Merge tag 'perf-core-for-mingo-5.4-20190814' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo:

Intel PT:

  Adrian Hunter:

  - Add PEBS via Intel PT support, the kernel bits went via PeterZ.

perf record:

  Alexander Shishkin:

  - Add an option to take an AUX snapshot on exit.

  Tan Xiaojun:

  - Support aarch64 random socket_id assignment, just like was fixed for S/390.

tools:

  Andy Shevchenko:

  - Keep list of tools in alphabetical order on 'make -C tools help'.

perf session:

  Arnaldo Carvalho de Melo:

  - Avoid infinite loop when seeing invalid header.size, reported by
    Vince Weaver using a perf.data fuzzer.

Documentation:

  Vince Weaver:

  - Clarify HEADER_SAMPLE_TOPOLOGY format in the perf.data spec.

perf config:

  Arnaldo Carvalho de Melo:

  - Honour $PERF_CONFIG env var to specify alternate .perfconfig.

perf test:

  Arnaldo Carvalho de Melo:

  - Disable ~/.perfconfig to get default output in 'perf trace' tests.

perf top:

  Arnaldo Carvalho de Melo:

  - Set display thread COMM to help with debugging.

  - Collapse and resort evsels in a group, so that we have output
    similar to 'perf report' when using event groups, i.e.

      perf top -e '{cycles,instructions}'

    Will have two columns, and the instructions one will work.

core:

  Igor Lubashev:

  - Detect if libcap development files are available so that we
    can use capabilities to match the checks made by the kernel instead
    of using plain (geteuid() == 0).

Intel:

  Haiyan Song:

  - Add Icelake V1.00 event file.

perf trace:

  Leo Yan:

  - Fix segmentation fault when access syscall info on arm64.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 15 insertions, 62 deletions

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 69b59bf75882..c3c0c064c25d 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -6322,68 +6322,21 @@ static int changed_extent(struct send_ctx *sctx,
 {
 	int ret = 0;
 
-	if (sctx->cur_ino != sctx->cmp_key->objectid) {
-
-		if (result == BTRFS_COMPARE_TREE_CHANGED) {
-			struct extent_buffer *leaf_l;
-			struct extent_buffer *leaf_r;
-			struct btrfs_file_extent_item *ei_l;
-			struct btrfs_file_extent_item *ei_r;
-
-			leaf_l = sctx->left_path->nodes[0];
-			leaf_r = sctx->right_path->nodes[0];
-			ei_l = btrfs_item_ptr(leaf_l,
-					      sctx->left_path->slots[0],
-					      struct btrfs_file_extent_item);
-			ei_r = btrfs_item_ptr(leaf_r,
-					      sctx->right_path->slots[0],
-					      struct btrfs_file_extent_item);
-
-			/*
-			 * We may have found an extent item that has changed
-			 * only its disk_bytenr field and the corresponding
-			 * inode item was not updated. This case happens due to
-			 * very specific timings during relocation when a leaf
-			 * that contains file extent items is COWed while
-			 * relocation is ongoing and its in the stage where it
-			 * updates data pointers. So when this happens we can
-			 * safely ignore it since we know it's the same extent,
-			 * but just at different logical and physical locations
-			 * (when an extent is fully replaced with a new one, we
-			 * know the generation number must have changed too,
-			 * since snapshot creation implies committing the current
-			 * transaction, and the inode item must have been updated
-			 * as well).
-			 * This replacement of the disk_bytenr happens at
-			 * relocation.c:replace_file_extents() through
-			 * relocation.c:btrfs_reloc_cow_block().
-			 */
-			if (btrfs_file_extent_generation(leaf_l, ei_l) ==
-			    btrfs_file_extent_generation(leaf_r, ei_r) &&
-			    btrfs_file_extent_ram_bytes(leaf_l, ei_l) ==
-			    btrfs_file_extent_ram_bytes(leaf_r, ei_r) &&
-			    btrfs_file_extent_compression(leaf_l, ei_l) ==
-			    btrfs_file_extent_compression(leaf_r, ei_r) &&
-			    btrfs_file_extent_encryption(leaf_l, ei_l) ==
-			    btrfs_file_extent_encryption(leaf_r, ei_r) &&
-			    btrfs_file_extent_other_encoding(leaf_l, ei_l) ==
-			    btrfs_file_extent_other_encoding(leaf_r, ei_r) &&
-			    btrfs_file_extent_type(leaf_l, ei_l) ==
-			    btrfs_file_extent_type(leaf_r, ei_r) &&
-			    btrfs_file_extent_disk_bytenr(leaf_l, ei_l) !=
-			    btrfs_file_extent_disk_bytenr(leaf_r, ei_r) &&
-			    btrfs_file_extent_disk_num_bytes(leaf_l, ei_l) ==
-			    btrfs_file_extent_disk_num_bytes(leaf_r, ei_r) &&
-			    btrfs_file_extent_offset(leaf_l, ei_l) ==
-			    btrfs_file_extent_offset(leaf_r, ei_r) &&
-			    btrfs_file_extent_num_bytes(leaf_l, ei_l) ==
-			    btrfs_file_extent_num_bytes(leaf_r, ei_r))
-				return 0;
-		}
-
-		inconsistent_snapshot_error(sctx, result, "extent");
-		return -EIO;
-	}
+	/*
+	 * We have found an extent item that changed without the inode item
+	 * having changed. This can happen either after relocation (where the
+	 * disk_bytenr of an extent item is replaced at
+	 * relocation.c:replace_file_extents()) or after deduplication into a
+	 * file in both the parent and send snapshots (where an extent item can
+	 * get modified or replaced with a new one). Note that deduplication
+	 * updates the inode item, but it only changes the iversion (sequence
+	 * field in the inode item) of the inode, so if a file is deduplicated
+	 * the same amount of times in both the parent and send snapshots, its
+	 * iversion becames the same in both snapshots, whence the inode item is
+	 * the same on both snapshots.
+	 */
+	if (sctx->cur_ino != sctx->cmp_key->objectid)
+		return 0;
 
 	if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
 		if (result != BTRFS_COMPARE_TREE_DELETED)