From dc91de78e5e1d44238b5dd2b57d2e8e67cbc00a1 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Fri, 13 Jan 2017 13:12:29 -0800 Subject: [PATCH] f2fs: do not preallocate blocks which has wrong buffer Sheng Yong reports needless preallocation if write(small_buffer, large_size) is called. In that case, f2fs preallocates large_size, but vfs returns early due to small_buffer size. Let's detect it before preallocation phase in f2fs. Reported-by: Sheng Yong Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 6 +++++- fs/f2fs/f2fs.h | 1 + fs/f2fs/file.c | 8 +++++++- 3 files changed, 13 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 848d110dc1ca..2ea80215f26c 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -749,6 +749,9 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from) struct f2fs_map_blocks map; int err = 0; + if (is_inode_flag_set(inode, FI_NO_PREALLOC)) + return 0; + map.m_lblk = F2FS_BLK_ALIGN(iocb->ki_pos); map.m_len = F2FS_BYTES_TO_BLK(iocb->ki_pos + iov_iter_count(from)); if (map.m_len > map.m_lblk) @@ -1653,7 +1656,8 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi, * we already allocated all the blocks, so we don't need to get * the block addresses when there is no need to fill the page. */ - if (!f2fs_has_inline_data(inode) && len == PAGE_SIZE) + if (!f2fs_has_inline_data(inode) && len == PAGE_SIZE && + !is_inode_flag_set(inode, FI_NO_PREALLOC)) return 0; if (f2fs_has_inline_data(inode) || diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 5d9731036306..0045ef9a9ad2 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1665,6 +1665,7 @@ enum { FI_INLINE_DOTS, /* indicate inline dot dentries */ FI_DO_DEFRAG, /* indicate defragment is running */ FI_DIRTY_FILE, /* indicate regular/symlink has dirty pages */ + FI_NO_PREALLOC, /* indicate skipped preallocated blocks */ }; static inline void __mark_inode_dirty_flag(struct inode *inode, diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index e45522115b1c..9c0f469cde13 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include @@ -2258,8 +2259,12 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) inode_lock(inode); ret = generic_write_checks(iocb, from); if (ret > 0) { - int err = f2fs_preallocate_blocks(iocb, from); + int err; + if (iov_iter_fault_in_readable(from, iov_iter_count(from))) + set_inode_flag(inode, FI_NO_PREALLOC); + + err = f2fs_preallocate_blocks(iocb, from); if (err) { inode_unlock(inode); return err; @@ -2267,6 +2272,7 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) blk_start_plug(&plug); ret = __generic_file_write_iter(iocb, from); blk_finish_plug(&plug); + clear_inode_flag(inode, FI_NO_PREALLOC); } inode_unlock(inode); -- 2.30.2