break;
}
- len = min((size_t)cifs_sb->wsize,
- write_size - total_written);
+ len = min(server->ops->wp_retry_size(dentry->d_inode),
+ (unsigned int)write_size - total_written);
/* iov[0] is reserved for smb header */
iov[1].iov_base = (char *)write_data + total_written;
iov[1].iov_len = len;
return rc;
}
+static struct cifs_writedata *
+wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
+ pgoff_t end, pgoff_t *index,
+ unsigned int *found_pages)
+{
+ unsigned int nr_pages;
+ struct page **pages;
+ struct cifs_writedata *wdata;
+
+ wdata = cifs_writedata_alloc((unsigned int)tofind,
+ cifs_writev_complete);
+ if (!wdata)
+ return NULL;
+
+ /*
+ * find_get_pages_tag seems to return a max of 256 on each
+ * iteration, so we must call it several times in order to
+ * fill the array or the wsize is effectively limited to
+ * 256 * PAGE_CACHE_SIZE.
+ */
+ *found_pages = 0;
+ pages = wdata->pages;
+ do {
+ nr_pages = find_get_pages_tag(mapping, index,
+ PAGECACHE_TAG_DIRTY, tofind,
+ pages);
+ *found_pages += nr_pages;
+ tofind -= nr_pages;
+ pages += nr_pages;
+ } while (nr_pages && tofind && *index <= end);
+
+ return wdata;
+}
+
+static unsigned int
+wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
+ struct address_space *mapping,
+ struct writeback_control *wbc,
+ pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
+{
+ unsigned int nr_pages = 0, i;
+ struct page *page;
+
+ for (i = 0; i < found_pages; i++) {
+ page = wdata->pages[i];
+ /*
+ * At this point we hold neither mapping->tree_lock nor
+ * lock on the page itself: the page may be truncated or
+ * invalidated (changing page->mapping to NULL), or even
+ * swizzled back from swapper_space to tmpfs file
+ * mapping
+ */
+
+ if (nr_pages == 0)
+ lock_page(page);
+ else if (!trylock_page(page))
+ break;
+
+ if (unlikely(page->mapping != mapping)) {
+ unlock_page(page);
+ break;
+ }
+
+ if (!wbc->range_cyclic && page->index > end) {
+ *done = true;
+ unlock_page(page);
+ break;
+ }
+
+ if (*next && (page->index != *next)) {
+ /* Not next consecutive page */
+ unlock_page(page);
+ break;
+ }
+
+ if (wbc->sync_mode != WB_SYNC_NONE)
+ wait_on_page_writeback(page);
+
+ if (PageWriteback(page) ||
+ !clear_page_dirty_for_io(page)) {
+ unlock_page(page);
+ break;
+ }
+
+ /*
+ * This actually clears the dirty bit in the radix tree.
+ * See cifs_writepage() for more commentary.
+ */
+ set_page_writeback(page);
+ if (page_offset(page) >= i_size_read(mapping->host)) {
+ *done = true;
+ unlock_page(page);
+ end_page_writeback(page);
+ break;
+ }
+
+ wdata->pages[i] = page;
+ *next = page->index + 1;
+ ++nr_pages;
+ }
+
+ /* reset index to refind any pages skipped */
+ if (nr_pages == 0)
+ *index = wdata->pages[0]->index + 1;
+
+ /* put any pages we aren't going to use */
+ for (i = nr_pages; i < found_pages; i++) {
+ page_cache_release(wdata->pages[i]);
+ wdata->pages[i] = NULL;
+ }
+
+ return nr_pages;
+}
+
+static int
+wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
+ struct address_space *mapping, struct writeback_control *wbc)
+{
+ int rc = 0;
+ struct TCP_Server_Info *server;
+ unsigned int i;
+
+ wdata->sync_mode = wbc->sync_mode;
+ wdata->nr_pages = nr_pages;
+ wdata->offset = page_offset(wdata->pages[0]);
+ wdata->pagesz = PAGE_CACHE_SIZE;
+ wdata->tailsz = min(i_size_read(mapping->host) -
