The patch titled Subject: filemap: assign current->backing_dev_info in generic_perform_write has been added to the -mm mm-unstable branch. Its filename is filemap-assign-current-backing_dev_info-in-generic_perform_write.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/filemap-assign-current-backing_dev_info-in-generic_perform_write.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Christoph Hellwig <hch@xxxxxx> Subject: filemap: assign current->backing_dev_info in generic_perform_write Date: Fri, 19 May 2023 11:35:11 +0200 Move the assignment to current->backing_dev_info from the callers into generic_perform_write to reduce boiler plate code and reduce the scope to just around the page dirtying loop. Link: https://lkml.kernel.org/r/20230519093521.133226-4-hch@xxxxxx Signed-off-by: Christoph Hellwig <hch@xxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Andreas Gruenbacher <agruenba@xxxxxxxxxx> Cc: Anna Schumaker <anna@xxxxxxxxxx> Cc: Chao Yu <chao@xxxxxxxxxx> Cc: Christian Brauner <brauner@xxxxxxxxxx> Cc: Damien Le Moal <dlemoal@xxxxxxxxxx> Cc: Darrick J. Wong <djwong@xxxxxxxxxx> Cc: Ilya Dryomov <idryomov@xxxxxxxxx> Cc: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Miklos Szeredi <miklos@xxxxxxxxxx> Cc: Theodore Ts'o <tytso@xxxxxxx> Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Cc: Xiubo Li <xiubli@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ceph/file.c | 4 ---- fs/ext4/file.c | 3 --- fs/f2fs/file.c | 2 -- fs/nfs/file.c | 5 +---- mm/filemap.c | 2 ++ 5 files changed, 3 insertions(+), 13 deletions(-) --- a/fs/ceph/file.c~filemap-assign-current-backing_dev_info-in-generic_perform_write +++ a/fs/ceph/file.c @@ -1791,9 +1791,6 @@ retry_snap: else ceph_start_io_write(inode); - /* We can write back this queue in page reclaim */ - current->backing_dev_info = inode_to_bdi(inode); - if (iocb->ki_flags & IOCB_APPEND) { err = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE, false); if (err < 0) @@ -1938,7 +1935,6 @@ out: ceph_end_io_write(inode); out_unlocked: ceph_free_cap_flush(prealloc_cf); - current->backing_dev_info = NULL; return written ? written : err; } --- a/fs/ext4/file.c~filemap-assign-current-backing_dev_info-in-generic_perform_write +++ a/fs/ext4/file.c @@ -29,7 +29,6 @@ #include <linux/pagevec.h> #include <linux/uio.h> #include <linux/mman.h> -#include <linux/backing-dev.h> #include "ext4.h" #include "ext4_jbd2.h" #include "xattr.h" @@ -285,9 +284,7 @@ static ssize_t ext4_buffered_write_iter( if (ret <= 0) goto out; - current->backing_dev_info = inode_to_bdi(inode); ret = generic_perform_write(iocb, from); - current->backing_dev_info = NULL; out: inode_unlock(inode); --- a/fs/f2fs/file.c~filemap-assign-current-backing_dev_info-in-generic_perform_write +++ a/fs/f2fs/file.c @@ -4517,9 +4517,7 @@ static ssize_t f2fs_buffered_write_iter( if (iocb->ki_flags & IOCB_NOWAIT) return -EOPNOTSUPP; - current->backing_dev_info = inode_to_bdi(inode); ret = generic_perform_write(iocb, from); - current->backing_dev_info = NULL; if (ret > 0) { f2fs_update_iostat(F2FS_I_SB(inode), inode, --- a/fs/nfs/file.c~filemap-assign-current-backing_dev_info-in-generic_perform_write +++ a/fs/nfs/file.c @@ -648,11 +648,8 @@ ssize_t nfs_file_write(struct kiocb *ioc since = filemap_sample_wb_err(file->f_mapping); nfs_start_io_write(inode); result = generic_write_checks(iocb, from); - if (result > 0) { - current->backing_dev_info = inode_to_bdi(inode); + if (result > 0) result = generic_perform_write(iocb, from); - current->backing_dev_info = NULL; - } nfs_end_io_write(inode); if (result <= 0) goto out; --- a/mm/filemap.c~filemap-assign-current-backing_dev_info-in-generic_perform_write +++ a/mm/filemap.c @@ -3865,6 +3865,7 @@ ssize_t generic_perform_write(struct kio long status = 0; ssize_t written = 0; + current->backing_dev_info = inode_to_bdi(mapping->host); do { struct page *page; unsigned long offset; /* Offset into pagecache page */ @@ -3929,6 +3930,7 @@ again: balance_dirty_pages_ratelimited(mapping); } while (iov_iter_count(i)); + current->backing_dev_info = NULL; if (!written) return status; _ Patches currently in -mm which might be from hch@xxxxxx are iomap-update-ki_pos-a-little-later-in-iomap_dio_complete.patch filemap-update-ki_pos-in-generic_perform_write.patch filemap-assign-current-backing_dev_info-in-generic_perform_write.patch filemap-add-a-kiocb_write_and_wait-helper.patch filemap-add-a-kiocb_invalidate_pages-helper.patch filemap-add-a-kiocb_invalidate_post_write-helper.patch iomap-update-ki_pos-in-iomap_file_buffered_write.patch iomap-assign-current-backing_dev_info-in-iomap_file_buffered_write.patch iomap-use-kiocb_write_and_wait-and-kiocb_invalidate_pages.patch fs-factor-out-a-direct_write_fallback-helper.patch fuse-update-ki_pos-in-fuse_perform_write.patch fuse-drop-redundant-arguments-to-fuse_perform_write.patch fuse-use-direct_write_fallback.patch squashfs-dont-include-buffer_headh.patch