On Wed, Jan 13, 2021 at 04:04:30PM +0100, Christoph Hellwig wrote:

On Mon, Jan 11, 2021 at 03:23:40PM -0800, Darrick J. Wong wrote:

quoted

+ * 100ths of a second) with the exception of blockgc_timer, which is measured
+ * in seconds.
  */
 xfs_param_t xfs_params = {
 			  /*	MIN		DFLT		MAX	*/

@@ -28,8 +28,7 @@ xfs_param_t xfs_params = {
 	.rotorstep	= {	1,		1,		255	},
 	.inherit_nodfrg	= {	0,		1,		1	},
 	.fstrm_timer	= {	1,		30*100,		3600*100},
-	.eofb_timer	= {	1,		300,		3600*24},
-	.cowb_timer	= {	1,		1800,		3600*24},
+	.blockgc_timer	= {	1,		300,		3600*24},

Renaming this is going to break existing scripts.  We could either kill off the
COW timer as it is relatively recent, or we could keep both and use the minimum.
But removing both and picking an entirely new name seems a little dangerous.

"blockgc_timer" is the internal variable.  The xfs_sysctl.c changes at
the bottom of the patch erase speculative_cow_prealloc_lifetime, but the
older knob remains unchanged.  See xfs_sysctl.c:

	{
		.procname	= "speculative_prealloc_lifetime",
		.data		= &xfs_params.blockgc_timer.val,

And from the test system:

# ls /proc/sys/fs/xfs/
total 0
-rw-r--r-- 1 root root 0 Jan 13 15:46 error_level
-rw-r--r-- 1 root root 0 Jan 13 15:46 filestream_centisecs
-rw-r--r-- 1 root root 0 Jan 13 15:46 inherit_noatime
-rw-r--r-- 1 root root 0 Jan 13 15:46 inherit_nodefrag
-rw-r--r-- 1 root root 0 Jan 13 15:46 inherit_nodump
-rw-r--r-- 1 root root 0 Jan 13 15:46 inherit_nosymlinks
-rw-r--r-- 1 root root 0 Jan 13 15:46 inherit_sync
-rw-r--r-- 1 root root 0 Jan 13 15:46 irix_sgid_inherit
-rw-r--r-- 1 root root 0 Jan 13 15:46 irix_symlink_mode
-rw-r--r-- 1 root root 0 Jan 13 15:46 panic_mask
-rw-r--r-- 1 root root 0 Jan 13 15:46 rotorstep
-rw-r--r-- 1 root root 0 Jan 13 15:46 speculative_prealloc_lifetime
-rw-r--r-- 1 root root 0 Jan 13 15:46 stats_clear
-rw-r--r-- 1 root root 0 Jan 13 15:46 xfssyncd_centisecs

--D

Otherwise this looks sane to me.