| Message ID | 20210118193516.2915706-3-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/11] xfs: factor out a xfs_ilock_iocb helper | expand |
On Tue, Jan 19, 2021 at 09:33:37AM -0300, Raphael Carvalho wrote: > > * No fallback to buffered IO after short writes for XFS, direct > > I/O > > @@ -632,7 +648,8 @@ xfs_file_dax_write( > > error = xfs_setfilesize(ip, pos, ret); > > } > > out: > > - xfs_iunlock(ip, iolock); > > + if (iolock) > > + xfs_iunlock(ip, iolock); > > > > Not familiar with the code but looks like you're setting *iolock to zero on > error and perhaps you want to dereference it here instead In this function iolock is a scalar value, not a pointer. xfs_file_aio_write_checks gets it passed by reference and clears it, and here we check that the iolock is locked at all.
On Mon, Jan 18, 2021 at 08:35:07PM +0100, Christoph Hellwig wrote: > Ensure we don't block on the iolock, or waiting for I/O in > xfs_file_aio_write_checks if the caller asked to avoid that. > > Fixes: 29a5d29ec181 ("xfs: nowait aio support") > Signed-off-by: Christoph Hellwig <hch@lst.de> > Reviewed-by: Dave Chinner <dchinner@redhat.com> > Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > --- > fs/xfs/xfs_file.c | 25 +++++++++++++++++++++---- > 1 file changed, 21 insertions(+), 4 deletions(-) > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index c441cddfa4acbc..fb4e6f2852bb8b 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -335,7 +335,14 @@ xfs_file_aio_write_checks( > if (error <= 0) > return error; > > - error = xfs_break_layouts(inode, iolock, BREAK_WRITE); > + if (iocb->ki_flags & IOCB_NOWAIT) { > + error = break_layout(inode, false); > + if (error == -EWOULDBLOCK) > + error = -EAGAIN; > + } else { > + error = xfs_break_layouts(inode, iolock, BREAK_WRITE); > + } > + > if (error) > return error; > > @@ -346,7 +353,11 @@ xfs_file_aio_write_checks( > if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) { > xfs_iunlock(ip, *iolock); > *iolock = XFS_IOLOCK_EXCL; > - xfs_ilock(ip, *iolock); > + error = xfs_ilock_iocb(iocb, *iolock); > + if (error) { > + *iolock = 0; > + return error; > + } > goto restart; > } > /* > @@ -368,6 +379,10 @@ xfs_file_aio_write_checks( > isize = i_size_read(inode); > if (iocb->ki_pos > isize) { > spin_unlock(&ip->i_flags_lock); > + > + if (iocb->ki_flags & IOCB_NOWAIT) > + return -EAGAIN; > + > if (!drained_dio) { > if (*iolock == XFS_IOLOCK_SHARED) { > xfs_iunlock(ip, *iolock); > @@ -593,7 +608,8 @@ xfs_file_dio_aio_write( > &xfs_dio_write_ops, > is_sync_kiocb(iocb) || unaligned_io); > out: > - xfs_iunlock(ip, iolock); > + if (iolock) > + xfs_iunlock(ip, iolock); > > /* > * No fallback to buffered IO after short writes for XFS, direct I/O > @@ -632,7 +648,8 @@ xfs_file_dax_write( > error = xfs_setfilesize(ip, pos, ret); > } > out: > - xfs_iunlock(ip, iolock); > + if (iolock) > + xfs_iunlock(ip, iolock); > if (error) > return error; > > -- > 2.29.2 >
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index c441cddfa4acbc..fb4e6f2852bb8b 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -335,7 +335,14 @@ xfs_file_aio_write_checks( if (error <= 0) return error; - error = xfs_break_layouts(inode, iolock, BREAK_WRITE); + if (iocb->ki_flags & IOCB_NOWAIT) { + error = break_layout(inode, false); + if (error == -EWOULDBLOCK) + error = -EAGAIN; + } else { + error = xfs_break_layouts(inode, iolock, BREAK_WRITE); + } + if (error) return error; @@ -346,7 +353,11 @@ xfs_file_aio_write_checks( if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) { xfs_iunlock(ip, *iolock); *iolock = XFS_IOLOCK_EXCL; - xfs_ilock(ip, *iolock); + error = xfs_ilock_iocb(iocb, *iolock); + if (error) { + *iolock = 0; + return error; + } goto restart; } /* @@ -368,6 +379,10 @@ xfs_file_aio_write_checks( isize = i_size_read(inode); if (iocb->ki_pos > isize) { spin_unlock(&ip->i_flags_lock); + + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; + if (!drained_dio) { if (*iolock == XFS_IOLOCK_SHARED) { xfs_iunlock(ip, *iolock); @@ -593,7 +608,8 @@ xfs_file_dio_aio_write( &xfs_dio_write_ops, is_sync_kiocb(iocb) || unaligned_io); out: - xfs_iunlock(ip, iolock); + if (iolock) + xfs_iunlock(ip, iolock); /* * No fallback to buffered IO after short writes for XFS, direct I/O @@ -632,7 +648,8 @@ xfs_file_dax_write( error = xfs_setfilesize(ip, pos, ret); } out: - xfs_iunlock(ip, iolock); + if (iolock) + xfs_iunlock(ip, iolock); if (error) return error;
Ensure we don't block on the iolock, or waiting for I/O in xfs_file_aio_write_checks if the caller asked to avoid that. Fixes: 29a5d29ec181 ("xfs: nowait aio support") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> --- fs/xfs/xfs_file.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-)