Merge tag 'for-6.13-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "Changes outside of btrfs: add io_uring command flag to track a dying
  task (the rest will go via the block git tree).

  User visible changes:

   - wire encoded read (ioctl) to io_uring commands, this can be used on
     itself, in the future this will allow 'send' to be asynchronous. As
     a consequence, the encoded read ioctl can also work in non-blocking
     mode

   - new ioctl to wait for cleaned subvolumes, no need to use the
     generic and root-only SEARCH_TREE ioctl, will be used by "btrfs
     subvol sync"

   - recognize different paths/symlinks for the same devices and don't
     report them during rescanning, this can be observed with LVM or DM

   - seeding device use case change, the sprout device (the one
     capturing new writes) will not clear the read-only status of the
     super block; this prevents accumulating space from deleted
     snapshots

  Performance improvements:

   - reduce lock contention when traversing extent buffers

   - reduce extent tree lock contention when searching for inline
     backref

   - switch from rb-trees to xarray for delayed ref tracking,
     improvements due to better cache locality, branching factors and
     more compact data structures

   - enable extent map shrinker again (prevent memory exhaustion under
     some types of IO load), reworked to run in a single worker thread
     (there used to be problems causing long stalls under memory
     pressure)

  Core changes:

   - raid-stripe-tree feature updates:
       - make device replace and scrub work
       - implement partial deletion of stripe extents
       - new selftests

   - split the config option BTRFS_DEBUG and add EXPERIMENTAL for
     features that are experimental or with known problems so we don't
     misuse debugging config for that

   - subpage mode updates (sector < page):
       - update compression implementations
       - update writepage, writeback

   - continued folio API conversions:
       - buffered writes

   - make buffered write copy one page at a time, preparatory work for
     future integration with large folios, may cause performance drop

   - proper locking of root item regarding starting send

   - error handling improvements

   - code cleanups and refactoring:
       - dead code removal
       - unused parameter reduction
       - lockdep assertions"

* tag 'for-6.13-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (119 commits)
  btrfs: send: check for read-only send root under critical section
  btrfs: send: check for dead send root under critical section
  btrfs: remove check for NULL fs_info at btrfs_folio_end_lock_bitmap()
  btrfs: fix warning on PTR_ERR() against NULL device at btrfs_control_ioctl()
  btrfs: fix a typo in btrfs_use_zone_append
  btrfs: avoid superfluous calls to free_extent_map() in btrfs_encoded_read()
  btrfs: simplify logic to decrement snapshot counter at btrfs_mksnapshot()
  btrfs: remove hole from struct btrfs_delayed_node
  btrfs: update stale comment for struct btrfs_delayed_ref_node::add_list
  btrfs: add new ioctl to wait for cleaned subvolumes
  btrfs: simplify range tracking in cow_file_range()
  btrfs: remove conditional path allocation in btrfs_read_locked_inode()
  btrfs: push cleanup into btrfs_read_locked_inode()
  io_uring/cmd: let cmds to know about dying task
  btrfs: add struct io_btrfs_cmd as type for io_uring_cmd_to_pdu()
  btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)
  btrfs: move priv off stack in btrfs_encoded_read_regular_fill_pages()
  btrfs: don't sleep in btrfs_encoded_read() if IOCB_NOWAIT is set
  btrfs: change btrfs_encoded_read() so that reading of extent is done by caller
  btrfs: remove pointless iocb::ki_pos addition in btrfs_encoded_read()
  ...

1 files changed, 11 insertions, 22 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 881d62d81b9f..97a85d180b61 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -28,7 +28,6 @@
 #include <linux/btrfs.h>
 #include <linux/security.h>
 #include <linux/fs_parser.h>
-#include <linux/swap.h>
 #include "messages.h"
 #include "delayed-inode.h"
 #include "ctree.h"
@@ -946,8 +945,7 @@ static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objec
 }
 
 static int btrfs_fill_super(struct super_block *sb,
-			    struct btrfs_fs_devices *fs_devices,
-			    void *data)
+			    struct btrfs_fs_devices *fs_devices)
 {
 	struct inode *inode;
 	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
@@ -971,7 +969,7 @@ static int btrfs_fill_super(struct super_block *sb,
 		return err;
 	}
 
-	err = open_ctree(sb, fs_devices, (char *)data);
+	err = open_ctree(sb, fs_devices);
 	if (err) {
 		btrfs_err(fs_info, "open_ctree failed");
 		return err;
@@ -1893,7 +1891,7 @@ static int btrfs_get_tree_super(struct fs_context *fc)
 		snprintf(sb->s_id, sizeof(sb->s_id), "%pg", bdev);
 		shrinker_debugfs_rename(sb->s_shrink, "sb-btrfs:%s", sb->s_id);
 		btrfs_sb(sb)->bdev_holder = &btrfs_fs_type;
-		ret = btrfs_fill_super(sb, fs_devices, NULL);
+		ret = btrfs_fill_super(sb, fs_devices);
 	}
 
 	if (ret) {
@@ -2257,7 +2255,10 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
 		device = btrfs_scan_one_device(vol->name, BLK_OPEN_READ, false);
 		if (IS_ERR_OR_NULL(device)) {
 			mutex_unlock(&uuid_mutex);
-			ret = PTR_ERR(device);
+			if (IS_ERR(device))
+				ret = PTR_ERR(device);
+			else
+				ret = 0;
 			break;
 		}
 		ret = !(device->fs_devices->num_devices ==
@@ -2396,13 +2397,7 @@ static long btrfs_nr_cached_objects(struct super_block *sb, struct shrink_contro
 
 	trace_btrfs_extent_map_shrinker_count(fs_info, nr);
 
-	/*
-	 * Only report the real number for DEBUG builds, as there are reports of
-	 * serious performance degradation caused by too frequent shrinks.
-	 */
-	if (IS_ENABLED(CONFIG_BTRFS_DEBUG))
-		return nr;
-	return 0;
+	return nr;
 }
 
 static long btrfs_free_cached_objects(struct super_block *sb, struct shrink_control *sc)
@@ -2410,16 +2405,10 @@ static long btrfs_free_cached_objects(struct super_block *sb, struct shrink_cont
 	const long nr_to_scan = min_t(unsigned long, LONG_MAX, sc->nr_to_scan);
 	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 
-	/*
-	 * We may be called from any task trying to allocate memory and we don't
-	 * want to slow it down with scanning and dropping extent maps. It would
-	 * also cause heavy lock contention if many tasks concurrently enter
-	 * here. Therefore only allow kswapd tasks to scan and drop extent maps.
-	 */
-	if (!current_is_kswapd())
-		return 0;
+	btrfs_free_extent_maps(fs_info, nr_to_scan);
 
-	return btrfs_free_extent_maps(fs_info, nr_to_scan);
+	/* The extent map shrinker runs asynchronously, so always return 0. */
+	return 0;
 }
 
 static const struct super_operations btrfs_super_ops = {