+ page_offset(wdata->pages[nr_pages - 1]),
+ (loff_t)PAGE_CACHE_SIZE);
+ wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) + wdata->tailsz;
+
+ if (wdata->cfile != NULL)
+ cifsFileInfo_put(wdata->cfile);
+ wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
+ if (!wdata->cfile) {
+ cifs_dbg(VFS, "No writable handles for inode\n");
+ rc = -EBADF;
+ } else {
+ wdata->pid = wdata->cfile->pid;
+ server = tlink_tcon(wdata->cfile->tlink)->ses->server;
+ rc = server->ops->async_writev(wdata, cifs_writedata_release);
+ }
+
+ for (i = 0; i < nr_pages; ++i)
+ unlock_page(wdata->pages[i]);
+
+ return rc;
+}
+
static int cifs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
+ struct TCP_Server_Info *server;
bool done = false, scanned = false, range_whole = false;
pgoff_t end, index;
struct cifs_writedata *wdata;
- struct TCP_Server_Info *server;
- struct page *page;
int rc = 0;
/*
range_whole = true;
scanned = true;
}
+ server = cifs_sb_master_tcon(cifs_sb)->ses->server;
retry:
while (!done && index <= end) {
- unsigned int i, nr_pages, found_pages;
- pgoff_t next = 0, tofind;
- struct page **pages;
+ unsigned int i, nr_pages, found_pages, wsize, credits;
+ pgoff_t next = 0, tofind, saved_index = index;
+
+ rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
+ &wsize, &credits);
+ if (rc)
+ break;
- tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
- end - index) + 1;
+ tofind = min((wsize / PAGE_CACHE_SIZE) - 1, end - index) + 1;
- wdata = cifs_writedata_alloc((unsigned int)tofind,
- cifs_writev_complete);
+ wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
+ &found_pages);
if (!wdata) {
rc = -ENOMEM;
+ add_credits_and_wake_if(server, credits, 0);
break;
}
- /*
- * find_get_pages_tag seems to return a max of 256 on each
- * iteration, so we must call it several times in order to
- * fill the array or the wsize is effectively limited to
- * 256 * PAGE_CACHE_SIZE.
- */
- found_pages = 0;
- pages = wdata->pages;
- do {
- nr_pages = find_get_pages_tag(mapping, &index,
- PAGECACHE_TAG_DIRTY,
- tofind, pages);
- found_pages += nr_pages;
- tofind -= nr_pages;
- pages += nr_pages;
- } while (nr_pages && tofind && index <= end);
-
if (found_pages == 0) {
kref_put(&wdata->refcount, cifs_writedata_release);
+ add_credits_and_wake_if(server, credits, 0);
break;
}
- nr_pages = 0;
- for (i = 0; i < found_pages; i++) {
- page = wdata->pages[i];
- /*
- * At this point we hold neither mapping->tree_lock nor
- * lock on the page itself: the page may be truncated or
- * invalidated (changing page->mapping to NULL), or even
- * swizzled back from swapper_space to tmpfs file
- * mapping
- */
-
- if (nr_pages == 0)
- lock_page(page);
- else if (!trylock_page(page))
- break;
-
- if (unlikely(page->mapping != mapping)) {
- unlock_page(page);
- break;
- }
-
- if (!wbc->range_cyclic && page->index > end) {
- done = true;
- unlock_page(page);
- break;
- }
-
- if (next && (page->index != next)) {
- /* Not next consecutive page */
- unlock_page(page);
- break;
- }
-
- if (wbc->sync_mode != WB_SYNC_NONE)
- wait_on_page_writeback(page);
-
- if (PageWriteback(page) ||
- !clear_page_dirty_for_io(page)) {
- unlock_page(page);
- break;
- }
-
- /*
- * This actually clears the dirty bit in the radix tree.
- * See cifs_writepage() for more commentary.
