cifs_readahead_to_fscache(rdata->mapping->host,
> + rdata->offset, rdata->bytes);
> +
> + if (iov_iter_count(&rdata->iter) > 0)
> + iov_iter_zero(iov_iter_count(&rdata->iter), &rdata->iter);
> +
> + last = (rdata->offset + rdata->bytes - 1) / PAGE_SIZE;
> +
> + rcu_read_lock();
> + xas_for_each(&xas, folio, last) {
> + if (good) {
> + flush_dcache_folio(folio);
> + folio_mark_uptodate(folio);
> + }
> + folio_unlock(folio);
> + }
> + rcu_read_unlock();
> +
> + kref_put(&rdata->refcount, cifs_readdata_release);
> +}
>
> static void cifs_readahead(struct readahead_control *ractl)
> {
> - int rc;
> struct cifsFileInfo *open_file = ractl->file->private_data;
> struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(ractl->file);
> struct TCP_Server_Info *server;
> - pid_t pid;
> - unsigned int xid, nr_pages, last_batch_size = 0, cache_nr_pages = 0;
> - pgoff_t next_cached = ULONG_MAX;
> + unsigned int xid, nr_pages, cache_nr_pages = 0;
> + unsigned int ra_pages;
> + pgoff_t next_cached = ULONG_MAX, ra_index;
> bool caching = fscache_cookie_enabled(cifs_inode_cookie(ractl->mapping->host)) &&
> cifs_inode_cookie(ractl->mapping->host)->cache_priv;
> bool check_cache = caching;
> + pid_t pid;
> + int rc = 0;
> +
> + /* Note that readahead_count() lags behind our dequeuing of pages from
> + * the ractl, wo we have to keep track for ourselves.
> + */
> + ra_pages = readahead_count(ractl);
> + ra_index = readahead_index(ractl);
>
> xid = get_xid();
>
> @@ -4799,22 +5108,21 @@ static void cifs_readahead(struct readahead_control *ractl)
> else
> pid = current->tgid;
>
> - rc = 0;
> server = cifs_pick_channel(tlink_tcon(open_file->tlink)->ses);
>
> cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
> - __func__, ractl->file, ractl->mapping, readahead_count(ractl));
> + __func__, ractl->file, ractl->mapping, ra_pages);
>
> /*
> * Chop the readahead request up into rsize-sized read requests.
> */
> - while ((nr_pages = readahead_count(ractl) - last_batch_size)) {
> - unsigned int i, got, rsize;
> - struct page *page;
> + while ((nr_pages = ra_pages)) {
> + unsigned int i, rsize;
> struct cifs_readdata *rdata;
> struct cifs_credits credits_on_stack;
> struct cifs_credits *credits = &credits_on_stack;
> - pgoff_t index = readahead_index(ractl) + last_batch_size;
> + struct folio *folio;
> + pgoff_t fsize;
>
> /*
> * Find out if we have anything cached in the range of
> @@ -4823,21 +5131,22 @@ static void cifs_readahead(struct readahead_control *ractl)
> if (caching) {
> if (check_cache) {
> rc = cifs_fscache_query_occupancy(
> - ractl->mapping->host, index, nr_pages,
> + ractl->mapping->host, ra_index, nr_pages,
> &next_cached, &cache_nr_pages);
> if (rc < 0)
> caching = false;
> check_cache = false;
> }
>
> - if (index == next_cached) {
> + if (ra_index == next_cached) {
> /*
> * TODO: Send a whole batch of pages to be read
> * by the cache.
> */
> - struct folio *folio = readahead_folio(ractl);
> -
> - last_batch_size = folio_nr_pages(folio);
> + folio = readahead_folio(ractl);
> + fsize = folio_nr_pages(folio);
> + ra_pages -= fsize;
> + ra_index += fsize;
> if (cifs_readpage_from_fscache(ractl->mapping->host,
> &folio->page) < 0) {
> /*
> @@ -4848,8 +5157,8 @@ static void cifs_readahead(struct readahead_control *ractl)
> caching = false;
> }
> folio_unlock(folio);
> - next_cached++;
> - cache_nr_pages--;
> + next_cached += fsize;
> + cache_nr_pages -= fsize;
> if (cache_nr_pages == 0)
> check_cache = true;
> continue;
> @@ -4874,8 +5183,9 @@ static void cifs_readahead(struct readahead_control *ractl)
> &rsize, credits);
> if (rc)
> break;
> - nr_pages = min_t(size_t, rsize / PAGE_SIZE, readahead_count(ractl));
> - nr_pages = min_t(size_t, nr_pages, next_cached - index);
> + nr_pages = min_t(size_t, rsize / PAGE_SIZE, ra_pages);
> + if (next_cached != ULONG_MAX)
> + nr_pages = min_t(size_t, nr_pages, next_cached - ra_index);
>
> /*
> * Give up immediately if rsize is too small to read an entire
> @@ -4888,33 +5198,31 @@ static void cifs_readahead(struct readahead_control *ractl)
> break;
> }
>
> - rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
> + rdata = cifs_readdata_alloc(cifs_readahead_complete);
> if (!rdata) {
> /* best to give up if we're out of mem */
> add_credits_and_wake_if(server, credits, 0);
> break;
> }
>
> - got = __readahead_batch(ractl, rdata->pages, nr_pages);
> - if (got != nr_pages) {
> - pr_warn("__readahead_batch() returned %u/%u\n",
> - got, nr_pages);
> - nr_pages = got;
> - }
> -
> - rdata->nr_pages = nr_pages;
> - rdata->bytes = readahead_batch_length(ractl);
> + rdata->offset = ra_index * PAGE_SIZE;
> + rdata->bytes = nr_pages * PAGE_SIZE;
> rdata->cfile = cifsFileInfo_get(open_file);
> rdata->server = server;
> rdata->mapping = ractl->mapping;
> - rdata->offset = readahead_pos(ractl);
> rdata->pid = pid;
> - rdata->pagesz = PAGE_SIZE;
> - rdata->tailsz = PAGE_SIZE;
> - rdata->read_into_pages = cifs_readpages_read_into_pages;
> - rdata->copy_into_pages = cifs_readpages_copy_into_pages;
> rdata->credits = credits_on_stack;
>
> + for (i = 0; i < nr_pages; i++) {
> + if (!readahead_folio(ractl))
> + WARN_ON(1);
> + }
> + ra_pages -= nr_pages;
> + ra_index += nr_pages;
> +
> + iov_iter_xarray(&rdata->iter, ITER_DEST, &rdata->mapping->i_pages,
> + rdata->offset, rdata->bytes);
> +
> rc = adjust_credits(server, &rdata->credits, rdata->bytes);
> if (!rc) {
> if (rdata->cfile->invalidHandle)
> @@ -4925,18 +5233,15 @@ static void cifs_readahead(struct readahead_control *ractl)
>
> if (rc) {
> add_credits_and_wake_if(server, &rdata->credits, 0);
> - for (i = 0; i < rdata->nr_pages; i++) {
> - page = rdata->pages[i];
> - unlock_page(page);
> - put_page(page);
> - }
> + cifs_unlock_folios(rdata->mapping,
> + rdata->offset / PAGE_SIZE,
> + (rdata->offset + rdata->bytes - 1) / PAGE_SIZE);
> /* Fallback to the readpage in error/reconnect cases */
> kref_put(&rdata->refcount, cifs_readdata_release);
> break;
> }
>
> kref_put(&rdata->refcount, cifs_readdata_release);
> - last_batch_size = nr_pages;
> }
>
> free_xid(xid);
> @@ -4978,10 +5283,6 @@ static int cifs_readpage_worker(struct file *file, struct page *page,
>
> flush_dcache_page(page);
> SetPageUptodate(page);
> -
> - /* send this page to the cache */
> - cifs_readpage_to_fscache(file_inode(file), page);
> -
> rc = 0;
>
> io_error:
> diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
> index f6f3a6b75601..47c9f36c11fb 100644
> --- a/fs/cifs/fscache.c
> +++ b/fs/cifs/fscache.c
> @@ -165,22 +165,16 @@ static int fscache_fallback_read_page(struct inode *inode, struct page *page)
> /*
> * Fallback page writing interface.
