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mm: make read_cache_page synchronous

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Ensure pages are uptodate after returning from read_cache_page, which allows
us to cut out most of the filesystem-internal PageUptodate calls.

I didn't have a great look down the call chains, but this appears to fixes 7
possible use-before uptodate in hfs, 2 in hfsplus, 1 in jfs, a few in
ecryptfs, 1 in jffs2, and a possible cleared data overwritten with readpage in
block2mtd.  All depending on whether the filler is async and/or can return
with a !uptodate page.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Nick Piggin
2007-05-06 14:49:04 -07:00
committed by Linus Torvalds
parent 714b8171af
commit 6fe6900e1e
24 changed files with 71 additions and 146 deletions
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30
fs/ntfs/super.c
View File

@@ -2471,7 +2471,6 @@ static s64 get_nr_free_clusters(ntfs_volume *vol)
s64 nr_free = vol->nr_clusters;
u32 *kaddr;
struct address_space *mapping = vol->lcnbmp_ino->i_mapping;
filler_t *readpage = (filler_t*)mapping->a_ops->readpage;
struct page *page;
pgoff_t index, max_index;
@@ -2494,24 +2493,14 @@ static s64 get_nr_free_clusters(ntfs_volume *vol)
* Read the page from page cache, getting it from backing store
* if necessary, and increment the use count.
*/
page = read_cache_page(mapping, index, (filler_t*)readpage,
NULL);
page = read_mapping_page(mapping, index, NULL);
/* Ignore pages which errored synchronously. */
if (IS_ERR(page)) {
ntfs_debug("Sync read_cache_page() error. Skipping "
ntfs_debug("read_mapping_page() error. Skipping "
"page (index 0x%lx).", index);
nr_free -= PAGE_CACHE_SIZE * 8;
continue;
}
wait_on_page_locked(page);
/* Ignore pages which errored asynchronously. */
if (!PageUptodate(page)) {
ntfs_debug("Async read_cache_page() error. Skipping "
"page (index 0x%lx).", index);
page_cache_release(page);
nr_free -= PAGE_CACHE_SIZE * 8;
continue;
}
kaddr = (u32*)kmap_atomic(page, KM_USER0);
/*
* For each 4 bytes, subtract the number of set bits. If this
@@ -2562,7 +2551,6 @@ static unsigned long __get_nr_free_mft_records(ntfs_volume *vol,
{
u32 *kaddr;
struct address_space *mapping = vol->mftbmp_ino->i_mapping;
filler_t *readpage = (filler_t*)mapping->a_ops->readpage;
struct page *page;
pgoff_t index;
@@ -2576,24 +2564,14 @@ static unsigned long __get_nr_free_mft_records(ntfs_volume *vol,
* Read the page from page cache, getting it from backing store
* if necessary, and increment the use count.
*/
page = read_cache_page(mapping, index, (filler_t*)readpage,
NULL);
page = read_mapping_page(mapping, index, NULL);
/* Ignore pages which errored synchronously. */
if (IS_ERR(page)) {
ntfs_debug("Sync read_cache_page() error. Skipping "
ntfs_debug("read_mapping_page() error. Skipping "
"page (index 0x%lx).", index);
nr_free -= PAGE_CACHE_SIZE * 8;
continue;
}
wait_on_page_locked(page);
/* Ignore pages which errored asynchronously. */
if (!PageUptodate(page)) {
ntfs_debug("Async read_cache_page() error. Skipping "
"page (index 0x%lx).", index);
page_cache_release(page);
nr_free -= PAGE_CACHE_SIZE * 8;
continue;
}
kaddr = (u32*)kmap_atomic(page, KM_USER0);
/*
* For each 4 bytes, subtract the number of set bits. If this