提交 69cebd75 编写于 作者: P Pavel Shilovsky 提交者: Steve French

CIFS: Fix rsize usage in readpages

If a server changes maximum buffer size for read (rsize) requests
on reconnect we can fail on repeating with a big size buffer on
-EAGAIN error in readpages. Fix this by checking rsize all the
time before repeating requests.
Reviewed-by: NShirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>
上级 387eb92a
......@@ -3349,6 +3349,8 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
unsigned int expected_index;
int rc;
INIT_LIST_HEAD(tmplist);
page = list_entry(page_list->prev, struct page, lru);
/*
......@@ -3404,18 +3406,9 @@ 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
......@@ -3434,7 +3427,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
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);
......@@ -3456,8 +3449,17 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
struct page *page, *tpage;
struct cifs_readdata *rdata;
rc = readpages_get_pages(mapping, page_list, rsize, &tmplist,
&nr_pages, &offset, &bytes);
/*
* 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(cifs_sb->rsize < PAGE_CACHE_SIZE))
return 0;
rc = readpages_get_pages(mapping, page_list, cifs_sb->rsize,
&tmplist, &nr_pages, &offset, &bytes);
if (rc)
break;
......@@ -3487,15 +3489,24 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
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;
}
......
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