From 97412950b10e64f347aec4a9b759395c2465adf6 Mon Sep 17 00:00:00 2001 From: Vasiliy Kulikov Date: Tue, 10 Jan 2012 15:11:27 -0800 Subject: [PATCH] procfs: parse mount options Add support for procfs mount options. Actual mount options are coming in the next patches. Signed-off-by: Vasiliy Kulikov Cc: Alexey Dobriyan Cc: Al Viro Cc: Randy Dunlap Cc: "H. Peter Anvin" Cc: Greg KH Cc: Theodore Tso Cc: Alan Cox Cc: James Morris Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/inode.c | 10 +++++++++ fs/proc/internal.h | 1 + fs/proc/root.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 64 insertions(+), 2 deletions(-) diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 51a1766..27c762f 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -17,7 +18,9 @@ #include #include #include +#include #include +#include #include #include @@ -101,12 +104,19 @@ void __init proc_init_inodecache(void) init_once); } +static int proc_show_options(struct seq_file *seq, struct dentry *root) +{ + return 0; +} + static const struct super_operations proc_sops = { .alloc_inode = proc_alloc_inode, .destroy_inode = proc_destroy_inode, .drop_inode = generic_delete_inode, .evict_inode = proc_evict_inode, .statfs = simple_statfs, + .remount_fs = proc_remount, + .show_options = proc_show_options, }; static void __pde_users_dec(struct proc_dir_entry *pde) diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 7838e5c..2925775 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -117,6 +117,7 @@ void pde_put(struct proc_dir_entry *pde); int proc_fill_super(struct super_block *); struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *); +int proc_remount(struct super_block *sb, int *flags, char *data); /* * These are generic /proc routines that use the internal diff --git a/fs/proc/root.c b/fs/proc/root.c index 03102d9..6a8ac1d 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "internal.h" @@ -36,6 +37,48 @@ static int proc_set_super(struct super_block *sb, void *data) return err; } +enum { + Opt_err, +}; + +static const match_table_t tokens = { + {Opt_err, NULL}, +}; + +static int proc_parse_options(char *options, struct pid_namespace *pid) +{ + char *p; + substring_t args[MAX_OPT_ARGS]; + + pr_debug("proc: options = %s\n", options); + + if (!options) + return 1; + + while ((p = strsep(&options, ",")) != NULL) { + int token; + if (!*p) + continue; + + args[0].to = args[0].from = 0; + token = match_token(p, tokens, args); + switch (token) { + default: + pr_err("proc: unrecognized mount option \"%s\" " + "or missing value\n", p); + return 0; + } + } + + return 1; +} + +int proc_remount(struct super_block *sb, int *flags, char *data) +{ + struct pid_namespace *pid = sb->s_fs_info; + return !proc_parse_options(data, pid); +} + static struct dentry *proc_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { @@ -43,11 +86,15 @@ static struct dentry *proc_mount(struct file_system_type *fs_type, struct super_block *sb; struct pid_namespace *ns; struct proc_inode *ei; + char *options; - if (flags & MS_KERNMOUNT) + if (flags & MS_KERNMOUNT) { ns = (struct pid_namespace *)data; - else + options = NULL; + } else { ns = current->nsproxy->pid_ns; + options = data; + } sb = sget(fs_type, proc_test_super, proc_set_super, ns); if (IS_ERR(sb)) @@ -55,6 +102,10 @@ static struct dentry *proc_mount(struct file_system_type *fs_type, if (!sb->s_root) { sb->s_flags = flags; + if (!proc_parse_options(options, ns)) { + deactivate_locked_super(sb); + return ERR_PTR(-EINVAL); + } err = proc_fill_super(sb); if (err) { deactivate_locked_super(sb); -- 1.7.7.5