Merge tag 'for-6.2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "This round there are a lot of cleanups and moved code so the diffstat
  looks huge, otherwise there are some nice performance improvements and
  an update to raid56 reliability.

  User visible features:

   - raid56 reliability vs performance trade off:
      - fix destructive RMW for raid5 data (raid6 still needs work): do
        full checksum verification for all data during RMW cycle, this
        should prevent rewriting potentially corrupted data without
        notice
      - stripes are cached in memory which should reduce the performance
        impact but still can hurt some workloads
      - checksums are verified after repair again
      - this is the last option without introducing additional features
        (write intent bitmap, journal, another tree), the extra checksum
        read/verification was supposed to be avoided by the original
        implementation exactly for performance reasons but that caused
        all the reliability problems

   - discard=async by default for devices that support it

   - implement emergency flush reserve to avoid almost all unnecessary
     transaction aborts due to ENOSPC in cases where there are too many
     delayed refs or delayed allocation

   - skip block group synchronization if there's no change in used
     bytes, can reduce transaction commit count for some workloads

  Performance improvements:

   - fiemap and lseek:
      - overall speedup due to skipping unnecessary or duplicate
        searches (-40% run time)
      - cache some data structures and sharedness of extents (-30% run
        time)

   - send:
      - faster backref resolution when finding clones
      - cached leaf to root mapping for faster backref walking
      - improved clone/sharing detection
      - overall run time improvements (-70%)

  Core:

   - module initialization converted to a table of function pointers run
     in a sequence

   - preparation for fscrypt, extend passing file names across calls,
     dir item can store encryption status

   - raid56 updates:
      - more accurate error tracking of sectors within stripe
      - simplify recovery path and remove dedicated endio worker kthread
      - simplify scrub call paths
      - refactoring to support the extra data checksum verification
        during RMW cycle

   - tree block parentness checks consolidated and done at metadata read
     time

   - improved error handling

   - cleanups:
      - move a lot of code for better synchronization between kernel and
        user space sources, split big files
      - enum cleanups
      - GFP flag cleanups
      - header file cleanups, prototypes, dependencies
      - redundant parameter cleanups
      - inline extent handling simplifications
      - inode parameter conversion
      - data structure cleanups, reductions, renames, merges"

* tag 'for-6.2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (249 commits)
  btrfs: print transaction aborted messages with an error level
  btrfs: sync some cleanups from progs into uapi/btrfs.h
  btrfs: do not BUG_ON() on ENOMEM when dropping extent items for a range
  btrfs: fix extent map use-after-free when handling missing device in read_one_chunk
  btrfs: remove outdated logic from overwrite_item() and add assertion
  btrfs: unify overwrite_item() and do_overwrite_item()
  btrfs: replace strncpy() with strscpy()
  btrfs: fix uninitialized variable in find_first_clear_extent_bit
  btrfs: fix uninitialized parent in insert_state
  btrfs: add might_sleep() annotations
  btrfs: add stack helpers for a few btrfs items
  btrfs: add nr_global_roots to the super block definition
  btrfs: remove BTRFS_LEAF_DATA_OFFSET
  btrfs: add helpers for manipulating leaf items and data
  btrfs: add eb to btrfs_node_key_ptr_offset
  btrfs: pass the extent buffer for the btrfs_item_nr helpers
  btrfs: move the csum helpers into ctree.h
  btrfs: move eb offset helpers into extent_io.h
  btrfs: move file_extent_item helpers into file-item.h
  btrfs: move leaf_data_end into ctree.c
  ...

1 files changed, 19 insertions, 6 deletions

diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index fab7eb76e53b..744a02b7fd67 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -7,6 +7,8 @@
 #include "btrfs_inode.h"
 #include "print-tree.h"
 #include "export.h"
+#include "accessors.h"
+#include "super.h"
 
 #define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, \
 						 parent_objectid) / 4)
@@ -57,9 +59,20 @@ static int btrfs_encode_fh(struct inode *inode, u32 *fh, int *max_len,
 	return type;
 }
 
+/*
+ * Read dentry of inode with @objectid from filesystem root @root_objectid.
+ *
+ * @sb:             the filesystem super block
+ * @objectid:       inode objectid
+ * @root_objectid:  object id of the subvolume root where to look up the inode
+ * @generation:     optional, if not zero, verify that the found inode
+ *                  generation matches
+ *
+ * Return dentry alias for the inode, otherwise an error. In case the
+ * generation does not match return ESTALE.
+ */
 struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
-				u64 root_objectid, u64 generation,
-				int check_generation)
+				u64 root_objectid, u64 generation)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 	struct btrfs_root *root;
@@ -77,7 +90,7 @@ struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
 	if (IS_ERR(inode))
 		return ERR_CAST(inode);
 
-	if (check_generation && generation != inode->i_generation) {
+	if (generation != 0 && generation != inode->i_generation) {
 		iput(inode);
 		return ERR_PTR(-ESTALE);
 	}
@@ -106,7 +119,7 @@ static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
 	objectid = fid->parent_objectid;
 	generation = fid->parent_gen;
 
-	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
+	return btrfs_get_dentry(sb, objectid, root_objectid, generation);
 }
 
 static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
@@ -128,7 +141,7 @@ static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
 	root_objectid = fid->root_objectid;
 	generation = fid->gen;
 
-	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
+	return btrfs_get_dentry(sb, objectid, root_objectid, generation);
 }
 
 struct dentry *btrfs_get_parent(struct dentry *child)
@@ -188,7 +201,7 @@ struct dentry *btrfs_get_parent(struct dentry *child)
 
 	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
 		return btrfs_get_dentry(fs_info->sb, key.objectid,
-					found_key.offset, 0, 0);
+					found_key.offset, 0);
 	}
 
 	return d_obtain_alias(btrfs_iget(fs_info->sb, key.objectid, root));