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author | Eric W. Biederman <ebiederm@xmission.com> | 2010-07-10 21:52:49 (GMT) |
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committer | Eric W. Biederman <ebiederm@xmission.com> | 2012-11-19 11:09:34 (GMT) |
commit | e656d8a6f7fdf7612d2f5771f0ddfca9487f59d9 (patch) | |
tree | 66479ae4b636517e0e54e78b4ec95acadd0aec7a /fs/proc/base.c | |
parent | dd34ad35c32bb3d16789d8d4084aead7e68a7b09 (diff) | |
download | linux-fsl-qoriq-e656d8a6f7fdf7612d2f5771f0ddfca9487f59d9.tar.xz |
procfs: Use the proc generic infrastructure for proc/self.
I had visions at one point of splitting proc into two filesystems. If
that had happened proc/self being the the part of proc that actually deals
with pids would have been a nice cleanup. As it is proc/self requires
a lot of unnecessary infrastructure for a single file.
The only user visible change is that a mounted /proc for a pid namespace
that is dead now shows a broken proc symlink, instead of being completely
invisible. I don't think anyone will notice or care.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'fs/proc/base.c')
-rw-r--r-- | fs/proc/base.c | 154 |
1 files changed, 2 insertions, 152 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 144a967..cbe454e 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2237,146 +2237,6 @@ static const struct file_operations proc_coredump_filter_operations = { }; #endif -/* - * /proc/self: - */ -static int proc_self_readlink(struct dentry *dentry, char __user *buffer, - int buflen) -{ - struct pid_namespace *ns = dentry->d_sb->s_fs_info; - pid_t tgid = task_tgid_nr_ns(current, ns); - char tmp[PROC_NUMBUF]; - if (!tgid) - return -ENOENT; - sprintf(tmp, "%d", tgid); - return vfs_readlink(dentry,buffer,buflen,tmp); -} - -static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) -{ - struct pid_namespace *ns = dentry->d_sb->s_fs_info; - pid_t tgid = task_tgid_nr_ns(current, ns); - char *name = ERR_PTR(-ENOENT); - if (tgid) { - /* 11 for max length of signed int in decimal + NULL term */ - name = kmalloc(12, GFP_KERNEL); - if (!name) - name = ERR_PTR(-ENOMEM); - else - sprintf(name, "%d", tgid); - } - nd_set_link(nd, name); - return NULL; -} - -static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd, - void *cookie) -{ - char *s = nd_get_link(nd); - if (!IS_ERR(s)) - kfree(s); -} - -static const struct inode_operations proc_self_inode_operations = { - .readlink = proc_self_readlink, - .follow_link = proc_self_follow_link, - .put_link = proc_self_put_link, -}; - -/* - * proc base - * - * These are the directory entries in the root directory of /proc - * that properly belong to the /proc filesystem, as they describe - * describe something that is process related. - */ -static const struct pid_entry proc_base_stuff[] = { - NOD("self", S_IFLNK|S_IRWXUGO, - &proc_self_inode_operations, NULL, {}), -}; - -static struct dentry *proc_base_instantiate(struct inode *dir, - struct dentry *dentry, struct task_struct *task, const void *ptr) -{ - const struct pid_entry *p = ptr; - struct inode *inode; - struct proc_inode *ei; - struct dentry *error; - - /* Allocate the inode */ - error = ERR_PTR(-ENOMEM); - inode = new_inode(dir->i_sb); - if (!inode) - goto out; - - /* Initialize the inode */ - ei = PROC_I(inode); - inode->i_ino = get_next_ino(); - inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; - - /* - * grab the reference to the task. - */ - ei->pid = get_task_pid(task, PIDTYPE_PID); - if (!ei->pid) - goto out_iput; - - inode->i_mode = p->mode; - if (S_ISDIR(inode->i_mode)) - set_nlink(inode, 2); - if (S_ISLNK(inode->i_mode)) - inode->i_size = 64; - if (p->iop) - inode->i_op = p->iop; - if (p->fop) - inode->i_fop = p->fop; - ei->op = p->op; - d_add(dentry, inode); - error = NULL; -out: - return error; -out_iput: - iput(inode); - goto out; -} - -static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) -{ - struct dentry *error; - struct task_struct *task = get_proc_task(dir); - const struct pid_entry *p, *last; - - error = ERR_PTR(-ENOENT); - - if (!task) - goto out_no_task; - - /* Lookup the directory entry */ - last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1]; - for (p = proc_base_stuff; p <= last; p++) { - if (p->len != dentry->d_name.len) - continue; - if (!memcmp(dentry->d_name.name, p->name, p->len)) - break; - } - if (p > last) - goto out; - - error = proc_base_instantiate(dir, dentry, task, p); - -out: - put_task_struct(task); -out_no_task: - return error; -} - -static int proc_base_fill_cache(struct file *filp, void *dirent, - filldir_t filldir, struct task_struct *task, const struct pid_entry *p) -{ - return proc_fill_cache(filp, dirent, filldir, p->name, p->len, - proc_base_instantiate, task, p); -} - #ifdef CONFIG_TASK_IO_ACCOUNTING static int do_io_accounting(struct task_struct *task, char *buffer, int whole) { @@ -2767,15 +2627,11 @@ out: struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) { - struct dentry *result; + struct dentry *result = NULL; struct task_struct *task; unsigned tgid; struct pid_namespace *ns; - result = proc_base_lookup(dir, dentry); - if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) - goto out; - tgid = name_to_int(dentry); if (tgid == ~0U) goto out; @@ -2838,7 +2694,7 @@ retry: return iter; } -#define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff)) +#define TGID_OFFSET (FIRST_PROCESS_ENTRY) static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir, struct tgid_iter iter) @@ -2872,12 +2728,6 @@ int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) if (!reaper) goto out_no_task; - for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) { - const struct pid_entry *p = &proc_base_stuff[nr]; - if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0) - goto out; - } - ns = filp->f_dentry->d_sb->s_fs_info; iter.task = NULL; iter.tgid = filp->f_pos - TGID_OFFSET; |