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authorJin Xu <jinuxstyle@gmail.com>2013-08-05 20:02:04 +0800
committerJaegeuk Kim <jaegeuk.kim@samsung.com>2013-08-06 22:00:36 +0900
commita569469e967022d9ceeaa4b73619f96614087d2d (patch)
tree530ddfa1940ce086cbc7e3711ea01a7c7f783786 /fs/f2fs
parentdf273efc36024a9ea97fd687d638a70c3ea8c37a (diff)
downloadop-kernel-dev-a569469e967022d9ceeaa4b73619f96614087d2d.zip
op-kernel-dev-a569469e967022d9ceeaa4b73619f96614087d2d.tar.gz
f2fs: fix a deadlock in fsync
This patch fixes a deadlock bug that occurs quite often when there are concurrent write and fsync on a same file. Following is the simplified call trace when tasks get hung. fsync thread: - f2fs_sync_file ... - f2fs_write_data_pages ... - update_extent_cache ... - update_inode - wait_on_page_writeback bdi writeback thread - __writeback_single_inode - f2fs_write_data_pages - mutex_lock(sbi->writepages) The deadlock happens when the fsync thread waits on a inode page that has been added to the f2fs' cached bio sbi->bio[NODE], and unfortunately, no one else could be able to submit the cached bio to block layer for writeback. This is because the fsync thread already hold a sbi->fs_lock and the sbi->writepages lock, causing the bdi thread being blocked when attempt to write data pages for the same inode. At the same time, f2fs_gc thread does not notice the situation and could not help. Even the sync syscall gets blocked. To fix it, we could submit the cached bio first before waiting on a inode page that is being written back. Signed-off-by: Jin Xu <jinuxstyle@gmail.com> [Jaegeuk Kim: add more cases to use f2fs_wait_on_page_writeback] Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Diffstat (limited to 'fs/f2fs')
-rw-r--r--fs/f2fs/data.c2
-rw-r--r--fs/f2fs/f2fs.h3
-rw-r--r--fs/f2fs/gc.c8
-rw-r--r--fs/f2fs/inode.c2
-rw-r--r--fs/f2fs/segment.c10
5 files changed, 16 insertions, 9 deletions
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index f458883..a7eb529 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -37,7 +37,7 @@ static void __set_data_blkaddr(struct dnode_of_data *dn, block_t new_addr)
struct page *node_page = dn->node_page;
unsigned int ofs_in_node = dn->ofs_in_node;
- wait_on_page_writeback(node_page);
+ f2fs_wait_on_page_writeback(node_page, NODE, false);
rn = F2FS_NODE(node_page);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 63813be..13db10b 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1023,7 +1023,8 @@ int npages_for_summary_flush(struct f2fs_sb_info *);
void allocate_new_segments(struct f2fs_sb_info *);
struct page *get_sum_page(struct f2fs_sb_info *, unsigned int);
struct bio *f2fs_bio_alloc(struct block_device *, int);
-void f2fs_submit_bio(struct f2fs_sb_info *, enum page_type, bool sync);
+void f2fs_submit_bio(struct f2fs_sb_info *, enum page_type, bool);
+void f2fs_wait_on_page_writeback(struct page *, enum page_type, bool);
void write_meta_page(struct f2fs_sb_info *, struct page *);
void write_node_page(struct f2fs_sb_info *, struct page *, unsigned int,
block_t, block_t *);
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index d286d8b..e6b3ffd 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -422,8 +422,7 @@ next_step:
/* set page dirty and write it */
if (gc_type == FG_GC) {
- f2fs_submit_bio(sbi, NODE, true);
- wait_on_page_writeback(node_page);
+ f2fs_wait_on_page_writeback(node_page, NODE, true);
set_page_dirty(node_page);
} else {
if (!PageWriteback(node_page))
@@ -523,10 +522,7 @@ static void move_data_page(struct inode *inode, struct page *page, int gc_type)
} else {
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
- if (PageWriteback(page)) {
- f2fs_submit_bio(sbi, DATA, true);
- wait_on_page_writeback(page);
- }
+ f2fs_wait_on_page_writeback(page, DATA, true);
if (clear_page_dirty_for_io(page) &&
S_ISDIR(inode->i_mode)) {
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index debf743..9ab81e7 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -151,7 +151,7 @@ void update_inode(struct inode *inode, struct page *node_page)
struct f2fs_node *rn;
struct f2fs_inode *ri;
- wait_on_page_writeback(node_page);
+ f2fs_wait_on_page_writeback(node_page, NODE, false);
rn = F2FS_NODE(node_page);
ri = &(rn->i);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 9b74ae2..68e344f 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -705,6 +705,16 @@ retry:
trace_f2fs_submit_write_page(page, blk_addr, type);
}
+void f2fs_wait_on_page_writeback(struct page *page,
+ enum page_type type, bool sync)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
+ if (PageWriteback(page)) {
+ f2fs_submit_bio(sbi, type, sync);
+ wait_on_page_writeback(page);
+ }
+}
+
static bool __has_curseg_space(struct f2fs_sb_info *sbi, int type)
{
struct curseg_info *curseg = CURSEG_I(sbi, type);
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