> */
> -static int fscache_fallback_write_page(struct inode *inode, struct page *page,
> - bool no_space_allocated_yet)
> +static int fscache_fallback_write_pages(struct inode *inode, loff_t start, size_t len,
> + bool no_space_allocated_yet)
> {
> struct netfs_cache_resources cres;
> struct fscache_cookie *cookie = cifs_inode_cookie(inode);
> struct iov_iter iter;
> - struct bio_vec bvec[1];
> - loff_t start = page_offset(page);
> - size_t len = PAGE_SIZE;
> int ret;
>
> memset(&cres, 0, sizeof(cres));
> - bvec[0].bv_page = page;
> - bvec[0].bv_offset = 0;
> - bvec[0].bv_len = PAGE_SIZE;
> - iov_iter_bvec(&iter, ITER_SOURCE, bvec, ARRAY_SIZE(bvec), PAGE_SIZE);
> + iov_iter_xarray(&iter, ITER_SOURCE, &inode->i_mapping->i_pages, start, len);
>
> ret = fscache_begin_write_operation(&cres, cookie);
> if (ret < 0)
> @@ -189,7 +183,7 @@ static int fscache_fallback_write_page(struct inode *inode, struct page *page,
> ret = cres.ops->prepare_write(&cres, &start, &len, i_size_read(inode),
> no_space_allocated_yet);
> if (ret == 0)
> - ret = fscache_write(&cres, page_offset(page), &iter, NULL, NULL);
> + ret = fscache_write(&cres, start, &iter, NULL, NULL);
> fscache_end_operation(&cres);
> return ret;
> }
> @@ -213,12 +207,12 @@ int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)
> return 0;
> }
>
> -void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
> +void __cifs_readahead_to_fscache(struct inode *inode, loff_t pos, size_t len)
> {
> - cifs_dbg(FYI, "%s: (fsc: %p, p: %p, i: %p)\n",
> - __func__, cifs_inode_cookie(inode), page, inode);
> + cifs_dbg(FYI, "%s: (fsc: %p, p: %llx, l: %zx, i: %p)\n",
> + __func__, cifs_inode_cookie(inode), pos, len, inode);
>
> - fscache_fallback_write_page(inode, page, true);
> + fscache_fallback_write_pages(inode, pos, len, true);
> }
>
> /*
> diff --git a/fs/cifs/fscache.h b/fs/cifs/fscache.h
> index 67b601041f0a..173999610997 100644
> --- a/fs/cifs/fscache.h
> +++ b/fs/cifs/fscache.h
> @@ -90,7 +90,7 @@ static inline int cifs_fscache_query_occupancy(struct inode *inode,
> }
>
> extern int __cifs_readpage_from_fscache(struct inode *pinode, struct page *ppage);
> -extern void __cifs_readpage_to_fscache(struct inode *pinode, struct page *ppage);
> +extern void __cifs_readahead_to_fscache(struct inode *pinode, loff_t pos, size_t len);
>
>
> static inline int cifs_readpage_from_fscache(struct inode *inode,
> @@ -101,11 +101,11 @@ static inline int cifs_readpage_from_fscache(struct inode *inode,
> return -ENOBUFS;
> }
>
> -static inline void cifs_readpage_to_fscache(struct inode *inode,
> - struct page *page)
> +static inline void cifs_readahead_to_fscache(struct inode *inode,
> + loff_t pos, size_t len)
> {
> if (cifs_inode_cookie(inode))
> - __cifs_readpage_to_fscache(inode, page);
> + __cifs_readahead_to_fscache(inode, pos, len);
> }
>
> #else /* CONFIG_CIFS_FSCACHE */
> @@ -141,7 +141,7 @@ cifs_readpage_from_fscache(struct inode *inode, struct page *page)
> }
>
> static inline
> -void cifs_readpage_to_fscache(struct inode *inode, struct page *page) {}
> +void cifs_readahead_to_fscache(struct inode *inode, loff_t pos, size_t len) {}
>
> #endif /* CONFIG_CIFS_FSCACHE */
>
> diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
> index 2a19c7987c5b..967bc3b74def 100644
> --- a/fs/cifs/misc.c
> +++ b/fs/cifs/misc.c
> @@ -966,16 +966,22 @@ cifs_aio_ctx_release(struct kref *refcount)
>
> /*
> * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly
> - * which means that iov_iter_get_pages() was a success and thus that
> - * we have taken reference on pages.
> + * which means that iov_iter_extract_pages() was a success and thus
> + * that we may have references or pins on pages that we need to
> + * release.
> */
> if (ctx->bv) {
> - unsigned i;
> + if (ctx->should_dirty || ctx->bv_need_unpin) {
> + unsigned i;
>
> - for (i = 0; i < ctx->npages; i++) {
> - if (ctx->should_dirty)
> - set_page_dirty(ctx->bv[i].bv_page);
> - put_page(ctx->bv[i].bv_page);
> + for (i = 0; i < ctx->nr_pinned_pages; i++) {
> + struct page *page = ctx->bv[i].bv_page;
> +
> + if (ctx->should_dirty)
> + set_page_dirty(page);
> + if (ctx->bv_need_unpin)
> + unpin_user_page(page);
> + }
> }
> kvfree(ctx->bv);
> }
> @@ -983,95 +989,6 @@ cifs_aio_ctx_release(struct kref *refcount)
> kfree(ctx);
> }
>
> -#define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
> -
> -int
> -setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
> -{
> - ssize_t rc;
> - unsigned int cur_npages;
> - unsigned int npages = 0;
> - unsigned int i;
> - size_t len;
> - size_t count = iov_iter_count(iter);
> - unsigned int saved_len;
> - size_t start;
> - unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
> - struct page **pages = NULL;
> - struct bio_vec *bv = NULL;
> -
> - if (iov_iter_is_kvec(iter)) {
> - memcpy(&ctx->iter, iter, sizeof(*iter));
> - ctx->len = count;
> - iov_iter_advance(iter, count);
> - return 0;
> - }
> -
> - if (array_size(max_pages, sizeof(*bv)) <= CIFS_AIO_KMALLOC_LIMIT)
> - bv = kmalloc_array(max_pages, sizeof(*bv), GFP_KERNEL);
> -
> - if (!bv) {
> - bv = vmalloc(array_size(max_pages, sizeof(*bv)));
> - if (!bv)
> - return -ENOMEM;
> - }
> -
> - if (array_size(max_pages, sizeof(*pages)) <= CIFS_AIO_KMALLOC_LIMIT)
> - pages = kmalloc_array(max_pages, sizeof(*pages), GFP_KERNEL);
> -
> - if (!pages) {
> - pages = vmalloc(array_size(max_pages, sizeof(*pages)));
> - if (!pages) {
> - kvfree(bv);
> - return -ENOMEM;
> - }
> - }
> -
> - saved_len = count;
> -
> - while (count && npages < max_pages) {
> - rc = iov_iter_get_pages2(iter, pages, count, max_pages, &start);
> - if (rc < 0) {
> - cifs_dbg(VFS, "Couldn't get user pages (rc=%zd)\n", rc);
> - break;
> - }
> -
> - if (rc > count) {
> - cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
> - count);
> - break;
> - }
> -
> - count -= rc;
> - rc += start;
> - cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
> -
> - if (npages + cur_npages > max_pages) {
> - cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
> - npages + cur_npages, max_pages);
