diff options
Diffstat (limited to 'fs/f2fs/data.c')
| -rw-r--r-- | fs/f2fs/data.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 20f31ff47e05..44645f4f914b 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2298,6 +2298,7 @@ static int f2fs_mpage_readpages(struct inode *inode, unsigned nr_pages = rac ? readahead_count(rac) : 1; unsigned max_nr_pages = nr_pages; int ret = 0; + bool drop_ra = false; map.m_pblk = 0; map.m_lblk = 0; @@ -2308,10 +2309,26 @@ static int f2fs_mpage_readpages(struct inode *inode, map.m_seg_type = NO_CHECK_TYPE; map.m_may_create = false; + /* + * Two readahead threads for same address range can cause race condition + * which fragments sequential read IOs. So let's avoid each other. + */ + if (rac && readahead_count(rac)) { + if (READ_ONCE(F2FS_I(inode)->ra_offset) == readahead_index(rac)) + drop_ra = true; + else + WRITE_ONCE(F2FS_I(inode)->ra_offset, + readahead_index(rac)); + } + for (; nr_pages; nr_pages--) { if (rac) { page = readahead_page(rac); prefetchw(&page->flags); + if (drop_ra) { + f2fs_put_page(page, 1); + continue; + } } #ifdef CONFIG_F2FS_FS_COMPRESSION @@ -2374,6 +2391,9 @@ next_page: } if (bio) __submit_bio(F2FS_I_SB(inode), bio, DATA); + + if (rac && readahead_count(rac) && !drop_ra) + WRITE_ONCE(F2FS_I(inode)->ra_offset, -1); return ret; } |