From 1dfc82a14ed538992f5c37a152995e93ede10469 Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Wed, 24 Feb 2021 09:57:18 -0800 Subject: [PATCH] Linux: increase max nvlist_src size On Linux increase the maximum allowed size of the src nvlist which can be passed to the /dev/zfs ioctl. Originally, this was set to a maximum of KMALLOC_MAX_SIZE (4M) because it was kmalloc'd. Since that time it's been converted to a vmalloc so that's no longer a hard limit, and it's desirable for `zfs send/recv` to allow larger nvlists so more snapshots can be sent at once. Signed-off-by: Brian Behlendorf Closes #6572 Closes #11638 --- man/man5/zfs-module-parameters.5 | 2 +- module/os/linux/zfs/zfs_ioctl_os.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5 index 8fec44dd37..d68e85fa07 100644 --- a/man/man5/zfs-module-parameters.5 +++ b/man/man5/zfs-module-parameters.5 @@ -1238,7 +1238,7 @@ amount of memory. When the limit is exceeded, the ioctl fails with EINVAL and a description of the error is sent to the zfs-dbgmsg log. This parameter should not need to be touched under normal circumstances. On FreeBSD, the default is based on the system limit on user wired memory. On Linux, the default is -\fBKMALLOC_MAX_SIZE\fR . +\fB128MB\fR. .sp Default value: \fB0\fR (kernel decides) .RE diff --git a/module/os/linux/zfs/zfs_ioctl_os.c b/module/os/linux/zfs/zfs_ioctl_os.c index b88e0497d0..6f5cff1770 100644 --- a/module/os/linux/zfs/zfs_ioctl_os.c +++ b/module/os/linux/zfs/zfs_ioctl_os.c @@ -209,7 +209,7 @@ zfs_max_nvlist_src_size_os(void) if (zfs_max_nvlist_src_size != 0) return (zfs_max_nvlist_src_size); - return (KMALLOC_MAX_SIZE); + return (MIN(ptob(zfs_totalram_pages) / 4, 128 * 1024 * 1024)); } void