> - break;
> - }
> -
> - for (i = 0; i < cur_npages; i++) {
> - len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
> - bv[npages + i].bv_page = pages[i];
> - bv[npages + i].bv_offset = start;
> - bv[npages + i].bv_len = len - start;
> - rc -= len;
> - start = 0;
> - }
> -
> - npages += cur_npages;
> - }
> -
> - kvfree(pages);
> - ctx->bv = bv;
> - ctx->len = saved_len - count;
> - ctx->npages = npages;
> - iov_iter_bvec(&ctx->iter, rw, ctx->bv, npages, ctx->len);
> - return 0;
> -}
> -
> /**
> * cifs_alloc_hash - allocate hash and hash context together
> * @name: The name of the crypto hash algo
> @@ -1129,25 +1046,6 @@ cifs_free_hash(struct shash_desc **sdesc)
> *sdesc = NULL;
> }
>
> -/**
> - * rqst_page_get_length - obtain the length and offset for a page in smb_rqst
> - * @rqst: The request descriptor
> - * @page: The index of the page to query
> - * @len: Where to store the length for this page:
> - * @offset: Where to store the offset for this page
> - */
> -void rqst_page_get_length(const struct smb_rqst *rqst, unsigned int page,
> - unsigned int *len, unsigned int *offset)
> -{
> - *len = rqst->rq_pagesz;
> - *offset = (page == 0) ? rqst->rq_offset : 0;
> -
> - if (rqst->rq_npages == 1 || page == rqst->rq_npages-1)
> - *len = rqst->rq_tailsz;
> - else if (page == 0)
> - *len = rqst->rq_pagesz - rqst->rq_offset;
> -}
> -
> void extract_unc_hostname(const char *unc, const char **h, size_t *len)
> {
> const char *end;
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index 665ccf8d979d..121faf3b2900 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -4244,7 +4244,7 @@ fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, unsigned int orig_len,
>
> static void *smb2_aead_req_alloc(struct crypto_aead *tfm, const struct smb_rqst *rqst,
> int num_rqst, const u8 *sig, u8 **iv,
> - struct aead_request **req, struct scatterlist **sgl,
> + struct aead_request **req, struct sg_table *sgt,
> unsigned int *num_sgs)
> {
> unsigned int req_size = sizeof(**req) + crypto_aead_reqsize(tfm);
> @@ -4253,43 +4253,42 @@ static void *smb2_aead_req_alloc(struct crypto_aead *tfm, const struct smb_rqst
> u8 *p;
>
> *num_sgs = cifs_get_num_sgs(rqst, num_rqst, sig);
> + if (IS_ERR_VALUE((long)(int)*num_sgs))
> + return ERR_PTR(*num_sgs);
>
> len = iv_size;
> len += crypto_aead_alignmask(tfm) & ~(crypto_tfm_ctx_alignment() - 1);
> len = ALIGN(len, crypto_tfm_ctx_alignment());
> len += req_size;
> len = ALIGN(len, __alignof__(struct scatterlist));
> - len += *num_sgs * sizeof(**sgl);
> + len += array_size(*num_sgs, sizeof(struct scatterlist));
>
> - p = kmalloc(len, GFP_ATOMIC);
> + p = kvzalloc(len, GFP_NOFS);
> if (!p)
> - return NULL;
> + return ERR_PTR(-ENOMEM);
>
> *iv = (u8 *)PTR_ALIGN(p, crypto_aead_alignmask(tfm) + 1);
> *req = (struct aead_request *)PTR_ALIGN(*iv + iv_size,
> crypto_tfm_ctx_alignment());
> - *sgl = (struct scatterlist *)PTR_ALIGN((u8 *)*req + req_size,
> - __alignof__(struct scatterlist));
> + sgt->sgl = (struct scatterlist *)PTR_ALIGN((u8 *)*req + req_size,
> + __alignof__(struct scatterlist));
> return p;
> }
>
> -static void *smb2_get_aead_req(struct crypto_aead *tfm, const struct smb_rqst *rqst,
> +static void *smb2_get_aead_req(struct crypto_aead *tfm, struct smb_rqst *rqst,
> int num_rqst, const u8 *sig, u8 **iv,
> struct aead_request **req, struct scatterlist **sgl)
> {
> - unsigned int off, len, skip;
> - struct scatterlist *sg;
> - unsigned int num_sgs;
> - unsigned long addr;
> - int i, j;
> + struct sg_table sgtable = {};
> + unsigned int skip, num_sgs, i, j;
> + ssize_t rc;
> void *p;
>
> - p = smb2_aead_req_alloc(tfm, rqst, num_rqst, sig, iv, req, sgl, &num_sgs);
> - if (!p)
> - return NULL;
> + p = smb2_aead_req_alloc(tfm, rqst, num_rqst, sig, iv, req, &sgtable, &num_sgs);
> + if (IS_ERR(p))
> + return ERR_CAST(p);
>
> - sg_init_table(*sgl, num_sgs);
> - sg = *sgl;
> + sg_init_marker(sgtable.sgl, num_sgs);
>
> /*
> * The first rqst has a transform header where the
> @@ -4297,30 +4296,29 @@ static void *smb2_get_aead_req(struct crypto_aead *tfm, const struct smb_rqst *r
> */
> skip = 20;
>
> - /* Assumes the first rqst has a transform header as the first iov.
> - * I.e.
> - * rqst[0].rq_iov[0] is transform header
> - * rqst[0].rq_iov[1+] data to be encrypted/decrypted
> - * rqst[1+].rq_iov[0+] data to be encrypted/decrypted
> - */
> for (i = 0; i < num_rqst; i++) {
> - for (j = 0; j < rqst[i].rq_nvec; j++) {
> - struct kvec *iov = &rqst[i].rq_iov[j];
> + struct iov_iter *iter = &rqst[i].rq_iter;
> + size_t count = iov_iter_count(iter);
>
> - addr = (unsigned long)iov->iov_base + skip;
> - len = iov->iov_len - skip;
> - sg = cifs_sg_set_buf(sg, (void *)addr, len);
> + for (j = 0; j < rqst[i].rq_nvec; j++) {
> + cifs_sg_set_buf(&sgtable,
> + rqst[i].rq_iov[j].iov_base + skip,
> + rqst[i].rq_iov[j].iov_len - skip);
>
> /* See the above comment on the 'skip' assignment */
> skip = 0;
> }
> - for (j = 0; j < rqst[i].rq_npages; j++) {
> - rqst_page_get_length(&rqst[i], j, &len, &off);
> - sg_set_page(sg++, rqst[i].rq_pages[j], len, off);
> - }
> + sgtable.orig_nents = sgtable.nents;
> +
> + rc = netfs_extract_iter_to_sg(iter, count, &sgtable,
> + num_sgs - sgtable.nents, 0);
> + iov_iter_revert(iter, rc);
> + sgtable.orig_nents = sgtable.nents;
> }
> - cifs_sg_set_buf(sg, sig, SMB2_SIGNATURE_SIZE);
>
> + cifs_sg_set_buf(&sgtable, sig, SMB2_SIGNATURE_SIZE);
> + sg_mark_end(&sgtable.sgl[sgtable.nents - 1]);
> + *sgl = sgtable.sgl;
> return p;
> }
>
> @@ -4408,8 +4406,8 @@ crypt_message(struct TCP_Server_Info *server, int num_rqst,
> }
>
> creq = smb2_get_aead_req(tfm, rqst, num_rqst, sign, &iv, &req, &sg);
> - if (unlikely(!creq))
> - return -ENOMEM;
> + if (unlikely(IS_ERR(creq)))
> + return PTR_ERR(creq);
>
> if (!enc) {
> memcpy(sign, &tr_hdr->Signature, SMB2_SIGNATURE_SIZE);
> @@ -4441,18 +4439,31 @@ crypt_message(struct TCP_Server_Info *server, int num_rqst,
> return rc;
> }
>
> +/*
> + * Clear a read buffer, discarding the folios which have XA_MARK_0 set.
