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authorLinus Torvalds <torvalds@linux-foundation.org>2011-10-03 23:17:44 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2011-10-03 23:17:44 +0400
commit7fd21be75dce605e7cf273bd64b6d733d422fb04 (patch)
tree4a75560e71e10fb773d4ed367bcf0dd23be147c8
parent9b13776977d45505469edc6decc93e9e3799afe2 (diff)
parentb6316429af7f365f307dfd2b6a7a42f2563aef19 (diff)
downloadlinux-7fd21be75dce605e7cf273bd64b6d733d422fb04.tar.xz
Merge branch 'btrfs-3.0' of git://github.com/chrismason/linux
* 'btrfs-3.0' of git://github.com/chrismason/linux: Btrfs: force a page fault if we have a shorty copy on a page boundary
-rw-r--r--fs/btrfs/file.c24
1 files changed, 16 insertions, 8 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index a381cd22f518..e4e57d59edb7 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1036,11 +1036,13 @@ out:
* on error we return an unlocked page and the error value
* on success we return a locked page and 0
*/
-static int prepare_uptodate_page(struct page *page, u64 pos)
+static int prepare_uptodate_page(struct page *page, u64 pos,
+ bool force_uptodate)
{
int ret = 0;
- if ((pos & (PAGE_CACHE_SIZE - 1)) && !PageUptodate(page)) {
+ if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) &&
+ !PageUptodate(page)) {
ret = btrfs_readpage(NULL, page);
if (ret)
return ret;
@@ -1061,7 +1063,7 @@ static int prepare_uptodate_page(struct page *page, u64 pos)
static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
struct page **pages, size_t num_pages,
loff_t pos, unsigned long first_index,
- size_t write_bytes)
+ size_t write_bytes, bool force_uptodate)
{
struct extent_state *cached_state = NULL;
int i;
@@ -1086,10 +1088,11 @@ again:
}
if (i == 0)
- err = prepare_uptodate_page(pages[i], pos);
+ err = prepare_uptodate_page(pages[i], pos,
+ force_uptodate);
if (i == num_pages - 1)
err = prepare_uptodate_page(pages[i],
- pos + write_bytes);
+ pos + write_bytes, false);
if (err) {
page_cache_release(pages[i]);
faili = i - 1;
@@ -1158,6 +1161,7 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
size_t num_written = 0;
int nrptrs;
int ret = 0;
+ bool force_page_uptodate = false;
nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
@@ -1200,7 +1204,8 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
* contents of pages from loop to loop
*/
ret = prepare_pages(root, file, pages, num_pages,
- pos, first_index, write_bytes);
+ pos, first_index, write_bytes,
+ force_page_uptodate);
if (ret) {
btrfs_delalloc_release_space(inode,
num_pages << PAGE_CACHE_SHIFT);
@@ -1217,12 +1222,15 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
if (copied < write_bytes)
nrptrs = 1;
- if (copied == 0)
+ if (copied == 0) {
+ force_page_uptodate = true;
dirty_pages = 0;
- else
+ } else {
+ force_page_uptodate = false;
dirty_pages = (copied + offset +
PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT;
+ }
/*
* If we had a short copy we need to release the excess delaloc