- */
- set_page_writeback(page);
-
- if (page_offset(page) >= i_size_read(mapping->host)) {
- done = true;
- unlock_page(page);
- end_page_writeback(page);
- break;
- }
-
- wdata->pages[i] = page;
- next = page->index + 1;
- ++nr_pages;
- }
-
- /* reset index to refind any pages skipped */
- if (nr_pages == 0)
- index = wdata->pages[0]->index + 1;
-
- /* put any pages we aren't going to use */
- for (i = nr_pages; i < found_pages; i++) {
- page_cache_release(wdata->pages[i]);
- wdata->pages[i] = NULL;
- }
+ nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
+ end, &index, &next, &done);
/* nothing to write? */
if (nr_pages == 0) {
kref_put(&wdata->refcount, cifs_writedata_release);
+ add_credits_and_wake_if(server, credits, 0);
continue;
}
- wdata->sync_mode = wbc->sync_mode;
- wdata->nr_pages = nr_pages;
- wdata->offset = page_offset(wdata->pages[0]);
- wdata->pagesz = PAGE_CACHE_SIZE;
- wdata->tailsz =
- min(i_size_read(mapping->host) -
- 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)
- cifsFileInfo_put(wdata->cfile);
- wdata->cfile = find_writable_file(CIFS_I(mapping->host),
- false);
- if (!wdata->cfile) {
- cifs_dbg(VFS, "No writable handles for inode\n");
- rc = -EBADF;
- break;
- }
- wdata->pid = wdata->cfile->pid;
- server = tlink_tcon(wdata->cfile->tlink)->ses->server;
- rc = server->ops->async_writev(wdata,
- cifs_writedata_release);
- } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
+ wdata->credits = credits;
- for (i = 0; i < nr_pages; ++i)
- unlock_page(wdata->pages[i]);
+ rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
/* send failure -- clean up the mess */
if (rc != 0) {
+ add_credits_and_wake_if(server, wdata->credits, 0);
for (i = 0; i < nr_pages; ++i) {
if (rc == -EAGAIN)
redirty_page_for_writepage(wbc,
}
kref_put(&wdata->refcount, cifs_writedata_release);
+ if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
+ index = saved_index;
+ continue;
+ }
+
wbc->nr_to_write -= nr_pages;
if (wbc->nr_to_write <= 0)
done = true;
kref_put(&wdata->refcount, cifs_uncached_writedata_release);
}
-/* attempt to send write to server, retry on any -EAGAIN errors */
static int
-cifs_uncached_retry_writev(struct cifs_writedata *wdata)
+wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
+ size_t *len, unsigned long *num_pages)
{
- int rc;
- struct TCP_Server_Info *server;
+ size_t save_len, copied, bytes, cur_len = *len;
+ unsigned long i, nr_pages = *num_pages;
- server = tlink_tcon(wdata->cfile->tlink)->ses->server;
+ save_len = cur_len;
+ for (i = 0; i < nr_pages; i++) {
+ bytes = min_t(const size_t, cur_len, PAGE_SIZE);
+ copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
+ cur_len -= copied;
+ /*
+ * If we didn't copy as much as we expected, then that
+ * may mean we trod into an unmapped area. Stop copying
+ * at that point. On the next pass through the big
+ * loop, we'll likely end up getting a zero-length
+ * write and bailing out of it.
+ */
+ if (copied < bytes)
+ break;
+ }
+ cur_len = save_len - cur_len;
+ *len = cur_len;
- do {
- if (wdata->cfile->invalidHandle) {
- rc = cifs_reopen_file(wdata->cfile, false);
- if (rc != 0)
- continue;
- }
- rc = server->ops->async_writev(wdata,
- cifs_uncached_writedata_release);
- } while (rc == -EAGAIN);
+ /*
+ * If we have no data to send, then that probably means that
+ * the copy above failed altogether. That's most likely because
+ * the address in the iovec was bogus. Return -EFAULT and let
+ * the caller free anything we allocated and bail out.
+ */
+ if (!cur_len)
+ return -EFAULT;
- return rc;
+ /*
+ * i + 1 now represents the number of pages we actually used in
+ * the copy phase above.