> + */
> +static void cifs_clear_xarray_buffer(struct xarray *buffer)
> +{
> + struct folio *folio;
> +
> + XA_STATE(xas, buffer, 0);
> +
> + rcu_read_lock();
> + xas_for_each_marked(&xas, folio, ULONG_MAX, XA_MARK_0) {
> + folio_put(folio);
> + }
> + rcu_read_unlock();
> + xa_destroy(buffer);
> +}
> +
> void
> smb3_free_compound_rqst(int num_rqst, struct smb_rqst *rqst)
> {
> - int i, j;
> + int i;
>
> - for (i = 0; i < num_rqst; i++) {
> - if (rqst[i].rq_pages) {
> - for (j = rqst[i].rq_npages - 1; j >= 0; j--)
> - put_page(rqst[i].rq_pages[j]);
> - kfree(rqst[i].rq_pages);
> - }
> - }
> + for (i = 0; i < num_rqst; i++)
> + if (!xa_empty(&rqst[i].rq_buffer))
> + cifs_clear_xarray_buffer(&rqst[i].rq_buffer);
> }
>
> /*
> @@ -4472,9 +4483,8 @@ static int
> smb3_init_transform_rq(struct TCP_Server_Info *server, int num_rqst,
> struct smb_rqst *new_rq, struct smb_rqst *old_rq)
> {
> - struct page **pages;
> struct smb2_transform_hdr *tr_hdr = new_rq[0].rq_iov[0].iov_base;
> - unsigned int npages;
> + struct page *page;
> unsigned int orig_len = 0;
> int i, j;
> int rc = -ENOMEM;
> @@ -4482,40 +4492,43 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, int num_rqst,
> for (i = 1; i < num_rqst; i++) {
> struct smb_rqst *old = &old_rq[i - 1];
> struct smb_rqst *new = &new_rq[i];
> + struct xarray *buffer = &new->rq_buffer;
> + size_t size = iov_iter_count(&old->rq_iter), seg, copied = 0;
>
> orig_len += smb_rqst_len(server, old);
> new->rq_iov = old->rq_iov;
> new->rq_nvec = old->rq_nvec;
>
> - npages = old->rq_npages;
> - if (!npages)
> - continue;
> -
> - pages = kmalloc_array(npages, sizeof(struct page *),
> - GFP_KERNEL);
> - if (!pages)
> - goto err_free;
> -
> - new->rq_pages = pages;
> - new->rq_npages = npages;
> - new->rq_offset = old->rq_offset;
> - new->rq_pagesz = old->rq_pagesz;
> - new->rq_tailsz = old->rq_tailsz;
> -
> - for (j = 0; j < npages; j++) {
> - pages[j] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
> - if (!pages[j])
> - goto err_free;
> - }
> + xa_init(buffer);
>
> - /* copy pages form the old */
> - for (j = 0; j < npages; j++) {
> - unsigned int offset, len;
> + if (size > 0) {
> + unsigned int npages = DIV_ROUND_UP(size, PAGE_SIZE);
>
> - rqst_page_get_length(new, j, &len, &offset);
> + for (j = 0; j < npages; j++) {
> + void *o;
>
> - memcpy_page(new->rq_pages[j], offset,
> - old->rq_pages[j], offset, len);
> + rc = -ENOMEM;
> + page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
> + if (!page)
> + goto err_free;
> + page->index = j;
> + o = xa_store(buffer, j, page, GFP_KERNEL);
> + if (xa_is_err(o)) {
> + rc = xa_err(o);
> + put_page(page);
> + goto err_free;
> + }
> +
> + seg = min_t(size_t, size - copied, PAGE_SIZE);
> + if (copy_page_from_iter(page, 0, seg, &old->rq_iter) != seg) {
> + rc = -EFAULT;
> + goto err_free;
> + }
> + copied += seg;
> + }
> + iov_iter_xarray(&new->rq_iter, ITER_SOURCE,
> + buffer, 0, size);
> + new->rq_iter_size = size;
> }
> }
>
> @@ -4544,12 +4557,12 @@ smb3_is_transform_hdr(void *buf)
>
> static int
> decrypt_raw_data(struct TCP_Server_Info *server, char *buf,
> - unsigned int buf_data_size, struct page **pages,
> - unsigned int npages, unsigned int page_data_size,
> + unsigned int buf_data_size, struct iov_iter *iter,
> bool is_offloaded)
> {
> struct kvec iov[2];
> struct smb_rqst rqst = {NULL};
> + size_t iter_size = 0;
> int rc;
>
> iov[0].iov_base = buf;
> @@ -4559,10 +4572,11 @@ decrypt_raw_data(struct TCP_Server_Info *server, char *buf,
>
> rqst.rq_iov = iov;
> rqst.rq_nvec = 2;
> - rqst.rq_pages = pages;
> - rqst.rq_npages = npages;
> - rqst.rq_pagesz = PAGE_SIZE;
> - rqst.rq_tailsz = (page_data_size % PAGE_SIZE) ? : PAGE_SIZE;
> + if (iter) {
> + rqst.rq_iter = *iter;
> + rqst.rq_iter_size = iov_iter_count(iter);
> + iter_size = iov_iter_count(iter);
> + }
>
> rc = crypt_message(server, 1, &rqst, 0);
> cifs_dbg(FYI, "Decrypt message returned %d\n", rc);
> @@ -4573,73 +4587,37 @@ decrypt_raw_data(struct TCP_Server_Info *server, char *buf,
> memmove(buf, iov[1].iov_base, buf_data_size);
>
> if (!is_offloaded)
> - server->total_read = buf_data_size + page_data_size;
> + server->total_read = buf_data_size + iter_size;
>
> return rc;
> }
>
> static int
> -read_data_into_pages(struct TCP_Server_Info *server, struct page **pages,
> - unsigned int npages, unsigned int len)
> +cifs_copy_pages_to_iter(struct xarray *pages, unsigned int data_size,
> + unsigned int skip, struct iov_iter *iter)
> {
> - int i;
> - int length;
> + struct page *page;
> + unsigned long index;
>
> - for (i = 0; i < npages; i++) {
> - struct page *page = pages[i];
> - size_t n;
> + xa_for_each(pages, index, page) {
> + size_t n, len = min_t(unsigned int, PAGE_SIZE - skip, data_size);
>
> - n = len;
> - if (len >= PAGE_SIZE) {
> - /* enough data to fill the page */
> - n = PAGE_SIZE;
> - len -= n;
> - } else {
> - zero_user(page, len, PAGE_SIZE - len);
> - len = 0;
> + n = copy_page_to_iter(page, skip, len, iter);
> + if (n != len) {
> + cifs_dbg(VFS, "%s: something went wrong\n", __func__);
> + return -EIO;
> }
> - length = cifs_read_page_from_socket(server, page, 0, n);
> - if (length < 0)
> - return length;
> - server->total_read += length;
> - }
> -
> - return 0;
> -}
> -
> -static int
> -init_read_bvec(struct page **pages, unsigned int npages, unsigned int data_size,
> - unsigned int cur_off, struct bio_vec **page_vec)
> -{
> - struct bio_vec *bvec;
> - int i;
> -
> - bvec = kcalloc(npages, sizeof(struct bio_vec), GFP_KERNEL);
> - if (!bvec)
> - return -ENOMEM;
> -
> - for (i = 0; i < npages; i++) {
> - bvec[i].bv_page = pages[i];
> - bvec[i].bv_offset = (i == 0) ? cur_off : 0;
> - bvec[i].bv_len = min_t(unsigned int, PAGE_SIZE, data_size);
> - data_size -= bvec[i].bv_len;
> - }
> -
> - if (data_size != 0) {
> - cifs_dbg(VFS, "%s: something went wrong\n", __func__);
> - kfree(bvec);
> - return -EIO;
> + data_size -= n;
> + skip = 0;
> }
>
> - *page_vec = bvec;
> return 0;
> }
>
> static int
> handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
> - char *buf, unsigned int buf_len, struct page **pages,
> - unsigned int npages, unsigned int page_data_size,
> - bool is_offloaded)
> + char *buf, unsigned int buf_len, struct xarray *pages,
> + unsigned int pages_len, bool is_offloaded)
> {
> unsigned int data_offset;
> unsigned int data_len;
> @@ -4648,9 +4626,6 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
> unsigned int pad_len;
> struct cifs_readdata *rdata = mid->callback_data;
> struct smb2_hdr *shdr = (struct smb2_hdr *)buf;
> - struct bio_vec *bvec = NULL;
> - struct iov_iter iter;
> - struct kvec iov;
