cifs: convert async write code to pass in data via rq_pages array

Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

4 files changed, 33 insertions, 95 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index a81790005e57..cc70ac0bac47 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -999,8 +999,8 @@ struct cifs_writedata {
         pid_t                           pid;
         unsigned int                    bytes;
         int                             result;
-        void (*marshal_iov) (struct kvec *iov,
-                             struct cifs_writedata *wdata);
+        unsigned int                    pagesz;
+        unsigned int                    tailsz;
         unsigned int                    nr_pages;
         struct page                     *pages[1];
 };
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 2f86c84468cb..a110e0784221 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2033,11 +2033,11 @@ cifs_writev_callback(struct mid_q_entry *mid)
 int
 cifs_async_writev(struct cifs_writedata *wdata)
 {
-        int i, rc = -EACCES;
+        int rc = -EACCES;
         WRITE_REQ *smb = NULL;
         int wct;
         struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
-        struct kvec *iov = NULL;
+        struct kvec iov;
         struct smb_rqst rqst = { };
 
         if (tcon->ses->capabilities & CAP_LARGE_FILES) {
@@ -2054,15 +2054,6 @@ cifs_async_writev(struct cifs_writedata *wdata)
         if (rc)
                 goto async_writev_out;
 
-        /* 1 iov per page + 1 for header */
-        rqst.rq_nvec = wdata->nr_pages + 1;
-        iov = kzalloc((rqst.rq_nvec) * sizeof(*iov), GFP_NOFS);
-        if (iov == NULL) {
-                rc = -ENOMEM;
-                goto async_writev_out;
-        }
-        rqst.rq_iov = iov;
-
         smb->hdr.Pid = cpu_to_le16((__u16)wdata->pid);
         smb->hdr.PidHigh = cpu_to_le16((__u16)(wdata->pid >> 16));
 
@@ -2079,18 +2070,15 @@ cifs_async_writev(struct cifs_writedata *wdata)
             cpu_to_le16(offsetof(struct smb_com_write_req, Data) - 4);
 
         /* 4 for RFC1001 length + 1 for BCC */
-        iov[0].iov_len = be32_to_cpu(smb->hdr.smb_buf_length) + 4 + 1;
-        iov[0].iov_base = smb;
+        iov.iov_len = be32_to_cpu(smb->hdr.smb_buf_length) + 4 + 1;
+        iov.iov_base = smb;
 
-        /*
-         * This function should marshal up the page array into the kvec
-         * array, reserving [0] for the header. It should kmap the pages
-         * and set the iov_len properly for each one. It may also set
-         * wdata->bytes too.
-         */
-        cifs_kmap_lock();
-        wdata->marshal_iov(iov, wdata);
-        cifs_kmap_unlock();
+        rqst.rq_iov = &iov;
+        rqst.rq_nvec = 1;
+        rqst.rq_pages = wdata->pages;
+        rqst.rq_npages = wdata->nr_pages;
+        rqst.rq_pagesz = wdata->pagesz;
+        rqst.rq_tailsz = wdata->tailsz;
 
         cFYI(1, "async write at %llu %u bytes", wdata->offset, wdata->bytes);
 
@@ -2106,7 +2094,7 @@ cifs_async_writev(struct cifs_writedata *wdata)
                                 (struct smb_com_writex_req *)smb;
                 inc_rfc1001_len(&smbw->hdr, wdata->bytes + 5);
                 put_bcc(wdata->bytes + 5, &smbw->hdr);
-                iov[0].iov_len += 4; /* pad bigger by four bytes */
+                iov.iov_len += 4; /* pad bigger by four bytes */
         }
 
         kref_get(&wdata->refcount);
@@ -2118,13 +2106,8 @@ cifs_async_writev(struct cifs_writedata *wdata)
         else
                 kref_put(&wdata->refcount, cifs_writedata_release);
 
-        /* send is done, unmap pages */
-        for (i = 0; i < wdata->nr_pages; i++)
-                kunmap(wdata->pages[i]);
-
 async_writev_out:
         cifs_small_buf_release(smb);
-        kfree(iov);
         return rc;
 }
 
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 2418618118b6..8a781226ae33 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1738,27 +1738,6 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
         return rc;
 }
 
-/*
- * Marshal up the iov array, reserving the first one for the header. Also,
- * set wdata->bytes.
- */
-static void
-cifs_writepages_marshal_iov(struct kvec *iov, struct cifs_writedata *wdata)
-{
-        int i;
-        struct inode *inode = wdata->cfile->dentry->d_inode;
-        loff_t size = i_size_read(inode);
-
-        /* marshal up the pages into iov array */
-        wdata->bytes = 0;
-        for (i = 0; i < wdata->nr_pages; i++) {
-                iov[i + 1].iov_len = min(size - page_offset(wdata->pages[i]),
-                                        (loff_t)PAGE_CACHE_SIZE);
-                iov[i + 1].iov_base = kmap(wdata->pages[i]);
-                wdata->bytes += iov[i + 1].iov_len;
-        }
-}
-
 static int cifs_writepages(struct address_space *mapping,
                            struct writeback_control *wbc)
 {
@@ -1769,6 +1748,7 @@ static int cifs_writepages(struct address_space *mapping,
         struct TCP_Server_Info *server;
         struct page *page;
         int rc = 0;
+        loff_t isize = i_size_read(mapping->host);
 
