linux-ext4 - [PATCH] mke2fs.8: Improve valid block size documentation

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Date:   Wed, 16 Dec 2020 11:22:06 +0100
From:   Jan Kara <jack@...e.cz>
To:     Ted Tso <tytso@....edu>
Cc:     <linux-ext4@...r.kernel.org>, Jan Kara <jack@...e.cz>
Subject: [PATCH] mke2fs.8: Improve valid block size documentation

Explain which valid block sizes mke2fs supports in more detail.

Reviewed-by: Andreas Dilger <adilger@...ger.ca>
Signed-off-by: Jan Kara <jack@...e.cz>
---
 misc/mke2fs.8.in | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/misc/mke2fs.8.in b/misc/mke2fs.8.in
index e6bfc6d6fd2d..171315b142bc 100644
--- a/misc/mke2fs.8.in
+++ b/misc/mke2fs.8.in
@@ -207,12 +207,14 @@ manual page for more details.
 .SH OPTIONS
 .TP
 .BI \-b " block-size"
-Specify the size of blocks in bytes.  Valid block-size values are 1024,
-2048 and 4096 bytes per block.  If omitted,
-block-size is heuristically determined by the filesystem size and
+Specify the size of blocks in bytes.  Valid block-size values are powers of two
+from 1024 up to 65536 (however note that the kernel is able to mount only
+filesystems with block-size smaller or equal to the system page size - 4k on
+x86 systems, upto 64k on ppc64 or aarch64 depending on kernel configuration).
+If omitted, block-size is heuristically determined by the filesystem size and
 the expected usage of the filesystem (see the
 .B \-T
-option).  If
+option).  In most common cases, the default block size is 4k. If
 .I block-size
 is preceded by a negative sign ('-'), then
 .B mke2fs
-- 
2.16.4