> int length;
> bool use_rdma_mr = false;
>
> @@ -4739,7 +4714,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
> return 0;
> }
>
> - if (data_len > page_data_size - pad_len) {
> + if (data_len > pages_len - pad_len) {
> /* data_len is corrupt -- discard frame */
> rdata->result = -EIO;
> if (is_offloaded)
> @@ -4749,8 +4724,9 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
> return 0;
> }
>
> - rdata->result = init_read_bvec(pages, npages, page_data_size,
> - cur_off, &bvec);
> + /* Copy the data to the output I/O iterator. */
> + rdata->result = cifs_copy_pages_to_iter(pages, pages_len,
> + cur_off, &rdata->iter);
> if (rdata->result != 0) {
> if (is_offloaded)
> mid->mid_state = MID_RESPONSE_MALFORMED;
> @@ -4758,14 +4734,16 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
> dequeue_mid(mid, rdata->result);
> return 0;
> }
> + rdata->got_bytes = pages_len;
>
> - iov_iter_bvec(&iter, ITER_SOURCE, bvec, npages, data_len);
> } else if (buf_len >= data_offset + data_len) {
> /* read response payload is in buf */
> - WARN_ONCE(npages > 0, "read data can be either in buf or in pages");
> - iov.iov_base = buf + data_offset;
> - iov.iov_len = data_len;
> - iov_iter_kvec(&iter, ITER_SOURCE, &iov, 1, data_len);
> + WARN_ONCE(pages && !xa_empty(pages),
> + "read data can be either in buf or in pages");
> + length = copy_to_iter(buf + data_offset, data_len, &rdata->iter);
> + if (length < 0)
> + return length;
> + rdata->got_bytes = data_len;
> } else {
> /* read response payload cannot be in both buf and pages */
> WARN_ONCE(1, "buf can not contain only a part of read data");
> @@ -4777,26 +4755,18 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
> return 0;
> }
>
> - length = rdata->copy_into_pages(server, rdata, &iter);
> -
> - kfree(bvec);
> -
> - if (length < 0)
> - return length;
> -
> if (is_offloaded)
> mid->mid_state = MID_RESPONSE_RECEIVED;
> else
> dequeue_mid(mid, false);
> - return length;
> + return 0;
> }
>
> struct smb2_decrypt_work {
> struct work_struct decrypt;
> struct TCP_Server_Info *server;
> - struct page **ppages;
> + struct xarray buffer;
> char *buf;
> - unsigned int npages;
> unsigned int len;
> };
>
> @@ -4805,11 +4775,13 @@ static void smb2_decrypt_offload(struct work_struct *work)
> {
> struct smb2_decrypt_work *dw = container_of(work,
> struct smb2_decrypt_work, decrypt);
> - int i, rc;
> + int rc;
> struct mid_q_entry *mid;
> + struct iov_iter iter;
>
> + iov_iter_xarray(&iter, ITER_DEST, &dw->buffer, 0, dw->len);
> rc = decrypt_raw_data(dw->server, dw->buf, dw->server->vals->read_rsp_size,
> - dw->ppages, dw->npages, dw->len, true);
> + &iter, true);
> if (rc) {
> cifs_dbg(VFS, "error decrypting rc=%d\n", rc);
> goto free_pages;
> @@ -4823,7 +4795,7 @@ static void smb2_decrypt_offload(struct work_struct *work)
> mid->decrypted = true;
> rc = handle_read_data(dw->server, mid, dw->buf,
> dw->server->vals->read_rsp_size,
> - dw->ppages, dw->npages, dw->len,
> + &dw->buffer, dw->len,
> true);
> if (rc >= 0) {
> #ifdef CONFIG_CIFS_STATS2
> @@ -4856,10 +4828,7 @@ static void smb2_decrypt_offload(struct work_struct *work)
> }
>
> free_pages:
> - for (i = dw->npages-1; i >= 0; i--)
> - put_page(dw->ppages[i]);
> -
> - kfree(dw->ppages);
> + cifs_clear_xarray_buffer(&dw->buffer);
> cifs_small_buf_release(dw->buf);
> kfree(dw);
> }
> @@ -4869,47 +4838,65 @@ static int
> receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid,
> int *num_mids)
> {
> + struct page *page;
> char *buf = server->smallbuf;
> struct smb2_transform_hdr *tr_hdr = (struct smb2_transform_hdr *)buf;
> - unsigned int npages;
> - struct page **pages;
> - unsigned int len;
> + struct iov_iter iter;
> + unsigned int len, npages;
> unsigned int buflen = server->pdu_size;
> int rc;
> int i = 0;
> struct smb2_decrypt_work *dw;
>
> + dw = kzalloc(sizeof(struct smb2_decrypt_work), GFP_KERNEL);
> + if (!dw)
> + return -ENOMEM;
> + xa_init(&dw->buffer);
> + INIT_WORK(&dw->decrypt, smb2_decrypt_offload);
> + dw->server = server;
> +
> *num_mids = 1;
> len = min_t(unsigned int, buflen, server->vals->read_rsp_size +
> sizeof(struct smb2_transform_hdr)) - HEADER_SIZE(server) + 1;
>
> rc = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1, len);
> if (rc < 0)
> - return rc;
> + goto free_dw;
> server->total_read += rc;
>
> len = le32_to_cpu(tr_hdr->OriginalMessageSize) -
> server->vals->read_rsp_size;
> + dw->len = len;
> npages = DIV_ROUND_UP(len, PAGE_SIZE);
>
> - pages = kmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
> - if (!pages) {
> - rc = -ENOMEM;
> - goto discard_data;
> - }
> -
> + rc = -ENOMEM;
> for (; i < npages; i++) {
> - pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
> - if (!pages[i]) {
> - rc = -ENOMEM;
> + void *old;
> +
> + page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
> + if (!page)
> + goto discard_data;
> + page->index = i;
> + old = xa_store(&dw->buffer, i, page, GFP_KERNEL);
> + if (xa_is_err(old)) {
> + rc = xa_err(old);
> + put_page(page);
> goto discard_data;
> }
> }
>
> - /* read read data into pages */
> - rc = read_data_into_pages(server, pages, npages, len);
> - if (rc)
> - goto free_pages;
> + iov_iter_xarray(&iter, ITER_DEST, &dw->buffer, 0, npages * PAGE_SIZE);
> +
> + /* Read the data into the buffer and clear excess bufferage. */
> + rc = cifs_read_iter_from_socket(server, &iter, dw->len);
> + if (rc < 0)
> + goto discard_data;
> +
> + server->total_read += rc;
> + if (rc < npages * PAGE_SIZE)
> + iov_iter_zero(npages * PAGE_SIZE - rc, &iter);
> + iov_iter_revert(&iter, npages * PAGE_SIZE);
> + iov_iter_truncate(&iter, dw->len);
>
> rc = cifs_discard_remaining_data(server);
> if (rc)
> @@ -4922,39 +4909,28 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid,
>
> if ((server->min_offload) && (server->in_flight > 1) &&
> (server->pdu_size >= server->min_offload)) {
> - dw = kmalloc(sizeof(struct smb2_decrypt_work), GFP_KERNEL);
> - if (dw == NULL)
> - goto non_offloaded_decrypt;
> -
> dw->buf = server->smallbuf;
> server->smallbuf = (char *)cifs_small_buf_get();
>
> - INIT_WORK(&dw->decrypt, smb2_decrypt_offload);
> -
> - dw->npages = npages;
> - dw->server = server;
> - dw->ppages = pages;
> - dw->len = len;
> queue_work(decrypt_wq, &dw->decrypt);
> *num_mids = 0; /* worker thread takes care of finding mid */
> return -1;
> }
>
> -non_offloaded_decrypt:
> rc = decrypt_raw_data(server, buf, server->vals->read_rsp_size,
> - pages, npages, len, false);
> + &iter, false);
> if (rc)
> goto free_pages;
>
> *mid = smb2_find_mid(server, buf);
> - if (*mid == NULL)
> + if (*mid == NULL) {
