btrfs-progs: docs: fix incorrect description about compression with O…

…_DIRECT It was reported in https://lore.kernel.org/linux-btrfs/[email protected]/ that compression does not happen on direct io files. This is incorrectly documented that it works but this is not true. Compression works on buffered writes and relies on page cache, while direct io avoids that and takes a different path in code. [ci skip] Pull-request: #764 Author: HAN Yuwei <[email protected]> Signed-off-by: David Sterba <[email protected]>
kdave · Mar 25, 2024 · f240b9f · f240b9f
1 parent 41dce59
commit f240b9f
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/Documentation/ch-compression.rst b/Documentation/ch-compression.rst
@@ -145,9 +145,9 @@ Compatibility
 -------------
 
 Compression is done using the COW mechanism so it's incompatible with
-*nodatacow*. Direct IO works on compressed files but will fall back to buffered
-writes and leads to recompression. Currently *nodatasum* and compression don't
-work together.
+*nodatacow*. Direct IO read works on compressed files but will fall back to
+buffered writes and leads to no compression even if force compression is set.
+Currently *nodatasum* and compression don't work together.
 
 The compression algorithms have been added over time so the version
 compatibility should be also considered, together with other tools that may