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| author | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2013-01-25 18:33:41 +0900 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2013-02-12 07:15:00 +0900 |
| commit | bd43df021ac37247f2db58ff376fb4032170f754 (patch) | |
| tree | e22482138f5ea62d84a1cbe327e0f546670b1a06 /fs/f2fs | |
| parent | 577e349514452fa3fcd99fd06e587b02d3d1cf28 (diff) | |
| download | linux-bd43df021ac37247f2db58ff376fb4032170f754.tar.bz2 | |
f2fs: cover global locks for reserve_new_block
The fill_zero() from fallocate() calls get_new_data_page() in which calls
reserve_new_block().
The reserve_new_block() should be covered by *DATA_NEW*, one of global locks.
And also, before getting the lock, we should check free sections by calling
f2fs_balance_fs().
If we break this rule, f2fs is able to face with out-of-control free space
management and fall into infinite loop like the following scenario as well.
[f2fs_sync_fs()] [fallocate()]
- write_checkpoint() - fill_zero()
- block_operations() - get_new_data_page()
: grab NODE_NEW - get_dnode_of_data()
: get locked dirty node page
- sync_node_pages()
: try to grab NODE_NEW for data allocation
: trylock and skip the dirty node page
: call sync_node_pages() repeatedly in order to flush all the dirty node
pages!
In order to avoid this, we should grab another global lock such as DATA_NEW
before calling get_new_data_page() in fill_zero().
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Diffstat (limited to 'fs/f2fs')
| -rw-r--r-- | fs/f2fs/file.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 3191b52aafb0..6cdab2c64fc6 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -387,12 +387,17 @@ const struct inode_operations f2fs_file_inode_operations = { static void fill_zero(struct inode *inode, pgoff_t index, loff_t start, loff_t len) { + struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); struct page *page; if (!len) return; + f2fs_balance_fs(sbi); + + mutex_lock_op(sbi, DATA_NEW); page = get_new_data_page(inode, index, false); + mutex_unlock_op(sbi, DATA_NEW); if (!IS_ERR(page)) { wait_on_page_writeback(page); |