> cifs_dbg(FYI, "mid not found\n");
> - else {
> + } else {
> cifs_dbg(FYI, "mid found\n");
> (*mid)->decrypted = true;
> rc = handle_read_data(server, *mid, buf,
> server->vals->read_rsp_size,
> - pages, npages, len, false);
> + &dw->buffer, dw->len, false);
> if (rc >= 0) {
> if (server->ops->is_network_name_deleted) {
> server->ops->is_network_name_deleted(buf,
> @@ -4964,9 +4940,9 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid,
> }
>
> free_pages:
> - for (i = i - 1; i >= 0; i--)
> - put_page(pages[i]);
> - kfree(pages);
> + cifs_clear_xarray_buffer(&dw->buffer);
> +free_dw:
> + kfree(dw);
> return rc;
> discard_data:
> cifs_discard_remaining_data(server);
> @@ -5004,7 +4980,7 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
> server->total_read += length;
>
> buf_size = pdu_length - sizeof(struct smb2_transform_hdr);
> - length = decrypt_raw_data(server, buf, buf_size, NULL, 0, 0, false);
> + length = decrypt_raw_data(server, buf, buf_size, NULL, false);
> if (length)
> return length;
>
> @@ -5103,7 +5079,7 @@ smb3_handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid)
> char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
>
> return handle_read_data(server, mid, buf, server->pdu_size,
> - NULL, 0, 0, false);
> + NULL, 0, false);
> }
>
> static int
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index b16b41d35560..541d8174afb9 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -4140,10 +4140,8 @@ smb2_new_read_req(void **buf, unsigned int *total_len,
> struct smbd_buffer_descriptor_v1 *v1;
> bool need_invalidate = server->dialect == SMB30_PROT_ID;
>
> - rdata->mr = smbd_register_mr(
> - server->smbd_conn, rdata->pages,
> - rdata->nr_pages, rdata->page_offset,
> - rdata->tailsz, true, need_invalidate);
> + rdata->mr = smbd_register_mr(server->smbd_conn, &rdata->iter,
> + true, need_invalidate);
> if (!rdata->mr)
> return -EAGAIN;
>
> @@ -4200,15 +4198,9 @@ smb2_readv_callback(struct mid_q_entry *mid)
> (struct smb2_hdr *)rdata->iov[0].iov_base;
> struct cifs_credits credits = { .value = 0, .instance = 0 };
> struct smb_rqst rqst = { .rq_iov = &rdata->iov[1],
> - .rq_nvec = 1, };
> -
> - if (rdata->got_bytes) {
> - rqst.rq_pages = rdata->pages;
> - rqst.rq_offset = rdata->page_offset;
> - rqst.rq_npages = rdata->nr_pages;
> - rqst.rq_pagesz = rdata->pagesz;
> - rqst.rq_tailsz = rdata->tailsz;
> - }
> + .rq_nvec = 1,
> + .rq_iter = rdata->iter,
> + .rq_iter_size = iov_iter_count(&rdata->iter), };
>
> WARN_ONCE(rdata->server != mid->server,
> "rdata server %p != mid server %p",
> @@ -4226,6 +4218,8 @@ smb2_readv_callback(struct mid_q_entry *mid)
> if (server->sign && !mid->decrypted) {
> int rc;
>
> + iov_iter_revert(&rqst.rq_iter, rdata->got_bytes);
> + iov_iter_truncate(&rqst.rq_iter, rdata->got_bytes);
> rc = smb2_verify_signature(&rqst, server);
> if (rc)
> cifs_tcon_dbg(VFS, "SMB signature verification returned error = %d\n",
> @@ -4568,7 +4562,7 @@ smb2_async_writev(struct cifs_writedata *wdata,
> req->VolatileFileId = io_parms->volatile_fid;
> req->WriteChannelInfoOffset = 0;
> req->WriteChannelInfoLength = 0;
> - req->Channel = 0;
> + req->Channel = SMB2_CHANNEL_NONE;
> req->Offset = cpu_to_le64(io_parms->offset);
> req->DataOffset = cpu_to_le16(
> offsetof(struct smb2_write_req, Buffer));
> @@ -4588,26 +4582,18 @@ smb2_async_writev(struct cifs_writedata *wdata,
> */
> if (smb3_use_rdma_offload(io_parms)) {
> struct smbd_buffer_descriptor_v1 *v1;
> + size_t data_size = iov_iter_count(&wdata->iter);
> bool need_invalidate = server->dialect == SMB30_PROT_ID;
>
> - wdata->mr = smbd_register_mr(
> - server->smbd_conn, wdata->pages,
> - wdata->nr_pages, wdata->page_offset,
> - wdata->tailsz, false, need_invalidate);
> + wdata->mr = smbd_register_mr(server->smbd_conn, &wdata->iter,
> + false, need_invalidate);
> if (!wdata->mr) {
> rc = -EAGAIN;
> goto async_writev_out;
> }
> req->Length = 0;
> req->DataOffset = 0;
> - if (wdata->nr_pages > 1)
> - req->RemainingBytes =
> - cpu_to_le32(
> - (wdata->nr_pages - 1) * wdata->pagesz -
> - wdata->page_offset + wdata->tailsz
> - );
> - else
> - req->RemainingBytes = cpu_to_le32(wdata->tailsz);
> + req->RemainingBytes = cpu_to_le32(data_size);
> req->Channel = SMB2_CHANNEL_RDMA_V1_INVALIDATE;
> if (need_invalidate)
> req->Channel = SMB2_CHANNEL_RDMA_V1;
> @@ -4626,19 +4612,14 @@ smb2_async_writev(struct cifs_writedata *wdata,
>
> rqst.rq_iov = iov;
> rqst.rq_nvec = 1;
> - rqst.rq_pages = wdata->pages;
> - rqst.rq_offset = wdata->page_offset;
> - rqst.rq_npages = wdata->nr_pages;
> - rqst.rq_pagesz = wdata->pagesz;
> - rqst.rq_tailsz = wdata->tailsz;
> + rqst.rq_iter = wdata->iter;
> + rqst.rq_iter_size = iov_iter_count(&rqst.rq_iter);
> #ifdef CONFIG_CIFS_SMB_DIRECT
> - if (wdata->mr) {
> + if (wdata->mr)
> iov[0].iov_len += sizeof(struct smbd_buffer_descriptor_v1);
> - rqst.rq_npages = 0;
> - }
> #endif
> - cifs_dbg(FYI, "async write at %llu %u bytes\n",
> - io_parms->offset, io_parms->length);
> + cifs_dbg(FYI, "async write at %llu %u bytes iter=%zx\n",
> + io_parms->offset, io_parms->length, iov_iter_count(&rqst.rq_iter));
>
> #ifdef CONFIG_CIFS_SMB_DIRECT
> /* For RDMA read, I/O size is in RemainingBytes not in Length */
> diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
> index 3e0aacddc291..0eb32bbfc467 100644
> --- a/fs/cifs/smbdirect.c
> +++ b/fs/cifs/smbdirect.c
> @@ -34,12 +34,6 @@ static int smbd_post_recv(
> struct smbd_response *response);
>
> static int smbd_post_send_empty(struct smbd_connection *info);
> -static int smbd_post_send_data(
> - struct smbd_connection *info,
> - struct kvec *iov, int n_vec, int remaining_data_length);
> -static int smbd_post_send_page(struct smbd_connection *info,
> - struct page *page, unsigned long offset,
> - size_t size, int remaining_data_length);
>
> static void destroy_mr_list(struct smbd_connection *info);
> static int allocate_mr_list(struct smbd_connection *info);
> @@ -986,24 +980,6 @@ static int smbd_post_send_sgl(struct smbd_connection *info,
> return rc;
> }
>
> -/*
> - * Send a page
> - * page: the page to send
> - * offset: offset in the page to send
> - * size: length in the page to send
> - * remaining_data_length: remaining data to send in this payload
> - */
> -static int smbd_post_send_page(struct smbd_connection *info, struct page *page,
> - unsigned long offset, size_t size, int remaining_data_length)
> -{
> - struct scatterlist sgl;
> -
> - sg_init_table(&sgl, 1);
> - sg_set_page(&sgl, page, size, offset);
> -
> - return smbd_post_send_sgl(info, &sgl, size, remaining_data_length);
> -}
> -
> /*
> * Send an empty message
