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authorBoaz Harrosh <bharrosh@panasas.com>2012-06-08 02:02:30 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-08-09 08:31:40 -0700
commita647f0df62cc4eaa0f42b85c71843ed90e150536 (patch)
treea628b80623747017698a8020e9066f86adf66905 /fs/nfs
parente73b09d8f258df200adb6383c77c38c31f6f4baa (diff)
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pnfs-obj: Fix __r4w_get_page when offset is beyond i_size
commit c999ff68029ebd0f56ccae75444f640f6d5a27d2 upstream. It is very common for the end of the file to be unaligned on stripe size. But since we know it's beyond file's end then the XOR should be preformed with all zeros. Old code used to just read zeros out of the OSD devices, which is a great waist. But what scares me more about this situation is that, we now have pages attached to the file's mapping that are beyond i_size. I don't like the kind of bugs this calls for. Fix both birds, by returning a global zero_page, if offset is beyond i_size. TODO: Change the API to ->__r4w_get_page() so a NULL can be returned without being considered as error, since XOR API treats NULL entries as zero_pages. [Bug since 3.2. Should apply the same way to all Kernels since] Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> [bwh: Backported to 3.2: adjust for lack of wdata->header] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/objlayout/objio_osd.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
index 42ac1bf6fcc..1afe74c42c8 100644
--- a/fs/nfs/objlayout/objio_osd.c
+++ b/fs/nfs/objlayout/objio_osd.c
@@ -487,8 +487,16 @@ static struct page *__r4w_get_page(void *priv, u64 offset, bool *uptodate)
struct objio_state *objios = priv;
struct nfs_write_data *wdata = objios->oir.rpcdata;
pgoff_t index = offset / PAGE_SIZE;
- struct page *page = find_get_page(wdata->inode->i_mapping, index);
+ struct page *page;
+ loff_t i_size = i_size_read(wdata->inode);
+ if (offset >= i_size) {
+ *uptodate = true;
+ dprintk("%s: g_zero_page index=0x%lx\n", __func__, index);
+ return ZERO_PAGE(0);
+ }
+
+ page = find_get_page(wdata->inode->i_mapping, index);
if (!page) {
page = find_or_create_page(wdata->inode->i_mapping,
index, GFP_NOFS);
@@ -509,8 +517,10 @@ static struct page *__r4w_get_page(void *priv, u64 offset, bool *uptodate)
static void __r4w_put_page(void *priv, struct page *page)
{
- dprintk("%s: index=0x%lx\n", __func__, page->index);
- page_cache_release(page);
+ dprintk("%s: index=0x%lx\n", __func__,
+ (page == ZERO_PAGE(0)) ? -1UL : page->index);
+ if (ZERO_PAGE(0) != page)
+ page_cache_release(page);
return;
}