Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux.git] / fs / cifs / file.c
index 216d7e99f9219317bd0f2567c898925df77ec68d..8807442c94dd3323cbb7f9f8283c4f1c1a2d1480 100644 (file)
@@ -2579,19 +2579,32 @@ cifs_writev(struct kiocb *iocb, const struct iovec *iov,
        struct cifsInodeInfo *cinode = CIFS_I(inode);
        struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
        ssize_t rc = -EACCES;
-       loff_t lock_pos = pos;
+       loff_t lock_pos = iocb->ki_pos;
 
-       if (file->f_flags & O_APPEND)
-               lock_pos = i_size_read(inode);
        /*
         * We need to hold the sem to be sure nobody modifies lock list
         * with a brlock that prevents writing.
         */
        down_read(&cinode->lock_sem);
+       mutex_lock(&inode->i_mutex);
+       if (file->f_flags & O_APPEND)
+               lock_pos = i_size_read(inode);
        if (!cifs_find_lock_conflict(cfile, lock_pos, iov_length(iov, nr_segs),
                                     server->vals->exclusive_lock_type, NULL,
-                                    CIFS_WRITE_OP))
-               rc = generic_file_aio_write(iocb, iov, nr_segs, pos);
+                                    CIFS_WRITE_OP)) {
+               rc = __generic_file_aio_write(iocb, iov, nr_segs);
+               mutex_unlock(&inode->i_mutex);
+
+               if (rc > 0) {
+                       ssize_t err;
+
+                       err = generic_write_sync(file, iocb->ki_pos - rc, rc);
+                       if (rc < 0)
+                               rc = err;
+               }
+       } else {
+               mutex_unlock(&inode->i_mutex);
+       }
        up_read(&cinode->lock_sem);
        return rc;
 }
@@ -2727,56 +2740,27 @@ cifs_retry_async_readv(struct cifs_readdata *rdata)
 /**
  * cifs_readdata_to_iov - copy data from pages in response to an iovec
  * @rdata:     the readdata response with list of pages holding data
- * @iov:       vector in which we should copy the data
- * @nr_segs:   number of segments in vector
- * @offset:    offset into file of the first iovec
- * @copied:    used to return the amount of data copied to the iov
+ * @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 ssize_t
-cifs_readdata_to_iov(struct cifs_readdata *rdata, const struct iovec *iov,
-                       unsigned long nr_segs, loff_t offset, ssize_t *copied)
+static int
+cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
 {
-       int rc = 0;
-       struct iov_iter ii;
-       size_t pos = rdata->offset - offset;
-       ssize_t remaining = rdata->bytes;
-       unsigned char *pdata;
+       size_t remaining = rdata->bytes;
        unsigned int i;
 
-       /* set up iov_iter and advance to the correct offset */
-       iov_iter_init(&ii, iov, nr_segs, iov_length(iov, nr_segs), 0);
-       iov_iter_advance(&ii, pos);
-
-       *copied = 0;
        for (i = 0; i < rdata->nr_pages; i++) {
-               ssize_t copy;
                struct page *page = rdata->pages[i];
-
-               /* copy a whole page or whatever's left */
-               copy = min_t(ssize_t, remaining, PAGE_SIZE);
-
-               /* ...but limit it to whatever space is left in the iov */
-               copy = min_t(ssize_t, copy, iov_iter_count(&ii));
-
-               /* go while there's data to be copied and no errors */
-               if (copy && !rc) {
-                       pdata = kmap(page);
-                       rc = memcpy_toiovecend(ii.iov, pdata, ii.iov_offset,
-                                               (int)copy);
-                       kunmap(page);
-                       if (!rc) {
-                               *copied += copy;
-                               remaining -= copy;
-                               iov_iter_advance(&ii, copy);
-                       }
-               }
+               size_t copy = min(remaining, PAGE_SIZE);
+               size_t written = copy_page_to_iter(page, 0, copy, iter);
+               remaining -= written;
+               if (written < copy && iov_iter_count(iter) > 0)
+                       break;
        }
-
-       return rc;
+       return remaining ? -EFAULT : 0;
 }
 
 static void
@@ -2837,20 +2821,21 @@ cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
        return total_read > 0 ? total_read : result;
 }
 
-static ssize_t
-cifs_iovec_read(struct file *file, const struct iovec *iov,
-                unsigned long nr_segs, loff_t *poffset)
+ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
+                              unsigned long nr_segs, loff_t pos)
 {
+       struct file *file = iocb->ki_filp;
        ssize_t rc;
        size_t len, cur_len;
        ssize_t total_read = 0;
-       loff_t offset = *poffset;
+       loff_t offset = pos;
        unsigned int npages;
        struct cifs_sb_info *cifs_sb;
        struct cifs_tcon *tcon;
        struct cifsFileInfo *open_file;
        struct cifs_readdata *rdata, *tmp;
        struct list_head rdata_list;
+       struct iov_iter to;
        pid_t pid;
 
        if (!nr_segs)
@@ -2860,6 +2845,8 @@ cifs_iovec_read(struct file *file, const struct iovec *iov,
        if (!len)
                return 0;
 
+       iov_iter_init(&to, iov, nr_segs, len, 0);
+
        INIT_LIST_HEAD(&rdata_list);
        cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
        open_file = file->private_data;
@@ -2917,55 +2904,44 @@ error:
        if (!list_empty(&rdata_list))
                rc = 0;
 
+       len = iov_iter_count(&to);
        /* the loop below should proceed in the order of increasing offsets */
-restart_loop:
        list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
+       again:
                if (!rc) {
-                       ssize_t copied;
-
                        /* FIXME: freezable sleep too? */
                        rc = wait_for_completion_killable(&rdata->done);
                        if (rc)
                                rc = -EINTR;
-                       else if (rdata->result)
+                       else if (rdata->result) {
                                rc = rdata->result;
-                       else {
-                               rc = cifs_readdata_to_iov(rdata, iov,
-                                                       nr_segs, *poffset,
-                                                       &copied);
-                               total_read += copied;
+                               /* resend call if it's a retryable error */
+                               if (rc == -EAGAIN) {
+                                       rc = cifs_retry_async_readv(rdata);
+                                       goto again;
+                               }
+                       } else {
+                               rc = cifs_readdata_to_iov(rdata, &to);
                        }
 
-                       /* resend call if it's a retryable error */
-                       if (rc == -EAGAIN) {
-                               rc = cifs_retry_async_readv(rdata);
-                               goto restart_loop;
-                       }
                }
                list_del_init(&rdata->list);
                kref_put(&rdata->refcount, cifs_uncached_readdata_release);
        }
 
+       total_read = len - iov_iter_count(&to);
+
        cifs_stats_bytes_read(tcon, total_read);
-       *poffset += total_read;
 
        /* mask nodata case */
        if (rc == -ENODATA)
                rc = 0;
 
-       return total_read ? total_read : rc;
-}
-
-ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
-                              unsigned long nr_segs, loff_t pos)
-{
-       ssize_t read;
-
-       read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos);
-       if (read > 0)
-               iocb->ki_pos = pos;
-
-       return read;
+       if (total_read) {
+               iocb->ki_pos = pos + total_read;
+               return total_read;
+       }
+       return rc;
 }
 
 ssize_t