+ */
+ *num_pages = i + 1;
+ return 0;
}
-static ssize_t
-cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset)
+static int
+cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
+ struct cifsFileInfo *open_file,
+ struct cifs_sb_info *cifs_sb, struct list_head *wdata_list)
{
- unsigned long nr_pages, i;
- size_t bytes, copied, len, cur_len;
- ssize_t total_written = 0;
- loff_t offset;
- struct cifsFileInfo *open_file;
- struct cifs_tcon *tcon;
- struct cifs_sb_info *cifs_sb;
- struct cifs_writedata *wdata, *tmp;
- struct list_head wdata_list;
- int rc;
+ int rc = 0;
+ size_t cur_len;
+ unsigned long nr_pages, num_pages, i;
+ struct cifs_writedata *wdata;
+ struct iov_iter saved_from;
+ loff_t saved_offset = offset;
pid_t pid;
-
- len = iov_iter_count(from);
- rc = generic_write_checks(file, poffset, &len, 0);
- if (rc)
- return rc;
-
- if (!len)
- return 0;
-
- iov_iter_truncate(from, len);
-
- INIT_LIST_HEAD(&wdata_list);
- cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
- open_file = file->private_data;
- tcon = tlink_tcon(open_file->tlink);
-
- if (!tcon->ses->server->ops->async_writev)
- return -ENOSYS;
-
- offset = *poffset;
+ struct TCP_Server_Info *server;
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
pid = open_file->pid;
else
pid = current->tgid;
+ server = tlink_tcon(open_file->tlink)->ses->server;
+ memcpy(&saved_from, from, sizeof(struct iov_iter));
+
do {
- size_t save_len;
+ unsigned int wsize, credits;
- nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
+ rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
+ &wsize, &credits);
+ if (rc)
+ break;
+
+ 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) {
kfree(wdata);
+ add_credits_and_wake_if(server, credits, 0);
break;
}
- save_len = cur_len;
- for (i = 0; i < nr_pages; i++) {
- bytes = min_t(size_t, cur_len, PAGE_SIZE);
- copied = copy_page_from_iter(wdata->pages[i], 0, bytes,
- from);
- cur_len -= copied;
- /*
- * If we didn't copy as much as we expected, then that
- * may mean we trod into an unmapped area. Stop copying
- * at that point. On the next pass through the big
- * loop, we'll likely end up getting a zero-length
- * write and bailing out of it.
- */
- if (copied < bytes)
- break;
- }
- cur_len = save_len - cur_len;
-
- /*
- * If we have no data to send, then that probably means that
- * the copy above failed altogether. That's most likely because
- * the address in the iovec was bogus. Set the rc to -EFAULT,
- * free anything we allocated and bail out.
- */
- if (!cur_len) {
+ 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]);
kfree(wdata);
- rc = -EFAULT;
+ add_credits_and_wake_if(server, credits, 0);
break;
}
/*
- * i + 1 now represents the number of pages we actually used in
- * the copy phase above. Bring nr_pages down to that, and free
- * any pages that we didn't use.
+ * Bring nr_pages down to the number of pages we actually used,
+ * and free any pages that we didn't use.
*/
- for ( ; nr_pages > i + 1; nr_pages--)
+ for ( ; nr_pages > num_pages; nr_pages--)
put_page(wdata->pages[nr_pages - 1]);
wdata->sync_mode = WB_SYNC_ALL;
wdata->bytes = cur_len;
wdata->pagesz = PAGE_SIZE;
wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
- rc = cifs_uncached_retry_writev(wdata);
+ wdata->credits = credits;
+
+ if (!wdata->cfile->invalidHandle ||
+ !cifs_reopen_file(wdata->cfile, false))
+ rc = server->ops->async_writev(wdata,
+ cifs_uncached_writedata_release);
if (rc) {
+ add_credits_and_wake_if(server, wdata->credits, 0);
kref_put(&wdata->refcount,
cifs_uncached_writedata_release);
+ if (rc == -EAGAIN) {
+ memcpy(from, &saved_from,
+ sizeof(struct iov_iter));
+ iov_iter_advance(from, offset - saved_offset);
+ continue;
+ }
break;
}
- list_add_tail(&wdata->list, &wdata_list);
+ list_add_tail(&wdata->list, wdata_list);
offset += cur_len;
len -= cur_len;
} while (len > 0);
