9388dbf231
Resolves: rhbz#2182361 Resolves: rhbz#2161936 Resolves: rhbz#2160746 Signed-off-by: Pavel Reichl <preichl@redhat.com>
79 lines
2.9 KiB
Diff
79 lines
2.9 KiB
Diff
From 5ca4d781d36946de197ed2d4196c84c8f6b4522f Mon Sep 17 00:00:00 2001
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From: Ian Kent <raven@themaw.net>
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Date: Mon, 12 Oct 2020 15:40:01 -0400
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Subject: [PATCH] xfsprogs: ignore autofs mount table entries
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Some of the xfsprogs utilities read the mount table via. getmntent(3).
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The mount table may contain (almost always these days since /etc/mtab is
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symlinked to /proc/self/mounts) autofs mount entries. During processing
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of the mount table entries statfs(2) can be called on mount point paths
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which will trigger an automount if those entries are direct or offset
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autofs mount triggers (indirect autofs mounts aren't affected).
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This can be a problem when there are a lot of autofs direct or offset
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mounts because real mounts will be triggered when statfs(2) is called.
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This can be particularly bad if the triggered mounts are NFS mounts and
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the server is unavailable leading to lengthy boot times or worse.
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Simply ignoring autofs mount entries during getmentent(3) traversals
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avoids the statfs() call that triggers these mounts. If there are
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automounted mounts (real mounts) at the time of reading the mount table
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these will still be seen in the list so they will be included if that
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actually matters to the reader.
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Recent glibc getmntent(3) can ignore autofs mounts but that requires the
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autofs user to configure autofs to use the "ignore" pseudo mount option
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for autofs mounts. But this isn't yet the autofs default (to prevent
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unexpected side effects) so that can't be used.
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The autofs direct and offset automount triggers are pseudo file system
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mounts and are more or less useless in terms on file system information
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so excluding them doesn't sacrifice useful file system information
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either.
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Consequently excluding autofs mounts shouldn't have any adverse side
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effects.
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Changes since v1:
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- drop hunk from fsr/xfs_fsr.c.
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Signed-off-by: Ian Kent <raven@themaw.net>
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Reviewed-by: Eric Sandeen <sandeen@redhat.com>
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Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
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Signed-off-by: Pavel Reichl <preichl@redhat.com>
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---
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libfrog/linux.c | 2 ++
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libfrog/paths.c | 2 ++
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2 files changed, 4 insertions(+)
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diff --git a/libfrog/linux.c b/libfrog/linux.c
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index 40a839d1..a45d99ab 100644
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--- a/libfrog/linux.c
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+++ b/libfrog/linux.c
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@@ -73,6 +73,8 @@ platform_check_mount(char *name, char *block, struct stat *s, int flags)
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* servers. So first, a simple check: does the "dev" start with "/" ?
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*/
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while ((mnt = getmntent(f)) != NULL) {
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+ if (!strcmp(mnt->mnt_type, "autofs"))
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+ continue;
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if (mnt->mnt_fsname[0] != '/')
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continue;
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if (stat(mnt->mnt_dir, &mst) < 0)
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diff --git a/libfrog/paths.c b/libfrog/paths.c
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index 32737223..d6793764 100644
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--- a/libfrog/paths.c
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+++ b/libfrog/paths.c
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@@ -389,6 +389,8 @@ fs_table_initialise_mounts(
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return errno;
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while ((mnt = getmntent(mtp)) != NULL) {
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+ if (!strcmp(mnt->mnt_type, "autofs"))
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+ continue;
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if (!realpath(mnt->mnt_dir, rmnt_dir))
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continue;
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if (!realpath(mnt->mnt_fsname, rmnt_fsname))
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--
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2.40.1
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