From a1a2c409b666befc58c2db9c7fbddf200f153470 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Thu, 27 Mar 2008 13:06:24 +0100 Subject: [patch 5/7] vfs: mountinfo: allow using process root Allow /proc//mountinfo to use the root of to calculate mountpoints. - move definition of 'struct proc_mounts' to - add the process's namespace and root to this structure - pass a pointer to 'struct proc_mounts' into seq_operations In addition the following cleanups are made: - use a common open function for /proc//{mounts,mountstat} - surround namespace.c part of these proc files with #ifdef CONFIG_PROC_FS - make the seq_operations structures const Signed-off-by: Miklos Szeredi Signed-off-by: Al Viro --- fs/proc/base.c | 108 +++++++++++++++++++++++++++------------------------------ 1 file changed, 51 insertions(+), 57 deletions(-) (limited to 'fs/proc/base.c') diff --git a/fs/proc/base.c b/fs/proc/base.c index 7313c62e3e9d..a04b3db7a296 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -502,17 +502,14 @@ static const struct inode_operations proc_def_inode_operations = { .setattr = proc_setattr, }; -extern const struct seq_operations mounts_op; -struct proc_mounts { - struct seq_file m; - int event; -}; - -static int mounts_open(struct inode *inode, struct file *file) +static int mounts_open_common(struct inode *inode, struct file *file, + const struct seq_operations *op) { struct task_struct *task = get_proc_task(inode); struct nsproxy *nsp; struct mnt_namespace *ns = NULL; + struct fs_struct *fs = NULL; + struct path root; struct proc_mounts *p; int ret = -EINVAL; @@ -525,40 +522,61 @@ static int mounts_open(struct inode *inode, struct file *file) get_mnt_ns(ns); } rcu_read_unlock(); - + if (ns) + fs = get_fs_struct(task); put_task_struct(task); } - if (ns) { - ret = -ENOMEM; - p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); - if (p) { - file->private_data = &p->m; - ret = seq_open(file, &mounts_op); - if (!ret) { - p->m.private = ns; - p->event = ns->event; - return 0; - } - kfree(p); - } - put_mnt_ns(ns); - } + if (!ns) + goto err; + if (!fs) + goto err_put_ns; + + read_lock(&fs->lock); + root = fs->root; + path_get(&root); + read_unlock(&fs->lock); + put_fs_struct(fs); + + ret = -ENOMEM; + p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); + if (!p) + goto err_put_path; + + file->private_data = &p->m; + ret = seq_open(file, op); + if (ret) + goto err_free; + + p->m.private = p; + p->ns = ns; + p->root = root; + p->event = ns->event; + + return 0; + + err_free: + kfree(p); + err_put_path: + path_put(&root); + err_put_ns: + put_mnt_ns(ns); + err: return ret; } static int mounts_release(struct inode *inode, struct file *file) { - struct seq_file *m = file->private_data; - struct mnt_namespace *ns = m->private; - put_mnt_ns(ns); + struct proc_mounts *p = file->private_data; + path_put(&p->root); + put_mnt_ns(p->ns); return seq_release(inode, file); } static unsigned mounts_poll(struct file *file, poll_table *wait) { struct proc_mounts *p = file->private_data; - struct mnt_namespace *ns = p->m.private; + struct mnt_namespace *ns = p->ns; unsigned res = 0; poll_wait(file, &ns->poll, wait); @@ -573,6 +591,11 @@ static unsigned mounts_poll(struct file *file, poll_table *wait) return res; } +static int mounts_open(struct inode *inode, struct file *file) +{ + return mounts_open_common(inode, file, &mounts_op); +} + static const struct file_operations proc_mounts_operations = { .open = mounts_open, .read = seq_read, @@ -581,38 +604,9 @@ static const struct file_operations proc_mounts_operations = { .poll = mounts_poll, }; -extern const struct seq_operations mountstats_op; static int mountstats_open(struct inode *inode, struct file *file) { - int ret = seq_open(file, &mountstats_op); - - if (!ret) { - struct seq_file *m = file->private_data; - struct nsproxy *nsp; - struct mnt_namespace *mnt_ns = NULL; - struct task_struct *task = get_proc_task(inode); - - if (task) { - rcu_read_lock(); - nsp = task_nsproxy(task); - if (nsp) { - mnt_ns = nsp->mnt_ns; - if (mnt_ns) - get_mnt_ns(mnt_ns); - } - rcu_read_unlock(); - - put_task_struct(task); - } - - if (mnt_ns) - m->private = mnt_ns; - else { - seq_release(inode, file); - ret = -EINVAL; - } - } - return ret; + return mounts_open_common(inode, file, &mountstats_op); } static const struct file_operations proc_mountstats_operations = { -- cgit v1.2.1 From 2d4d4864ac08caff5c204a752bd004eed4f08760 Mon Sep 17 00:00:00 2001 From: Ram Pai Date: Thu, 27 Mar 2008 13:06:25 +0100 Subject: [patch 6/7] vfs: mountinfo: add /proc//mountinfo [mszeredi@suse.cz] rewrite and split big patch into managable chunks /proc/mounts in its current form lacks important information: - propagation state - root of mount for bind mounts - the st_dev value used within the filesystem - identifier for each mount and it's parent It also suffers from the following problems: - not easily extendable - ambiguity of mountpoints within a chrooted environment - doesn't distinguish between filesystem dependent and independent options - doesn't distinguish between per mount and per super block options This patch introduces /proc//mountinfo which attempts to address all these deficiencies. Code shared between /proc//mounts and /proc//mountinfo is extracted into separate functions. Thanks to Al Viro for the help in getting the design right. Signed-off-by: Ram Pai Signed-off-by: Miklos Szeredi Signed-off-by: Al Viro --- fs/proc/base.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'fs/proc/base.c') diff --git a/fs/proc/base.c b/fs/proc/base.c index a04b3db7a296..c5e412a00b17 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -604,6 +604,19 @@ static const struct file_operations proc_mounts_operations = { .poll = mounts_poll, }; +static int mountinfo_open(struct inode *inode, struct file *file) +{ + return mounts_open_common(inode, file, &mountinfo_op); +} + +static const struct file_operations proc_mountinfo_operations = { + .open = mountinfo_open, + .read = seq_read, + .llseek = seq_lseek, + .release = mounts_release, + .poll = mounts_poll, +}; + static int mountstats_open(struct inode *inode, struct file *file) { return mounts_open_common(inode, file, &mountstats_op); @@ -2303,6 +2316,7 @@ static const struct pid_entry tgid_base_stuff[] = { LNK("root", root), LNK("exe", exe), REG("mounts", S_IRUGO, mounts), + REG("mountinfo", S_IRUGO, mountinfo), REG("mountstats", S_IRUSR, mountstats), #ifdef CONFIG_PROC_PAGE_MONITOR REG("clear_refs", S_IWUSR, clear_refs), @@ -2635,6 +2649,7 @@ static const struct pid_entry tid_base_stuff[] = { LNK("root", root), LNK("exe", exe), REG("mounts", S_IRUGO, mounts), + REG("mountinfo", S_IRUGO, mountinfo), #ifdef CONFIG_PROC_PAGE_MONITOR REG("clear_refs", S_IWUSR, clear_refs), REG("smaps", S_IRUGO, smaps), -- cgit v1.2.1