+ return rc;
+}
+
+static ssize_t
+cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset)
+{
+ size_t len;
+ ssize_t total_written = 0;
+ struct cifsFileInfo *open_file;
+ struct cifs_tcon *tcon;
+ struct cifs_sb_info *cifs_sb;
+ struct cifs_writedata *wdata, *tmp;
+ struct list_head wdata_list;
+ struct iov_iter saved_from;
+ int rc;
+
+ len = iov_iter_count(from);
+ rc = generic_write_checks(file, poffset, &len, 0);
+ if (rc)
+ return rc;
+
+ if (!len)
+ return 0;
+
+ iov_iter_truncate(from, len);
+
+ INIT_LIST_HEAD(&wdata_list);
+ cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
+ open_file = file->private_data;
+ tcon = tlink_tcon(open_file->tlink);
+
+ if (!tcon->ses->server->ops->async_writev)
+ return -ENOSYS;
+
+ memcpy(&saved_from, from, sizeof(struct iov_iter));
+
+ rc = cifs_write_from_iter(*poffset, len, from, open_file, cifs_sb,
+ &wdata_list);
+
/*
* If at least one write was successfully sent, then discard any rc
* value from the later writes. If the other write succeeds, then
/* resend call if it's a retryable error */
if (rc == -EAGAIN) {
- rc = cifs_uncached_retry_writev(wdata);
+ struct list_head tmp_list;
+ struct iov_iter tmp_from;
+
+ INIT_LIST_HEAD(&tmp_list);
+ list_del_init(&wdata->list);
+
+ memcpy(&tmp_from, &saved_from,
+ sizeof(struct iov_iter));
+ iov_iter_advance(&tmp_from,
+ wdata->offset - *poffset);
+
+ rc = cifs_write_from_iter(wdata->offset,
+ wdata->bytes, &tmp_from,
+ open_file, cifs_sb, &tmp_list);
+
+ list_splice(&tmp_list, &wdata_list);
+
+ kref_put(&wdata->refcount,
+ cifs_uncached_writedata_release);
goto restart_loop;
}
}
cifs_readdata_release(refcount);
}
-static int
-cifs_retry_async_readv(struct cifs_readdata *rdata)
-{
- int rc;
- struct TCP_Server_Info *server;
-
- server = tlink_tcon(rdata->cfile->tlink)->ses->server;
-
- do {
- if (rdata->cfile->invalidHandle) {
- rc = cifs_reopen_file(rdata->cfile, true);
- if (rc != 0)
- continue;
- }
- rc = server->ops->async_readv(rdata);
- } while (rc == -EAGAIN);
-
- return rc;
-}
-
/**
* cifs_readdata_to_iov - copy data from pages in response to an iovec
* @rdata: the readdata response with list of pages holding data
total_read += result;
}
- return total_read > 0 ? total_read : result;
+ return total_read > 0 && result != -EAGAIN ? total_read : result;
}
-ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
+static int
+cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
+ struct cifs_sb_info *cifs_sb, struct list_head *rdata_list)
{
- struct file *file = iocb->ki_filp;
- ssize_t rc;
- size_t len, cur_len;
- ssize_t total_read = 0;
- loff_t offset = iocb->ki_pos;
+ struct cifs_readdata *rdata;
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;
+ size_t cur_len;
+ int rc;
pid_t pid;
+ struct TCP_Server_Info *server;
- len = iov_iter_count(to);
- if (!len)
- return 0;
-
- INIT_LIST_HEAD(&rdata_list);
- cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
- open_file = file->private_data;
- tcon = tlink_tcon(open_file->tlink);
-
- if (!tcon->ses->server->ops->async_readv)
- return -ENOSYS;
+ server = tlink_tcon(open_file->tlink)->ses->server;
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
pid = open_file->pid;
else
pid = current->tgid;
- if ((file->f_flags & O_ACCMODE) == O_WRONLY)
- cifs_dbg(FYI, "attempting read on write only file instance\n");
-
do {
- cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
+ cur_len = min_t(const size_t, len, cifs_sb->rsize);
npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
/* allocate a readdata struct */
rdata->pagesz = PAGE_SIZE;
rdata->read_into_pages = cifs_uncached_read_into_pages;
- rc = cifs_retry_async_readv(rdata);
+ if (!rdata->cfile->invalidHandle ||
+ !cifs_reopen_file(rdata->cfile, true))
+ rc = server->ops->async_readv(rdata);
error:
if (rc) {
kref_put(&rdata->refcount,
cifs_uncached_readdata_release);
