The patch titled Subject: autofs: add strictexpire mount option has been added to the -mm tree. Its filename is autofs-add-strictexpire-mount-option.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/autofs-add-strictexpire-mount-option.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/autofs-add-strictexpire-mount-option.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Ian Kent <raven@xxxxxxxxxx> Subject: autofs: add strictexpire mount option 092a53452b (("autofs: take more care to not update last_used on path walk") helped to (partially) resolve a problem where automounts were not expiring due to aggressive accesses from user space. This patch was later reverted because, for very large environments, it meant more mount requests from clients and when there are a lot of clients this caused a fairly significant increase in server load. But there is a need for both types of expire check, depending on use case, so add a mount option to allow for strict update of last use of autofs dentrys (which just means not updating the last use on path walk access). Link: http://lkml.kernel.org/r/154296973880.9889.14085372741514507967.stgit@pluto-themaw-net Signed-off-by: Ian Kent <raven@xxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- --- a/fs/autofs/autofs_i.h~autofs-add-strictexpire-mount-option +++ a/fs/autofs/autofs_i.h @@ -104,6 +104,7 @@ struct autofs_wait_queue { #define AUTOFS_SBI_MAGIC 0x6d4a556d #define AUTOFS_SBI_CATATONIC 0x0001 +#define AUTOFS_SBI_STRICTEXPIRE 0x0002 struct autofs_sb_info { u32 magic; --- a/fs/autofs/inode.c~autofs-add-strictexpire-mount-option +++ a/fs/autofs/inode.c @@ -87,6 +87,8 @@ static int autofs_show_options(struct se seq_printf(m, ",direct"); else seq_printf(m, ",indirect"); + if (sbi->flags & AUTOFS_SBI_STRICTEXPIRE) + seq_printf(m, ",strictexpire"); #ifdef CONFIG_CHECKPOINT_RESTORE if (sbi->pipe) seq_printf(m, ",pipe_ino=%ld", file_inode(sbi->pipe)->i_ino); @@ -109,7 +111,7 @@ static const struct super_operations aut }; enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto, - Opt_indirect, Opt_direct, Opt_offset}; + Opt_indirect, Opt_direct, Opt_offset, Opt_strictexpire}; static const match_table_t tokens = { {Opt_fd, "fd=%u"}, @@ -121,6 +123,7 @@ static const match_table_t tokens = { {Opt_indirect, "indirect"}, {Opt_direct, "direct"}, {Opt_offset, "offset"}, + {Opt_strictexpire, "strictexpire"}, {Opt_err, NULL} }; @@ -200,6 +203,9 @@ static int parse_options(char *options, case Opt_offset: set_autofs_type_offset(&sbi->type); break; + case Opt_strictexpire: + sbi->flags |= AUTOFS_SBI_STRICTEXPIRE; + break; default: return 1; } --- a/fs/autofs/root.c~autofs-add-strictexpire-mount-option +++ a/fs/autofs/root.c @@ -275,8 +275,11 @@ static int autofs_mount_wait(const struc pr_debug("waiting for mount name=%pd\n", path->dentry); status = autofs_wait(sbi, path, NFY_MOUNT); pr_debug("mount wait done status=%d\n", status); + ino->last_used = jiffies; + return status; } - ino->last_used = jiffies; + if (!(sbi->flags & AUTOFS_SBI_STRICTEXPIRE)) + ino->last_used = jiffies; return status; } --- a/include/uapi/linux/auto_fs.h~autofs-add-strictexpire-mount-option +++ a/include/uapi/linux/auto_fs.h @@ -23,7 +23,7 @@ #define AUTOFS_MIN_PROTO_VERSION 3 #define AUTOFS_MAX_PROTO_VERSION 5 -#define AUTOFS_PROTO_SUBVERSION 3 +#define AUTOFS_PROTO_SUBVERSION 4 /* * The wait_queue_token (autofs_wqt_t) is part of a structure which is passed _ Patches currently in -mm which might be from raven@xxxxxxxxxx are autofs-improve-ioctl-sbi-checks.patch autofs-fix-possible-inode-leak-in-autofs_fill_super.patch autofs-simplify-parse_options-function-call.patch autofs-change-catatonic-setting-to-a-bit-flag.patch autofs-add-strictexpire-mount-option.patch