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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
This commit is contained in:
Linus Torvalds 2011-10-03 12:17:44 -07:00
parent 9b13776977 b6316429af
commit 7fd21be75d
1 changed files with 16 additions and 8 deletions
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24
fs/btrfs/file.c
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@ -1036,11 +1036,13 @@ int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
* 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 @@ static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
}
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