diff mbox series

[6/6] autofs - add strictexpire mount option

Message ID 154207302780.11064.8291702401952765872.stgit@pluto-themaw-net (mailing list archive)
State New, archived
Headers show
Series [1/6] autofs - improve ioctl sbi checks | expand

Commit Message

Ian Kent Nov. 13, 2018, 1:37 a.m. UTC
Commit 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 accesses).

Signed-off-by: Ian Kent <raven@themaw.net>
---
 fs/autofs/autofs_i.h         |    1 +
 fs/autofs/inode.c            |   13 ++++++++++++-
 fs/autofs/root.c             |    5 ++++-
 include/uapi/linux/auto_fs.h |    2 +-
 4 files changed, 18 insertions(+), 3 deletions(-)

Comments

kernel test robot Nov. 15, 2018, 1:26 p.m. UTC | #1
Hi Ian,

I love your patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v4.20-rc2]
[cannot apply to next-20181115]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Ian-Kent/autofs-improve-ioctl-sbi-checks/20181114-021150
config: x86_64-allmodconfig (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All error/warnings (new ones prefixed by >>):

>> fs/autofs/init.c:19:25: warning: symbol 'autofs_fs_type' was not declared. Should it be static?
--
   include/linux/slab.h:332:43: warning: dubious: x & !y
   include/linux/slab.h:332:43: warning: dubious: x & !y
>> fs/autofs/inode.c:372:35: error: cannot dereference this type
   fs/autofs/inode.c:373:35: error: cannot dereference this type
>> fs/autofs/inode.c:372:35: warning: unknown expression (8 46)
   fs/autofs/inode.c:373:35: warning: unknown expression (8 46)
   fs/autofs/inode.c: In function 'autofs_fill_super':
   fs/autofs/inode.c:372:28: error: invalid type argument of '->' (have 'struct autofs_fs_params')
     root_inode->i_uid = params->uid;
                               ^~
   fs/autofs/inode.c:373:28: error: invalid type argument of '->' (have 'struct autofs_fs_params')
     root_inode->i_gid = params->gid;
                               ^~

