From e9c5a770dd4fa58dec03a7fde04a5fd7677dc6ad Mon Sep 17 00:00:00 2001 From: Cyrill Gorcunov Date: Sun, 26 Aug 2012 18:28:20 +0400 Subject: [PATCH] procfs: Convert /proc/pid/fdinfo/ handling routines to seq-file v2 This patch converts /proc/pid/fdinfo/ handling routines to seq-file which is needed to extend seq operations and plug in auxiliary fdinfo provides from subsystems like eventfd/eventpoll/fsnotify. Note the proc_fd_link no longer call for proc_fd_info, simply because the guts of proc_fd_info() got merged into ->show() of that seq_file Signed-off-by: Al Viro --- fs/proc/fd.c | 112 +++++++++++++++++++++++++++++---------------------- 1 file changed, 64 insertions(+), 48 deletions(-) diff --git a/fs/proc/fd.c b/fs/proc/fd.c index 1b0f932b4bd9..9cef449c0f76 100644 --- a/fs/proc/fd.c +++ b/fs/proc/fd.c @@ -6,61 +6,68 @@ #include #include #include +#include +#include #include #include "internal.h" #include "fd.h" -#define PROC_FDINFO_MAX 64 - -static int proc_fd_info(struct inode *inode, struct path *path, char *info) +static int seq_show(struct seq_file *m, void *v) { - struct task_struct *task = get_proc_task(inode); struct files_struct *files = NULL; - int fd = proc_fd(inode); - struct file *file; + int f_flags = 0, ret = -ENOENT; + struct file *file = NULL; + struct task_struct *task; + + task = get_proc_task(m->private); + if (!task) + return -ENOENT; + + files = get_files_struct(task); + put_task_struct(task); - if (task) { - files = get_files_struct(task); - put_task_struct(task); - } if (files) { - /* - * We are not taking a ref to the file structure, so we must - * hold ->file_lock. - */ + int fd = proc_fd(m->private); + spin_lock(&files->file_lock); file = fcheck_files(files, fd); if (file) { - unsigned int f_flags; - struct fdtable *fdt; + struct fdtable *fdt = files_fdtable(files); - fdt = files_fdtable(files); f_flags = file->f_flags & ~O_CLOEXEC; if (close_on_exec(fd, fdt)) f_flags |= O_CLOEXEC; - if (path) { - *path = file->f_path; - path_get(&file->f_path); - } - if (info) - snprintf(info, PROC_FDINFO_MAX, - "pos:\t%lli\n" - "flags:\t0%o\n", - (long long) file->f_pos, - f_flags); - spin_unlock(&files->file_lock); - put_files_struct(files); - return 0; + get_file(file); + ret = 0; } spin_unlock(&files->file_lock); put_files_struct(files); } - return -ENOENT; + + if (!ret) { + seq_printf(m, "pos:\t%lli\nflags:\t0%o\n", + (long long)file->f_pos, f_flags); + fput(file); + } + + return ret; } +static int seq_fdinfo_open(struct inode *inode, struct file *file) +{ + return single_open(file, seq_show, inode); +} + +static const struct file_operations proc_fdinfo_file_operations = { + .open = seq_fdinfo_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags) { struct files_struct *files; @@ -130,7 +137,32 @@ static const struct dentry_operations tid_fd_dentry_operations = { static int proc_fd_link(struct dentry *dentry, struct path *path) { - return proc_fd_info(dentry->d_inode, path, NULL); + struct files_struct *files = NULL; + struct task_struct *task; + int ret = -ENOENT; + + task = get_proc_task(dentry->d_inode); + if (task) { + files = get_files_struct(task); + put_task_struct(task); + } + + if (files) { + int fd = proc_fd(dentry->d_inode); + struct file *fd_file; + + spin_lock(&files->file_lock); + fd_file = fcheck_files(files, fd); + if (fd_file) { + *path = fd_file->f_path; + path_get(&fd_file->f_path); + ret = 0; + } + spin_unlock(&files->file_lock); + put_files_struct(files); + } + + return ret; } static struct dentry * @@ -245,22 +277,6 @@ out_no_task: return retval; } -static ssize_t proc_fdinfo_read(struct file *file, char __user *buf, - size_t len, loff_t *ppos) -{ - char tmp[PROC_FDINFO_MAX]; - int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp); - if (!err) - err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp)); - return err; -} - -static const struct file_operations proc_fdinfo_file_operations = { - .open = nonseekable_open, - .read = proc_fdinfo_read, - .llseek = no_llseek, -}; - static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir) { return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate); -- 2.39.5