btrfs-progs: docs: add linux 6.3 changes

Signed-off-by: David Sterba <dsterba@suse.com>

Documentation/Contributors.rst

@@ -31,6 +31,7 @@ Statistics for 6.x series
     "6.0", "24", "109726", "156988", "192", "+4248 -3108"
     "6.1", "28", "110850", "159284", "224", "+7738 -5442"
     "6.2", "23", "111898", "161197", "289", "+11693 -9780"
+    "6.3", "19", "111615", "160912", "150", "+2824 -3108"
 
 Statistics for 5.x series
 -------------------------

Documentation/Feature-by-version.rst

@@ -527,3 +527,23 @@ features see [[Status]] page.
         Devices that support trim/discard will enable the asynchronous discard
         for the whole filesystem.
 
+6.3 - discard=async settings tuned
+        The default IOPS limit has changed from 100 to 1000 and writing value 0
+        to '/sys/fs/btrfs/FSID/discard/iops_limit' newly means to not do any
+        throttling.
+
+6.3 - block group allocation class heuristics
+        Pack files by size (up to 128k, up to 8M, more) to avoid fragmentation
+        in block groups, assuming that file size and life time is correlated,
+        in particular this may help during balance. The stats about the number
+        of used classes per block group type is exported in
+        '/sys/fs/btrfs/FSID/allocation/\*/size_classes'.
+
+6.3 - in DEV_INFO ioctl export per-device FSID
+        A seeding device could have a different FSID, available in syfs and now
+        available via DEV_INFO ioctl.
+
+6.3 - send utimes cache, reduced stream size
+        Utimes for directories are emitted into the send steram only when
+        finalizing the directory, the cache also gains significant speedups (up
+        to 10x).

Documentation/Kernel-by-version.rst

@@ -219,8 +219,8 @@ Fixes:
   loop device is reformatted and the entry gets stale
 - limit number of send clones by maximum memory allocated
 
-6.3 (? 2023)
-^^^^^^^^^^^^
+6.3 (Apr 2023)
+^^^^^^^^^^^^^^
 
 Features: