Re: [PATCH v2 3/6] iomap: modify ->end_io() calling convention
From: Matthew Bobrowski <hidden>
Date: 2019-09-08 23:32:38
Also in:
linux-fsdevel, linux-xfs
+ CC: linux-xfs@vger.kernel.org On Mon, Sep 09, 2019 at 09:19:31AM +1000, Matthew Bobrowski wrote:
This patch modifies the calling convention for the iomap ->end_io() callback. Rather than passing either dio->error or dio->size as the 'size' argument, we instead pass both dio->error and dio->size values separately. In the instance that an error occurred during a write, we currently cannot determine whether any blocks have been allocated beyond the current EOF and data has subsequently been written to these blocks within the ->end_io() callback. As a result, we cannot judge whether we should take the truncate failed write path. Having both dio->error and dio->size will allow us to perform such checks within this callback. Signed-off-by: Matthew Bobrowski <redacted>
Please note, this patch is now part of the recent end_io improvements posted through by Christoph, and can be found here: https://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git/commit/?h=iomap-5.4-merge&id=db10bd824bc0353702231f1294b58903cb66bac7.
quoted hunk ↗ jump to hunk
--- fs/iomap/direct-io.c | 9 +++------ fs/xfs/xfs_file.c | 8 +++++--- include/linux/iomap.h | 4 ++-- 3 files changed, 10 insertions(+), 11 deletions(-)diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 10517cea9682..2ccf1c6460d4 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c@@ -77,13 +77,10 @@ static ssize_t iomap_dio_complete(struct iomap_dio *dio) loff_t offset = iocb->ki_pos; ssize_t ret; - if (dio->end_io) { - ret = dio->end_io(iocb, - dio->error ? dio->error : dio->size, - dio->flags); - } else { + if (dio->end_io) + ret = dio->end_io(iocb, dio->size, dio->error, dio->flags); + else ret = dio->error; - } if (likely(!ret)) { ret = dio->size;diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 28101bbc0b78..d49759008c54 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c@@ -369,21 +369,23 @@ static int xfs_dio_write_end_io( struct kiocb *iocb, ssize_t size, + int error, unsigned flags) { struct inode *inode = file_inode(iocb->ki_filp); struct xfs_inode *ip = XFS_I(inode); loff_t offset = iocb->ki_pos; unsigned int nofs_flag; - int error = 0; trace_xfs_end_io_direct_write(ip, offset, size); if (XFS_FORCED_SHUTDOWN(ip->i_mount)) return -EIO; - if (size <= 0) - return size; + if (error) + return error; + if (!size) + return 0; /* * Capture amount written on completion as we can't reliably accountdiff --git a/include/linux/iomap.h b/include/linux/iomap.h index bc499ceae392..d983cdcf2e72 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h@@ -188,8 +188,8 @@ sector_t iomap_bmap(struct address_space *mapping, sector_t bno, */ #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */ #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */ -typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret, - unsigned flags); +typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t size, + int error, unsigned int flags); ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops, iomap_dio_end_io_t end_io); int iomap_dio_iopoll(struct kiocb *kiocb, bool spin);-- 2.20.1