+ if (rc == -EAGAIN)
+ continue;
break;
}
- list_add_tail(&rdata->list, &rdata_list);
+ list_add_tail(&rdata->list, rdata_list);
offset += cur_len;
len -= cur_len;
} while (len > 0);
+ return rc;
+}
+
+ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct file *file = iocb->ki_filp;
+ ssize_t rc;
+ size_t len;
+ ssize_t total_read = 0;
+ loff_t offset = iocb->ki_pos;
+ struct cifs_sb_info *cifs_sb;
+ struct cifs_tcon *tcon;
+ struct cifsFileInfo *open_file;
+ struct cifs_readdata *rdata, *tmp;
+ struct list_head rdata_list;
+
+ len = iov_iter_count(to);
+ if (!len)
+ return 0;
+
+ INIT_LIST_HEAD(&rdata_list);
+ cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
+ open_file = file->private_data;
+ tcon = tlink_tcon(open_file->tlink);
+
+ if (!tcon->ses->server->ops->async_readv)
+ return -ENOSYS;
+
+ if ((file->f_flags & O_ACCMODE) == O_WRONLY)
+ cifs_dbg(FYI, "attempting read on write only file instance\n");
+
+ rc = cifs_send_async_read(offset, len, open_file, cifs_sb, &rdata_list);
+
/* if at least one read request send succeeded, then reset rc */
if (!list_empty(&rdata_list))
rc = 0;
len = iov_iter_count(to);
/* the loop below should proceed in the order of increasing offsets */
+again:
list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
- again:
if (!rc) {
/* FIXME: freezable sleep too? */
rc = wait_for_completion_killable(&rdata->done);
rc = rdata->result;
/* resend call if it's a retryable error */
if (rc == -EAGAIN) {
- rc = cifs_retry_async_readv(rdata);
+ struct list_head tmp_list;
+
+ list_del_init(&rdata->list);
+ INIT_LIST_HEAD(&tmp_list);
+
+ rc = cifs_send_async_read(rdata->offset,
+ rdata->bytes, rdata->cfile,
+ cifs_sb, &tmp_list);
+
+ list_splice(&tmp_list, &rdata_list);
+
+ kref_put(&rdata->refcount,
+ cifs_uncached_readdata_release);
goto again;
}
} else {
total_read += result;
}
- return total_read > 0 ? total_read : result;
+ return total_read > 0 && result != -EAGAIN ? total_read : result;
+}
+
+static int
+readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
+ unsigned int rsize, struct list_head *tmplist,
+ unsigned int *nr_pages, loff_t *offset, unsigned int *bytes)
+{
+ struct page *page, *tpage;
+ unsigned int expected_index;
+ int rc;
+
+ INIT_LIST_HEAD(tmplist);
+
+ page = list_entry(page_list->prev, struct page, lru);
+
+ /*
+ * Lock the page and put it in the cache. Since no one else
+ * should have access to this page, we're safe to simply set
+ * PG_locked without checking it first.
+ */
+ __set_page_locked(page);
+ rc = add_to_page_cache_locked(page, mapping,
+ page->index, GFP_KERNEL);
+
+ /* give up if we can't stick it in the cache */
+ if (rc) {
+ __clear_page_locked(page);
+ return rc;
+ }
+
+ /* move first page to the tmplist */
+ *offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
+ *bytes = PAGE_CACHE_SIZE;
+ *nr_pages = 1;
+ list_move_tail(&page->lru, tmplist);
+
+ /* now try and add more pages onto the request */
+ expected_index = page->index + 1;
+ list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
+ /* discontinuity ? */
+ if (page->index != expected_index)
+ break;
+
+ /* would this page push the read over the rsize? */
+ if (*bytes + PAGE_CACHE_SIZE > rsize)
+ break;
+
+ __set_page_locked(page);
+ if (add_to_page_cache_locked(page, mapping, page->index,
+ GFP_KERNEL)) {
+ __clear_page_locked(page);
+ break;
+ }
+ list_move_tail(&page->lru, tmplist);
+ (*bytes) += PAGE_CACHE_SIZE;
+ expected_index++;
+ (*nr_pages)++;
+ }
+ return rc;
}
static int cifs_readpages(struct file *file, struct address_space *mapping,
struct list_head tmplist;
struct cifsFileInfo *open_file = file->private_data;
struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
- unsigned int rsize = cifs_sb->rsize;
+ struct TCP_Server_Info *server;
pid_t pid;
- /*
- * Give up immediately if rsize is too small to read an entire page.