vim +372 fs/autofs/inode.c

e35160168 Ian Kent 2018-11-13  324  
e35160168 Ian Kent 2018-11-13  325  int autofs_fill_super(struct super_block *s, void *data, int silent)
e35160168 Ian Kent 2018-11-13  326  {
e35160168 Ian Kent 2018-11-13  327  	struct inode *root_inode;
e35160168 Ian Kent 2018-11-13  328  	struct dentry *root;
f4507adde Ian Kent 2018-11-13  329  	struct autofs_fs_params params;
e35160168 Ian Kent 2018-11-13  330  	struct autofs_sb_info *sbi;
e35160168 Ian Kent 2018-11-13  331  	struct autofs_info *ino;
e35160168 Ian Kent 2018-11-13  332  	int ret = -EINVAL;
e35160168 Ian Kent 2018-11-13  333  
e35160168 Ian Kent 2018-11-13  334  	sbi = autofs_alloc_sbi(s);
e35160168 Ian Kent 2018-11-13  335  	if (!sbi)
e35160168 Ian Kent 2018-11-13  336  		return -ENOMEM;
e35160168 Ian Kent 2018-11-13  337  
e35160168 Ian Kent 2018-11-13  338  	pr_debug("starting up, sbi = %p\n", sbi);
e35160168 Ian Kent 2018-11-13  339  
e35160168 Ian Kent 2018-11-13  340  	s->s_fs_info = sbi;
ebc921ca9 Ian Kent 2018-06-07  341  	s->s_blocksize = 1024;
ebc921ca9 Ian Kent 2018-06-07  342  	s->s_blocksize_bits = 10;
ebc921ca9 Ian Kent 2018-06-07  343  	s->s_magic = AUTOFS_SUPER_MAGIC;
ebc921ca9 Ian Kent 2018-06-07  344  	s->s_op = &autofs_sops;
ebc921ca9 Ian Kent 2018-06-07  345  	s->s_d_op = &autofs_dentry_operations;
ebc921ca9 Ian Kent 2018-06-07  346  	s->s_time_gran = 1;
ebc921ca9 Ian Kent 2018-06-07  347  
ebc921ca9 Ian Kent 2018-06-07  348  	/*
ebc921ca9 Ian Kent 2018-06-07  349  	 * Get the root inode and dentry, but defer checking for errors.
ebc921ca9 Ian Kent 2018-06-07  350  	 */
ebc921ca9 Ian Kent 2018-06-07  351  	ino = autofs_new_ino(sbi);
ebc921ca9 Ian Kent 2018-06-07  352  	if (!ino) {
ebc921ca9 Ian Kent 2018-06-07  353  		ret = -ENOMEM;
ebc921ca9 Ian Kent 2018-06-07  354  		goto fail_free;
ebc921ca9 Ian Kent 2018-06-07  355  	}
ebc921ca9 Ian Kent 2018-06-07  356  	root_inode = autofs_get_inode(s, S_IFDIR | 0755);
eef302f31 Ian Kent 2018-11-13  357  	if (!root_inode) {
eef302f31 Ian Kent 2018-11-13  358  		ret = -ENOMEM;
eef302f31 Ian Kent 2018-11-13  359  		goto fail_ino;
eef302f31 Ian Kent 2018-11-13  360  	}
ebc921ca9 Ian Kent 2018-06-07  361  	root = d_make_root(root_inode);
ebc921ca9 Ian Kent 2018-06-07  362  	if (!root)
eef302f31 Ian Kent 2018-11-13  363  		goto fail_iput;
ebc921ca9 Ian Kent 2018-06-07  364  
ebc921ca9 Ian Kent 2018-06-07  365  	root->d_fsdata = ino;
ebc921ca9 Ian Kent 2018-06-07  366  
f4507adde Ian Kent 2018-11-13  367  	memset(&params, 0, sizeof(struct autofs_fs_params));
f4507adde Ian Kent 2018-11-13  368  	if (autofs_parse_options(data, &params)) {
ebc921ca9 Ian Kent 2018-06-07  369  		pr_err("called with bogus options\n");
ebc921ca9 Ian Kent 2018-06-07  370  		goto fail_dput;
ebc921ca9 Ian Kent 2018-06-07  371  	}
f4507adde Ian Kent 2018-11-13 @372  	root_inode->i_uid = params->uid;
f4507adde Ian Kent 2018-11-13  373  	root_inode->i_gid = params->gid;
ebc921ca9 Ian Kent 2018-06-07  374  
f4507adde Ian Kent 2018-11-13  375  	ret = autofs_apply_sbi_options(sbi, &params);
f4507adde Ian Kent 2018-11-13  376  	if (ret)
ebc921ca9 Ian Kent 2018-06-07  377  		goto fail_dput;
ebc921ca9 Ian Kent 2018-06-07  378  
ebc921ca9 Ian Kent 2018-06-07  379  	if (autofs_type_trigger(sbi->type))
ebc921ca9 Ian Kent 2018-06-07  380  		__managed_dentry_set_managed(root);
ebc921ca9 Ian Kent 2018-06-07  381  
ebc921ca9 Ian Kent 2018-06-07  382  	root_inode->i_fop = &autofs_root_operations;
ebc921ca9 Ian Kent 2018-06-07  383  	root_inode->i_op = &autofs_dir_inode_operations;
ebc921ca9 Ian Kent 2018-06-07  384  
ebc921ca9 Ian Kent 2018-06-07  385  	/*
ebc921ca9 Ian Kent 2018-06-07  386  	 * Success! Install the root dentry now to indicate completion.
ebc921ca9 Ian Kent 2018-06-07  387  	 */
ebc921ca9 Ian Kent 2018-06-07  388  	s->s_root = root;
ebc921ca9 Ian Kent 2018-06-07  389  	return 0;
ebc921ca9 Ian Kent 2018-06-07  390  
ebc921ca9 Ian Kent 2018-06-07  391  	/*
ebc921ca9 Ian Kent 2018-06-07  392  	 * Failure ... clean up.
ebc921ca9 Ian Kent 2018-06-07  393  	 */
ebc921ca9 Ian Kent 2018-06-07  394  fail_dput:
ebc921ca9 Ian Kent 2018-06-07  395  	dput(root);
ebc921ca9 Ian Kent 2018-06-07  396  	goto fail_free;
eef302f31 Ian Kent 2018-11-13  397  fail_iput:
eef302f31 Ian Kent 2018-11-13  398  	iput(root_inode);
ebc921ca9 Ian Kent 2018-06-07  399  fail_ino:
ebc921ca9 Ian Kent 2018-06-07  400  	autofs_free_ino(ino);
ebc921ca9 Ian Kent 2018-06-07  401  fail_free:
ebc921ca9 Ian Kent 2018-06-07  402  	kfree(sbi);
ebc921ca9 Ian Kent 2018-06-07  403  	s->s_fs_info = NULL;
ebc921ca9 Ian Kent 2018-06-07  404  	return ret;
ebc921ca9 Ian Kent 2018-06-07  405  }
ebc921ca9 Ian Kent 2018-06-07  406  

