From 41e55b476bcfc90f1ad81c02c5375367fdace9e9 Mon Sep 17 00:00:00 2001 From: siv0 Date: Tue, 31 Oct 2023 21:57:54 +0100 Subject: [PATCH] Fix nfs_truncate_shares without /etc/exports.d Calling nfs_reset_shares on Linux prints a warning: `failed to lock /etc/exports.d/zfs.exports.lock: No such file or directory` when /etc/exports.d does not exist. The directory gets created, when a filesystem is actually exported through nfs_toggle_share and nfs_init_share. The truncation of /etc/exports.d/zfs.exports happens unconditionally when calling `zfs mount -a` (via zfs_do_mount and share_mount in `cmd/zfs/zfs_main.c`). Fixing the issue only in the Linux part, since the exports file on freebsd is in `/etc/zfs/`, which seems present on 2 FreeBSD systems I have access to (through `/etc/zfs/compatibility.d/`), while a Debian box does not have the directory even if `/usr/sbin/exportfs` is present through the `nfs-kernel-server` package. The code for exports_available is copied from nfs_available above. Fixes: ede037cda73675f42b1452187e8dd3438fafc220 ("Make zfs-share service resilient to stale exports") Reviewed-by: Brian Atkinson Reviewed-by: Brian Behlendorf Signed-off-by: Stoiko Ivanov Closes #15369 Closes #15468 --- lib/libshare/os/linux/nfs.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/lib/libshare/os/linux/nfs.c b/lib/libshare/os/linux/nfs.c index 004946b0cfe4..3dce818400fc 100644 --- a/lib/libshare/os/linux/nfs.c +++ b/lib/libshare/os/linux/nfs.c @@ -47,6 +47,7 @@ static boolean_t nfs_available(void); +static boolean_t exports_available(void); typedef int (*nfs_shareopt_callback_t)(const char *opt, const char *value, void *cookie); @@ -539,6 +540,8 @@ nfs_commit_shares(void) static void nfs_truncate_shares(void) { + if (!exports_available()) + return; nfs_reset_shares(ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE); } @@ -566,3 +569,18 @@ nfs_available(void) return (avail == 1); } + +static boolean_t +exports_available(void) +{ + static int avail; + + if (!avail) { + if (access(ZFS_EXPORTS_DIR, F_OK) != 0) + avail = -1; + else + avail = 1; + } + + return (avail == 1); +}