- * The VFS will fall back to readpage. We should never reach this
- * point however since we set ra_pages to 0 when the rsize is smaller
- * than a cache page.
- */
- if (unlikely(rsize < PAGE_CACHE_SIZE))
- return 0;
-
/*
* Reads as many pages as possible from fscache. Returns -ENOBUFS
* immediately if the cookie is negative
pid = current->tgid;
rc = 0;
- INIT_LIST_HEAD(&tmplist);
+ server = tlink_tcon(open_file->tlink)->ses->server;
cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
__func__, file, mapping, num_pages);
* the rdata->pages, then we want them in increasing order.
*/
while (!list_empty(page_list)) {
- unsigned int i;
- unsigned int bytes = PAGE_CACHE_SIZE;
- unsigned int expected_index;
- unsigned int nr_pages = 1;
+ unsigned int i, nr_pages, bytes;
loff_t offset;
struct page *page, *tpage;
struct cifs_readdata *rdata;
- page = list_entry(page_list->prev, struct page, lru);
-
/*
- * Lock the page and put it in the cache. Since no one else
- * should have access to this page, we're safe to simply set
- * PG_locked without checking it first.
+ * Give up immediately if rsize is too small to read an entire
+ * page. The VFS will fall back to readpage. We should never
+ * reach this point however since we set ra_pages to 0 when the
+ * rsize is smaller than a cache page.
*/
- __set_page_locked(page);
- rc = add_to_page_cache_locked(page, mapping,
- page->index, GFP_KERNEL);
+ if (unlikely(cifs_sb->rsize < PAGE_CACHE_SIZE))
+ return 0;
- /* give up if we can't stick it in the cache */
- if (rc) {
- __clear_page_locked(page);
+ rc = readpages_get_pages(mapping, page_list, cifs_sb->rsize,
+ &tmplist, &nr_pages, &offset, &bytes);
+ if (rc)
break;
- }
-
- /* move first page to the tmplist */
- offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
- list_move_tail(&page->lru, &tmplist);
-
- /* now try and add more pages onto the request */
- expected_index = page->index + 1;
- list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
- /* discontinuity ? */
- if (page->index != expected_index)
- break;
-
- /* would this page push the read over the rsize? */
- if (bytes + PAGE_CACHE_SIZE > rsize)
- break;
-
- __set_page_locked(page);
- if (add_to_page_cache_locked(page, mapping,
- page->index, GFP_KERNEL)) {
- __clear_page_locked(page);
- break;
- }
- list_move_tail(&page->lru, &tmplist);
- bytes += PAGE_CACHE_SIZE;
- expected_index++;
- nr_pages++;
- }
rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
if (!rdata) {
rdata->pages[rdata->nr_pages++] = page;
}
- rc = cifs_retry_async_readv(rdata);
- if (rc != 0) {
+ if (!rdata->cfile->invalidHandle ||
+ !cifs_reopen_file(rdata->cfile, true))
+ rc = server->ops->async_readv(rdata);
+ if (rc) {
for (i = 0; i < rdata->nr_pages; i++) {
page = rdata->pages[i];
lru_cache_add_file(page);
unlock_page(page);
page_cache_release(page);
+ if (rc == -EAGAIN)
+ list_add_tail(&page->lru, &tmplist);
}
kref_put(&rdata->refcount, cifs_readdata_release);
+ if (rc == -EAGAIN) {
+ /* Re-add pages to the page_list and retry */
+ list_splice(&tmplist, page_list);
+ continue;
+ }
break;
}
projects / firefly-linux-kernel-4.4.55.git / blobdiff