         /*
          * If wsize is smaller than the page cache size, default to writing
@@ -1873,7 +1853,7 @@ retry:
                          */
                         set_page_writeback(page);
 
-                        if (page_offset(page) >= mapping->host->i_size) {
+                        if (page_offset(page) >= isize) {
                                 done = true;
                                 unlock_page(page);
                                 end_page_writeback(page);
@@ -1904,7 +1884,12 @@ retry:
                 wdata->sync_mode = wbc->sync_mode;
                 wdata->nr_pages = nr_pages;
                 wdata->offset = page_offset(wdata->pages[0]);
-                wdata->marshal_iov = cifs_writepages_marshal_iov;
+                wdata->pagesz = PAGE_CACHE_SIZE;
+                wdata->tailsz =
+                        min(isize - page_offset(wdata->pages[nr_pages - 1]),
+                            (loff_t)PAGE_CACHE_SIZE);
+                wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) +
+                                        wdata->tailsz;
 
                 do {
                         if (wdata->cfile != NULL)
@@ -2206,20 +2191,6 @@ size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
 }
 
 static void
-cifs_uncached_marshal_iov(struct kvec *iov, struct cifs_writedata *wdata)
-{
-        int i;
-        size_t bytes = wdata->bytes;
-
-        /* marshal up the pages into iov array */
-        for (i = 0; i < wdata->nr_pages; i++) {
-                iov[i + 1].iov_len = min_t(size_t, bytes, PAGE_SIZE);
-                iov[i + 1].iov_base = kmap(wdata->pages[i]);
-                bytes -= iov[i + 1].iov_len;
-        }
-}
-
-static void
 cifs_uncached_writev_complete(struct work_struct *work)
 {
         int i;
@@ -2339,7 +2310,8 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
                 wdata->cfile = cifsFileInfo_get(open_file);
                 wdata->pid = pid;
                 wdata->bytes = cur_len;
-                wdata->marshal_iov = cifs_uncached_marshal_iov;
+                wdata->pagesz = PAGE_SIZE;
+                wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
                 rc = cifs_uncached_retry_writev(wdata);
                 if (rc) {
                         kref_put(&wdata->refcount, cifs_writedata_release);
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index a04301b69b4e..68023d23702b 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1484,25 +1484,16 @@ smb2_writev_callback(struct mid_q_entry *mid)
 int
 smb2_async_writev(struct cifs_writedata *wdata)
 {
-        int i, rc = -EACCES;
+        int rc = -EACCES;
         struct smb2_write_req *req = NULL;
         struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
-        struct kvec *iov = NULL;
+        struct kvec iov;
         struct smb_rqst rqst;
 
         rc = small_smb2_init(SMB2_WRITE, tcon, (void **) &req);
         if (rc)
                 goto async_writev_out;
 
-        /* 1 iov per page + 1 for header */
-        iov = kzalloc((wdata->nr_pages + 1) * sizeof(*iov), GFP_NOFS);
-        if (iov == NULL) {
-                rc = -ENOMEM;
-                goto async_writev_out;
-        }
-        rqst.rq_iov = iov;
-        rqst.rq_nvec = wdata->nr_pages + 1;
-
         req->hdr.ProcessId = cpu_to_le32(wdata->cfile->pid);
 
         req->PersistentFileId = wdata->cfile->fid.persistent_fid;
@@ -1517,18 +1508,15 @@ smb2_async_writev(struct cifs_writedata *wdata)
         req->RemainingBytes = 0;
 
         /* 4 for rfc1002 length field and 1 for Buffer */
-        iov[0].iov_len = get_rfc1002_length(req) + 4 - 1;
-        iov[0].iov_base = (char *)req;
+        iov.iov_len = get_rfc1002_length(req) + 4 - 1;
+        iov.iov_base = req;
 
-        /*
-         * This function should marshal up the page array into the kvec
-         * array, reserving [0] for the header. It should kmap the pages
-         * and set the iov_len properly for each one. It may also set
-         * wdata->bytes too.
-         */
-        cifs_kmap_lock();
-        wdata->marshal_iov(iov, wdata);
-        cifs_kmap_unlock();
+        rqst.rq_iov = &iov;
+        rqst.rq_nvec = 1;
+        rqst.rq_pages = wdata->pages;
+        rqst.rq_npages = wdata->nr_pages;
+        rqst.rq_pagesz = wdata->pagesz;
+        rqst.rq_tailsz = wdata->tailsz;
 
         cFYI(1, "async write at %llu %u bytes", wdata->offset, wdata->bytes);
 
@@ -1543,13 +1531,8 @@ smb2_async_writev(struct cifs_writedata *wdata)
         if (rc)
                 kref_put(&wdata->refcount, cifs_writedata_release);
 
-        /* send is done, unmap pages */
-        for (i = 0; i < wdata->nr_pages; i++)
-                kunmap(wdata->pages[i]);
-
 async_writev_out:
         cifs_small_buf_release(req);
-        kfree(iov);
         return rc;
 }