> * Empty message is used to extend credits to peer to for keep live
> @@ -1015,35 +991,6 @@ static int smbd_post_send_empty(struct smbd_connection *info)
> return smbd_post_send_sgl(info, NULL, 0, 0);
> }
>
> -/*
> - * Send a data buffer
> - * iov: the iov array describing the data buffers
> - * n_vec: number of iov array
> - * remaining_data_length: remaining data to send following this packet
> - * in segmented SMBD packet
> - */
> -static int smbd_post_send_data(
> - struct smbd_connection *info, struct kvec *iov, int n_vec,
> - int remaining_data_length)
> -{
> - int i;
> - u32 data_length = 0;
> - struct scatterlist sgl[SMBDIRECT_MAX_SEND_SGE - 1];
> -
> - if (n_vec > SMBDIRECT_MAX_SEND_SGE - 1) {
> - cifs_dbg(VFS, "Can't fit data to SGL, n_vec=%d\n", n_vec);
> - return -EINVAL;
> - }
> -
> - sg_init_table(sgl, n_vec);
> - for (i = 0; i < n_vec; i++) {
> - data_length += iov[i].iov_len;
> - sg_set_buf(&sgl[i], iov[i].iov_base, iov[i].iov_len);
> - }
> -
> - return smbd_post_send_sgl(info, sgl, data_length, remaining_data_length);
> -}
> -
> /*
> * Post a receive request to the transport
> * The remote peer can only send data when a receive request is posted
> @@ -1986,6 +1933,42 @@ int smbd_recv(struct smbd_connection *info, struct msghdr *msg)
> return rc;
> }
>
> +/*
> + * Send the contents of an iterator
> + * @iter: The iterator to send
> + * @_remaining_data_length: remaining data to send in this payload
> + */
> +static int smbd_post_send_iter(struct smbd_connection *info,
> + struct iov_iter *iter,
> + int *_remaining_data_length)
> +{
> + struct scatterlist sgl[SMBDIRECT_MAX_SEND_SGE - 1];
> + unsigned int max_payload = info->max_send_size - sizeof(struct smbd_data_transfer);
> + ssize_t rc;
> +
> + /* We're not expecting a user-backed iter */
> + WARN_ON(iov_iter_extract_will_pin(iter));
> +
> + do {
> + struct sg_table sgtable = { .sgl = sgl };
> + size_t maxlen = min_t(size_t, *_remaining_data_length, max_payload);
> +
> + sg_init_table(sgtable.sgl, ARRAY_SIZE(sgl));
> + rc = netfs_extract_iter_to_sg(iter, maxlen,
> + &sgtable, ARRAY_SIZE(sgl), 0);
> + if (rc < 0)
> + break;
> + if (WARN_ON_ONCE(sgtable.nents == 0))
> + return -EIO;
> +
> + sg_mark_end(&sgl[sgtable.nents - 1]);
> + *_remaining_data_length -= rc;
> + rc = smbd_post_send_sgl(info, sgl, rc, *_remaining_data_length);
> + } while (rc == 0 && iov_iter_count(iter) > 0);
> +
> + return rc;
> +}
> +
> /*
> * Send data to transport
> * Each rqst is transported as a SMBDirect payload
> @@ -1996,18 +1979,10 @@ int smbd_send(struct TCP_Server_Info *server,
> int num_rqst, struct smb_rqst *rqst_array)
> {
> struct smbd_connection *info = server->smbd_conn;
> - struct kvec vecs[SMBDIRECT_MAX_SEND_SGE - 1];
> - int nvecs;
> - int size;
> - unsigned int buflen, remaining_data_length;
> - unsigned int offset, remaining_vec_data_length;
> - int start, i, j;
> - int max_iov_size =
> - info->max_send_size - sizeof(struct smbd_data_transfer);
> - struct kvec *iov;
> - int rc;
> struct smb_rqst *rqst;
> - int rqst_idx;
> + struct iov_iter iter;
> + unsigned int remaining_data_length, klen;
> + int rc, i, rqst_idx;
>
> if (info->transport_status != SMBD_CONNECTED)
> return -EAGAIN;
> @@ -2034,84 +2009,36 @@ int smbd_send(struct TCP_Server_Info *server,
> rqst_idx = 0;
> do {
> rqst = &rqst_array[rqst_idx];
> - iov = rqst->rq_iov;
>
> cifs_dbg(FYI, "Sending smb (RDMA): idx=%d smb_len=%lu\n",
> - rqst_idx, smb_rqst_len(server, rqst));
> - remaining_vec_data_length = 0;
> - for (i = 0; i < rqst->rq_nvec; i++) {
> - remaining_vec_data_length += iov[i].iov_len;
> - dump_smb(iov[i].iov_base, iov[i].iov_len);
> - }
> -
> - log_write(INFO, "rqst_idx=%d nvec=%d rqst->rq_npages=%d rq_pagesz=%d rq_tailsz=%d buflen=%lu\n",
> - rqst_idx, rqst->rq_nvec,
> - rqst->rq_npages, rqst->rq_pagesz,
> - rqst->rq_tailsz, smb_rqst_len(server, rqst));
> -
> - start = 0;
> - offset = 0;
> - do {
> - buflen = 0;
> - i = start;
> - j = 0;
> - while (i < rqst->rq_nvec &&
> - j < SMBDIRECT_MAX_SEND_SGE - 1 &&
> - buflen < max_iov_size) {
> -
> - vecs[j].iov_base = iov[i].iov_base + offset;
> - if (buflen + iov[i].iov_len > max_iov_size) {
> - vecs[j].iov_len =
> - max_iov_size - iov[i].iov_len;
> - buflen = max_iov_size;
> - offset = vecs[j].iov_len;
> - } else {
> - vecs[j].iov_len =
> - iov[i].iov_len - offset;
> - buflen += vecs[j].iov_len;
> - offset = 0;
> - ++i;
> - }
> - ++j;
> - }
> + rqst_idx, smb_rqst_len(server, rqst));
> + for (i = 0; i < rqst->rq_nvec; i++)
> + dump_smb(rqst->rq_iov[i].iov_base, rqst->rq_iov[i].iov_len);
> +
> + log_write(INFO, "RDMA-WR[%u] nvec=%d len=%u iter=%zu rqlen=%lu\n",
> + rqst_idx, rqst->rq_nvec, remaining_data_length,
> + iov_iter_count(&rqst->rq_iter), smb_rqst_len(server, rqst));
> +
> + /* Send the metadata pages. */
> + klen = 0;
> + for (i = 0; i < rqst->rq_nvec; i++)
> + klen += rqst->rq_iov[i].iov_len;
> + iov_iter_kvec(&iter, ITER_SOURCE, rqst->rq_iov, rqst->rq_nvec, klen);
> +
> + rc = smbd_post_send_iter(info, &iter, &remaining_data_length);
> + if (rc < 0)
> + break;
>
> - remaining_vec_data_length -= buflen;
> - remaining_data_length -= buflen;
> - log_write(INFO, "sending %s iov[%d] from start=%d nvecs=%d remaining_data_length=%d\n",
> - remaining_vec_data_length > 0 ?
> - "partial" : "complete",
> - rqst->rq_nvec, start, j,
> - remaining_data_length);
> -
> - start = i;
> - rc = smbd_post_send_data(info, vecs, j, remaining_data_length);
> - if (rc)
> - goto done;
> - } while (remaining_vec_data_length > 0);
> -
> - /* now sending pages if there are any */
> - for (i = 0; i < rqst->rq_npages; i++) {
> - rqst_page_get_length(rqst, i, &buflen, &offset);
> - nvecs = (buflen + max_iov_size - 1) / max_iov_size;
> - log_write(INFO, "sending pages buflen=%d nvecs=%d\n",
> - buflen, nvecs);
> - for (j = 0; j < nvecs; j++) {
> - size = min_t(unsigned int, max_iov_size, remaining_data_length);
> - remaining_data_length -= size;
> - log_write(INFO, "sending pages i=%d offset=%d size=%d remaining_data_length=%d\n",
> - i, j * max_iov_size + offset, size,
> - remaining_data_length);
> - rc = smbd_post_send_page(
> - info, rqst->rq_pages[i],
> - j*max_iov_size + offset,
> - size, remaining_data_length);
> - if (rc)
> - goto done;
> - }
> + if (iov_iter_count(&rqst->rq_iter) > 0) {
> + /* And then the data pages if there are any */
> + rc = smbd_post_send_iter(info, &rqst->rq_iter,
> + &remaining_data_length);
> + if (rc < 0)
> + break;
> }
> +
> } while (++rqst_idx < num_rqst);
>
> -done:
> /*
> * As an optimization, we don't wait for individual I/O to finish
> * before sending the next one.
