On Fri, May 19, 2023 at 11:35:16AM +0200, Christoph Hellwig wrote: > Move the assignment to current->backing_dev_info from the callers into > iomap_file_buffered_write to reduce boiler plate code and reduce the > scope to just around the page dirtying loop. > > Note that zonefs was missing this assignment before. I'm still wondering (a) what the hell current->backing_dev_info is for, and (b) if we need it around the iomap_unshare operation. $ git grep current..backing_dev_info fs/btrfs/file.c:1148: current->backing_dev_info = inode_to_bdi(inode); fs/btrfs/file.c:1169: current->backing_dev_info = NULL; fs/btrfs/file.c:1692: current->backing_dev_info = NULL; fs/ceph/file.c:1795: current->backing_dev_info = inode_to_bdi(inode); fs/ceph/file.c:1943: current->backing_dev_info = NULL; fs/ext4/file.c:288: current->backing_dev_info = inode_to_bdi(inode); fs/ext4/file.c:290: current->backing_dev_info = NULL; fs/f2fs/file.c:4520: current->backing_dev_info = inode_to_bdi(inode); fs/f2fs/file.c:4522: current->backing_dev_info = NULL; fs/fuse/file.c:1366: current->backing_dev_info = inode_to_bdi(inode); fs/fuse/file.c:1412: current->backing_dev_info = NULL; fs/gfs2/file.c:1044: current->backing_dev_info = inode_to_bdi(inode); fs/gfs2/file.c:1048: current->backing_dev_info = NULL; fs/nfs/file.c:652: current->backing_dev_info = inode_to_bdi(inode); fs/nfs/file.c:654: current->backing_dev_info = NULL; fs/ntfs/file.c:1914: current->backing_dev_info = inode_to_bdi(vi); fs/ntfs/file.c:1918: current->backing_dev_info = NULL; fs/ntfs3/file.c:823: current->backing_dev_info = inode_to_bdi(inode); fs/ntfs3/file.c:996: current->backing_dev_info = NULL; fs/xfs/xfs_file.c:721: current->backing_dev_info = inode_to_bdi(inode); fs/xfs/xfs_file.c:756: current->backing_dev_info = NULL; mm/filemap.c:3995: current->backing_dev_info = inode_to_bdi(inode); mm/filemap.c:4056: current->backing_dev_info = NULL; AFAICT nobody uses it at all? Unless there's some bizarre user that isn't extracting it from @current? Oh, hey, new question (c) isn't this set incorrectly for xfs realtime files? --D > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > --- > fs/gfs2/file.c | 3 --- > fs/iomap/buffered-io.c | 3 +++ > fs/xfs/xfs_file.c | 5 ----- > 3 files changed, 3 insertions(+), 8 deletions(-) > > diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c > index 499ef174dec138..261897fcfbc495 100644 > --- a/fs/gfs2/file.c > +++ b/fs/gfs2/file.c > @@ -25,7 +25,6 @@ > #include <linux/dlm.h> > #include <linux/dlm_plock.h> > #include <linux/delay.h> > -#include <linux/backing-dev.h> > #include <linux/fileattr.h> > > #include "gfs2.h" > @@ -1041,11 +1040,9 @@ static ssize_t gfs2_file_buffered_write(struct kiocb *iocb, > goto out_unlock; > } > > - current->backing_dev_info = inode_to_bdi(inode); > pagefault_disable(); > ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops); > pagefault_enable(); > - current->backing_dev_info = NULL; > if (ret > 0) > written += ret; > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index 550525a525c45c..b2779bd1f10611 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -3,6 +3,7 @@ > * Copyright (C) 2010 Red Hat, Inc. > * Copyright (C) 2016-2019 Christoph Hellwig. > */ > +#include <linux/backing-dev.h> > #include <linux/module.h> > #include <linux/compiler.h> > #include <linux/fs.h> > @@ -869,8 +870,10 @@ iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *i, > if (iocb->ki_flags & IOCB_NOWAIT) > iter.flags |= IOMAP_NOWAIT; > > + current->backing_dev_info = inode_to_bdi(iter.inode); > while ((ret = iomap_iter(&iter, ops)) > 0) > iter.processed = iomap_write_iter(&iter, i); > + current->backing_dev_info = NULL; > > if (unlikely(ret < 0)) > return ret; > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index bfba10e0b0f3c2..98d763cc3b114c 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -27,7 +27,6 @@ > > #include <linux/dax.h> > #include <linux/falloc.h> > -#include <linux/backing-dev.h> > #include <linux/mman.h> > #include <linux/fadvise.h> > #include <linux/mount.h> > @@ -717,9 +716,6 @@ xfs_file_buffered_write( > if (ret) > goto out; > > - /* We can write back this queue in page reclaim */ > - current->backing_dev_info = inode_to_bdi(inode); > - > trace_xfs_file_buffered_write(iocb, from); > ret = iomap_file_buffered_write(iocb, from, > &xfs_buffered_write_iomap_ops); > @@ -751,7 +747,6 @@ xfs_file_buffered_write( > goto write_retry; > } > > - current->backing_dev_info = NULL; > out: > if (iolock) > xfs_iunlock(ip, iolock); > -- > 2.39.2 >