:::::: The code at line 372 was first introduced by commit
:::::: f4507adde6ebc94c273ccc2c18f2afb0fea20cf9 autofs - use struct for mount params

:::::: TO: Ian Kent <raven@themaw.net>
:::::: CC: 0day robot <lkp@intel.com>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
diff mbox series

Patch

diff --git a/fs/autofs/autofs_i.h b/fs/autofs/autofs_i.h
index 032cbb12531a..fa3733beb52e 100644
--- a/fs/autofs/autofs_i.h
+++ b/fs/autofs/autofs_i.h
@@ -102,6 +102,7 @@  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;
diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c
index 5e774852ae84..75d61f5a3069 100644
--- a/fs/autofs/inode.c
+++ b/fs/autofs/inode.c
@@ -87,6 +87,8 @@  static int autofs_show_options(struct seq_file *m, struct dentry *root)
 		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);
@@ -116,11 +118,12 @@  struct autofs_fs_params {
 	bool pgrp_set;
 	int min_proto;
 	int max_proto;
+	bool strictexpire;
 	unsigned int type;
 };
 
 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"},
@@ -132,6 +135,7 @@  static const match_table_t tokens = {
 	{Opt_indirect, "indirect"},
 	{Opt_direct, "direct"},
 	{Opt_offset, "offset"},
+	{Opt_strictexpire, "strictexpire"},
 	{Opt_err, NULL}
 };
 
@@ -155,6 +159,7 @@  static int autofs_parse_options(char *options, struct autofs_fs_params *params)
 	params->max_proto = AUTOFS_MAX_PROTO_VERSION;
 
 	params->pgrp_set = false;
+	params->strictexpire = false;
 
 	while ((p = strsep(&options, ",")) != NULL) {
 		int token;
@@ -210,6 +215,9 @@  static int autofs_parse_options(char *options, struct autofs_fs_params *params)
 		case Opt_offset:
 			set_autofs_type_offset(&params->type);
 			break;
+		case Opt_strictexpire:
+			params->strictexpire = true;
+			break;
 		default:
 			return 1;
 		}
@@ -275,6 +283,9 @@  static int autofs_apply_sbi_options(struct autofs_sb_info *sbi,
 	if (err < 0)
 		goto out_fput;
 
+	if (params->strictexpire)
+		sbi->flags |= AUTOFS_SBI_STRICTEXPIRE;
+
 	sbi->flags &= ~AUTOFS_SBI_CATATONIC;
 
 	return 0;
diff --git a/fs/autofs/root.c b/fs/autofs/root.c
index 164ccd3402cf..1246f396bf0e 100644
--- a/fs/autofs/root.c
+++ b/fs/autofs/root.c
@@ -275,8 +275,11 @@  static int autofs_mount_wait(const struct path *path, bool rcu_walk)
 		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;
 }
 
diff --git a/include/uapi/linux/auto_fs.h b/include/uapi/linux/auto_fs.h
index df31aa9c9a8c..082119630b49 100644
--- a/include/uapi/linux/auto_fs.h
+++ b/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