> @@ -2315,27 +2242,48 @@ static struct smbd_mr *get_mr(struct smbd_connection *info)
> goto again;
> }
>
> +/*
> + * Transcribe the pages from an iterator into an MR scatterlist.
> + * @iter: The iterator to transcribe
> + * @_remaining_data_length: remaining data to send in this payload
> + */
> +static int smbd_iter_to_mr(struct smbd_connection *info,
> + struct iov_iter *iter,
> + struct scatterlist *sgl,
> + unsigned int num_pages)
> +{
> + struct sg_table sgtable = { .sgl = sgl };
> + int ret;
> +
> + sg_init_table(sgl, num_pages);
> +
> + ret = netfs_extract_iter_to_sg(iter, iov_iter_count(iter),
> + &sgtable, num_pages, 0);
> + WARN_ON(ret < 0);
> + return ret;
> +}
> +
> /*
> * Register memory for RDMA read/write
> - * pages[]: the list of pages to register memory with
> - * num_pages: the number of pages to register
> - * tailsz: if non-zero, the bytes to register in the last page
> + * iter: the buffer to register memory with
> * writing: true if this is a RDMA write (SMB read), false for RDMA read
> * need_invalidate: true if this MR needs to be locally invalidated after I/O
> * return value: the MR registered, NULL if failed.
> */
> -struct smbd_mr *smbd_register_mr(
> - struct smbd_connection *info, struct page *pages[], int num_pages,
> - int offset, int tailsz, bool writing, bool need_invalidate)
> +struct smbd_mr *smbd_register_mr(struct smbd_connection *info,
> + struct iov_iter *iter,
> + bool writing, bool need_invalidate)
> {
> struct smbd_mr *smbdirect_mr;
> - int rc, i;
> + int rc, num_pages;
> enum dma_data_direction dir;
> struct ib_reg_wr *reg_wr;
>
> + num_pages = iov_iter_npages(iter, info->max_frmr_depth + 1);
> if (num_pages > info->max_frmr_depth) {
> log_rdma_mr(ERR, "num_pages=%d max_frmr_depth=%d\n",
> num_pages, info->max_frmr_depth);
> + WARN_ON_ONCE(1);
> return NULL;
> }
>
> @@ -2344,32 +2292,16 @@ struct smbd_mr *smbd_register_mr(
> log_rdma_mr(ERR, "get_mr returning NULL\n");
> return NULL;
> }
> +
> + dir = writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
> + smbdirect_mr->dir = dir;
> smbdirect_mr->need_invalidate = need_invalidate;
> smbdirect_mr->sgl_count = num_pages;
> - sg_init_table(smbdirect_mr->sgl, num_pages);
> -
> - log_rdma_mr(INFO, "num_pages=0x%x offset=0x%x tailsz=0x%x\n",
> - num_pages, offset, tailsz);
> -
> - if (num_pages == 1) {
> - sg_set_page(&smbdirect_mr->sgl[0], pages[0], tailsz, offset);
> - goto skip_multiple_pages;
> - }
>
> - /* We have at least two pages to register */
> - sg_set_page(
> - &smbdirect_mr->sgl[0], pages[0], PAGE_SIZE - offset, offset);
> - i = 1;
> - while (i < num_pages - 1) {
> - sg_set_page(&smbdirect_mr->sgl[i], pages[i], PAGE_SIZE, 0);
> - i++;
> - }
> - sg_set_page(&smbdirect_mr->sgl[i], pages[i],
> - tailsz ? tailsz : PAGE_SIZE, 0);
> + log_rdma_mr(INFO, "num_pages=0x%x count=0x%zx\n",
> + num_pages, iov_iter_count(iter));
> + smbd_iter_to_mr(info, iter, smbdirect_mr->sgl, num_pages);
>
> -skip_multiple_pages:
> - dir = writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
> - smbdirect_mr->dir = dir;
> rc = ib_dma_map_sg(info->id->device, smbdirect_mr->sgl, num_pages, dir);
> if (!rc) {
> log_rdma_mr(ERR, "ib_dma_map_sg num_pages=%x dir=%x rc=%x\n",
> diff --git a/fs/cifs/smbdirect.h b/fs/cifs/smbdirect.h
> index 207ef979cd51..be2cf18b7fec 100644
> --- a/fs/cifs/smbdirect.h
> +++ b/fs/cifs/smbdirect.h
> @@ -302,8 +302,8 @@ struct smbd_mr {
>
> /* Interfaces to register and deregister MR for RDMA read/write */
> struct smbd_mr *smbd_register_mr(
> - struct smbd_connection *info, struct page *pages[], int num_pages,
> - int offset, int tailsz, bool writing, bool need_invalidate);
> + struct smbd_connection *info, struct iov_iter *iter,
> + bool writing, bool need_invalidate);
> int smbd_deregister_mr(struct smbd_mr *mr);
>
> #else
> diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
> index 83e931824bf2..7ff67a27b361 100644
> --- a/fs/cifs/transport.c
> +++ b/fs/cifs/transport.c
> @@ -270,26 +270,7 @@ smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst)
> for (i = 0; i < nvec; i++)
> buflen += iov[i].iov_len;
>
> - /*
> - * Add in the page array if there is one. The caller needs to make
> - * sure rq_offset and rq_tailsz are set correctly. If a buffer of
> - * multiple pages ends at page boundary, rq_tailsz needs to be set to
> - * PAGE_SIZE.
> - */
> - if (rqst->rq_npages) {
> - if (rqst->rq_npages == 1)
> - buflen += rqst->rq_tailsz;
> - else {
> - /*
> - * If there is more than one page, calculate the
> - * buffer length based on rq_offset and rq_tailsz
> - */
> - buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) -
> - rqst->rq_offset;
> - buflen += rqst->rq_tailsz;
> - }
> - }
> -
> + buflen += iov_iter_count(&rqst->rq_iter);
> return buflen;
> }
>
> @@ -376,23 +357,15 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
>
> total_len += sent;
>
> - /* now walk the page array and send each page in it */
> - for (i = 0; i < rqst[j].rq_npages; i++) {
> - struct bio_vec bvec;
> -
> - bvec.bv_page = rqst[j].rq_pages[i];
> - rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
> - &bvec.bv_offset);
> -
> - iov_iter_bvec(&smb_msg.msg_iter, ITER_SOURCE,
> - &bvec, 1, bvec.bv_len);
> + if (iov_iter_count(&rqst[j].rq_iter) > 0) {
> + smb_msg.msg_iter = rqst[j].rq_iter;
> rc = smb_send_kvec(server, &smb_msg, &sent);
> if (rc < 0)
> break;
> -
> total_len += sent;
> }
> - }
> +
> +}
>
> unmask:
> sigprocmask(SIG_SETMASK, &oldmask, NULL);
> @@ -1654,11 +1627,11 @@ int
> cifs_discard_remaining_data(struct TCP_Server_Info *server)
> {
> unsigned int rfclen = server->pdu_size;
> - int remaining = rfclen + HEADER_PREAMBLE_SIZE(server) -
> + size_t remaining = rfclen + HEADER_PREAMBLE_SIZE(server) -
> server->total_read;
>
> while (remaining > 0) {
> - int length;
> + ssize_t length;
>
> length = cifs_discard_from_socket(server,
> min_t(size_t, remaining,
> @@ -1804,10 +1777,15 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
> return cifs_readv_discard(server, mid);
> }
>
> - length = rdata->read_into_pages(server, rdata, data_len);
> - if (length < 0)
> - return length;
> -
> +#ifdef CONFIG_CIFS_SMB_DIRECT
> + if (rdata->mr)
> + length = data_len; /* An RDMA read is already done. */
> + else
> +#endif
> + length = cifs_read_iter_from_socket(server, &rdata->iter,
> + data_len);
> + if (length > 0)
> + rdata->got_bytes += length;
> server->total_read += length;
>
> cifs_dbg(FYI, "total_read=%u buflen=%u remaining=%u\n",
>

--
Thanks,

Steve

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