On 26.11.2019 15:44, Jaegeuk Kim wrote:
On 11/26, Damien Le Moal wrote:f2fs_preallocate_blocks() identifies direct IOs using the IOCB_DIRECT flag for a kiocb structure. However, the file system direct IO handler function f2fs_direct_IO() may have decided that a direct IO has to be exececuted as a buffered IO using the function f2fs_force_buffered_io(). This is the case for instance for volumes including zoned block device and for unaligned write IOs with LFS mode enabled. These 2 different methods of identifying direct IOs can result in inconsistencies generating stale data access for direct reads after a direct IO write that is treated as a buffered write. Fix this inconsistency by combining the IOCB_DIRECT flag test with the result of f2fs_force_buffered_io(). Reported-by: Javier Gonzalez <javier@xxxxxxxxxxx> Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx> --- fs/f2fs/data.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 5755e897a5f0..8ac2d3b70022 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1073,6 +1073,8 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from) int flag; int err = 0; bool direct_io = iocb->ki_flags & IOCB_DIRECT; + bool do_direct_io = direct_io && + !f2fs_force_buffered_io(inode, iocb, from); /* convert inline data for Direct I/O*/ if (direct_io) { @@ -1081,7 +1083,7 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from) return err; } - if (direct_io && allow_outplace_dio(inode, iocb, from)) + if (do_direct_io && allow_outplace_dio(inode, iocb, from))It seems f2fs_force_buffered_io() includes allow_outplace_dio(). How about this? --- fs/f2fs/data.c | 13 ------------- fs/f2fs/file.c | 35 +++++++++++++++++++++++++---------- 2 files changed, 25 insertions(+), 23 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index a034cd0ce021..fc40a72f7827 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1180,19 +1180,6 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from) int err = 0; bool direct_io = iocb->ki_flags & IOCB_DIRECT; - /* convert inline data for Direct I/O*/ - if (direct_io) { - err = f2fs_convert_inline_inode(inode); - if (err) - return err; - } - - if (direct_io && allow_outplace_dio(inode, iocb, from)) - return 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) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index c0560d62dbee..6b32ac6c3382 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -3386,18 +3386,33 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) ret = -EAGAIN; goto out; } - } else { - preallocated = true; - target_size = iocb->ki_pos + iov_iter_count(from); + goto write; + } - err = f2fs_preallocate_blocks(iocb, from); - if (err) { - clear_inode_flag(inode, FI_NO_PREALLOC); - inode_unlock(inode); - ret = err; - goto out; - } + if (is_inode_flag_set(inode, FI_NO_PREALLOC)) + goto write; + + if (iocb->ki_flags & IOCB_DIRECT) { + /* convert inline data for Direct I/O*/ + err = f2fs_convert_inline_inode(inode); + if (err) + goto out_err; + + if (!f2fs_force_buffered_io(inode, iocb, from)) + goto write; + } + preallocated = true; + target_size = iocb->ki_pos + iov_iter_count(from); + + err = f2fs_preallocate_blocks(iocb, from); + if (err) { +out_err: + clear_inode_flag(inode, FI_NO_PREALLOC); + inode_unlock(inode); + ret = err; + goto out; } +write: ret = __generic_file_write_iter(iocb, from); clear_inode_flag(inode, FI_NO_PREALLOC); -- 2.19.0.605.g01d371f741-goog
This also addresses the original problem. Tested-by: Javier González <javier@xxxxxxxxxxx>
