From: Christoph Hellwig Date: Tue, 10 Jun 2025 05:49:42 +0000 (+0200) Subject: mm: remove the for_reclaim field from struct writeback_control X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a8fb49c6abbbe5c71e1a8a888ef2c4b3e341d169;p=thirdparty%2Fkernel%2Flinux.git mm: remove the for_reclaim field from struct writeback_control This field is now only set to one in the i915 gem code that only calls writeback_iter on it, which ignores the flag. All other checks are thuse dead code and the field can be removed. Link: https://lkml.kernel.org/r/20250610054959.2057526-7-hch@lst.de Signed-off-by: Christoph Hellwig Cc: Baolin Wang Cc: Chengming Zhou Cc: Hugh Dickins Cc: Johannes Weiner Cc: Matthew Wilcox (Oracle) Cc: Nhat Pham Signed-off-by: Andrew Morton --- diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c index 24d8daa4fdb35..f263615f6eceb 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c @@ -302,7 +302,6 @@ void __shmem_writeback(size_t size, struct address_space *mapping) .nr_to_write = SWAP_CLUSTER_MAX, .range_start = 0, .range_end = LLONG_MAX, - .for_reclaim = 1, }; struct folio *folio = NULL; int error = 0; diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 47006d0753f1c..95a657a577868 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1927,17 +1927,6 @@ int fuse_write_inode(struct inode *inode, struct writeback_control *wbc) struct fuse_file *ff; int err; - /* - * Inode is always written before the last reference is dropped and - * hence this should not be reached from reclaim. - * - * Writing back the inode from reclaim can deadlock if the request - * processing itself needs an allocation. Allocations triggering - * reclaim while serving a request can't be prevented, because it can - * involve any number of unrelated userspace processes. - */ - WARN_ON(wbc->for_reclaim); - ff = __fuse_write_file_get(fi); err = fuse_flush_times(inode, ff); if (ff) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 374fc6b34c795..cf1d720b82517 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -720,7 +720,7 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc) nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES); if (!(mntflags & NFS_MOUNT_WRITE_EAGER) || wbc->for_kupdate || - wbc->for_background || wbc->for_sync || wbc->for_reclaim) { + wbc->for_background || wbc->for_sync) { ioc = nfs_io_completion_alloc(GFP_KERNEL); if (ioc) nfs_io_completion_init(ioc, nfs_io_completion_commit, diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 9e960f2faf794..a2848d731a466 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -59,7 +59,6 @@ struct writeback_control { unsigned for_kupdate:1; /* A kupdate writeback */ unsigned for_background:1; /* A background writeback */ unsigned tagged_writepages:1; /* tag-and-write to avoid livelock */ - unsigned for_reclaim:1; /* Invoked from the page allocator */ unsigned range_cyclic:1; /* range_start is cyclic */ unsigned for_sync:1; /* sync(2) WB_SYNC_ALL writeback */ unsigned unpinned_netfs_wb:1; /* Cleared I_PINNING_NETFS_WB */ diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h index bebc252db8654..0adc40f5e72b6 100644 --- a/include/trace/events/btrfs.h +++ b/include/trace/events/btrfs.h @@ -686,7 +686,6 @@ DECLARE_EVENT_CLASS(btrfs__writepage, __field( loff_t, range_start ) __field( loff_t, range_end ) __field( char, for_kupdate ) - __field( char, for_reclaim ) __field( char, range_cyclic ) __field( unsigned long, writeback_index ) __field( u64, root_objectid ) @@ -700,7 +699,6 @@ DECLARE_EVENT_CLASS(btrfs__writepage, __entry->range_start = wbc->range_start; __entry->range_end = wbc->range_end; __entry->for_kupdate = wbc->for_kupdate; - __entry->for_reclaim = wbc->for_reclaim; __entry->range_cyclic = wbc->range_cyclic; __entry->writeback_index = inode->i_mapping->writeback_index; __entry->root_objectid = btrfs_root_id(BTRFS_I(inode)->root); @@ -709,13 +707,12 @@ DECLARE_EVENT_CLASS(btrfs__writepage, TP_printk_btrfs("root=%llu(%s) ino=%llu page_index=%lu " "nr_to_write=%ld pages_skipped=%ld range_start=%llu " "range_end=%llu for_kupdate=%d " - "for_reclaim=%d range_cyclic=%d writeback_index=%lu", + "range_cyclic=%d writeback_index=%lu", show_root_type(__entry->root_objectid), __entry->ino, __entry->index, __entry->nr_to_write, __entry->pages_skipped, __entry->range_start, __entry->range_end, - __entry->for_kupdate, - __entry->for_reclaim, __entry->range_cyclic, + __entry->for_kupdate, __entry->range_cyclic, __entry->writeback_index) ); diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index 0ff388131fc95..1e23919c0da98 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -459,7 +459,6 @@ DECLARE_EVENT_CLASS(wbc_class, __field(int, sync_mode) __field(int, for_kupdate) __field(int, for_background) - __field(int, for_reclaim) __field(int, range_cyclic) __field(long, range_start) __field(long, range_end) @@ -473,23 +472,20 @@ DECLARE_EVENT_CLASS(wbc_class, __entry->sync_mode = wbc->sync_mode; __entry->for_kupdate = wbc->for_kupdate; __entry->for_background = wbc->for_background; - __entry->for_reclaim = wbc->for_reclaim; __entry->range_cyclic = wbc->range_cyclic; __entry->range_start = (long)wbc->range_start; __entry->range_end = (long)wbc->range_end; __entry->cgroup_ino = __trace_wbc_assign_cgroup(wbc); ), - TP_printk("bdi %s: towrt=%ld skip=%ld mode=%d kupd=%d " - "bgrd=%d reclm=%d cyclic=%d " - "start=0x%lx end=0x%lx cgroup_ino=%lu", + TP_printk("bdi %s: towrt=%ld skip=%ld mode=%d kupd=%d bgrd=%d " + "cyclic=%d start=0x%lx end=0x%lx cgroup_ino=%lu", __entry->name, __entry->nr_to_write, __entry->pages_skipped, __entry->sync_mode, __entry->for_kupdate, __entry->for_background, - __entry->for_reclaim, __entry->range_cyclic, __entry->range_start, __entry->range_end,