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ocfs2: Fix deadlock when allocating page

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We cannot call grab_cache_page() when holding filesystem locks or with
a transaction started as grab_cache_page() calls page allocation with
GFP_KERNEL flag and thus page reclaim can recurse back into the filesystem
causing deadlocks or various assertion failures. We have to use
find_or_create_page() instead and pass it GFP_NOFS as we do with other
allocations.

Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tao Ma <tao.ma@oracle.com>
This commit is contained in:
Jan Kara 2010-08-24 14:28:03 +02:00 committed by Tao Ma
parent b2b6ebf5f7
commit 9b4c0ff32c
3 changed files with 5 additions and 4 deletions
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2
fs/ocfs2/alloc.c
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@ -6672,7 +6672,7 @@ int ocfs2_grab_pages(struct inode *inode, loff_t start, loff_t end,
last_page_bytes = PAGE_ALIGN(end);
index = start >> PAGE_CACHE_SHIFT;
do {
pages[numpages] = grab_cache_page(mapping, index);
pages[numpages] = find_or_create_page(mapping, index, GFP_NOFS);
if (!pages[numpages]) {
ret = -ENOMEM;
mlog_errno(ret);

2
fs/ocfs2/file.c
View file

@ -783,7 +783,7 @@ static int ocfs2_write_zero_page(struct inode *inode, u64 abs_from,
BUG_ON(abs_to > (((u64)index + 1) << PAGE_CACHE_SHIFT));
BUG_ON(abs_from & (inode->i_blkbits - 1));
page = grab_cache_page(mapping, index);
page = find_or_create_page(mapping, index, GFP_NOFS);
if (!page) {
ret = -ENOMEM;
mlog_errno(ret);

5
fs/ocfs2/refcounttree.c
View file

@ -2960,7 +2960,7 @@ static int ocfs2_duplicate_clusters_by_page(handle_t *handle,
if (map_end & (PAGE_CACHE_SIZE - 1))
to = map_end & (PAGE_CACHE_SIZE - 1);
page = grab_cache_page(mapping, page_index);
page = find_or_create_page(mapping, page_index, GFP_NOFS);
/*
* In case PAGE_CACHE_SIZE <= CLUSTER_SIZE, This page
@ -3179,7 +3179,8 @@ static int ocfs2_cow_sync_writeback(struct super_block *sb,
if (map_end > end)
map_end = end;
page = grab_cache_page(context->inode->i_mapping, page_index);
page = find_or_create_page(context->inode->i_mapping,
page_index, GFP_NOFS);
BUG_ON(!page);
wait_on_page_writeback(page);