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From: Alexander Viro <viro@math.psu.edu>
To: Linus Torvalds <torvalds@transmeta.com>
Subject: [CFT][PATCH] (4/5) sane procfs/dcache interaction
Date: Sat, 20 Apr 2002 13:58:09 -0400 (EDT)
Cc: linux-kernel@vger.kernel.org
diff -urN C8-retain_dentry/fs/proc/base.c C8-current/fs/proc/base.c
--- C8-retain_dentry/fs/proc/base.c Fri Apr 19 01:17:36 2002
+++ C8-current/fs/proc/base.c Fri Apr 19 01:39:23 2002
@@ -37,6 +37,52 @@
#define fake_ino(pid,ino) (((pid)<<16)|(ino))
+enum pid_directory_inos {
+ PROC_PID_INO = 2,
+ PROC_PID_STATUS,
+ PROC_PID_MEM,
+ PROC_PID_CWD,
+ PROC_PID_ROOT,
+ PROC_PID_EXE,
+ PROC_PID_FD,
+ PROC_PID_ENVIRON,
+ PROC_PID_CMDLINE,
+ PROC_PID_STAT,
+ PROC_PID_STATM,
+ PROC_PID_MAPS,
+ PROC_PID_CPU,
+ PROC_PID_MOUNTS,
+ PROC_PID_FD_DIR = 0x8000, /* 0x8000-0xffff */
+};
+
+struct pid_entry {
+ int type;
+ int len;
+ char *name;
+ mode_t mode;
+};
+
+#define E(type,name,mode) {(type),sizeof(name)-1,(name),(mode)}
+static struct pid_entry base_stuff[] = {
+ E(PROC_PID_FD, "fd", S_IFDIR|S_IRUSR|S_IXUSR),
+ E(PROC_PID_ENVIRON, "environ", S_IFREG|S_IRUSR),
+ E(PROC_PID_STATUS, "status", S_IFREG|S_IRUGO),
+ E(PROC_PID_CMDLINE, "cmdline", S_IFREG|S_IRUGO),
+ E(PROC_PID_STAT, "stat", S_IFREG|S_IRUGO),
+ E(PROC_PID_STATM, "statm", S_IFREG|S_IRUGO),
+#ifdef CONFIG_SMP
+ E(PROC_PID_CPU, "cpu", S_IFREG|S_IRUGO),
+#endif
+ E(PROC_PID_MAPS, "maps", S_IFREG|S_IRUGO),
+ E(PROC_PID_MEM, "mem", S_IFREG|S_IRUSR|S_IWUSR),
+ E(PROC_PID_CWD, "cwd", S_IFLNK|S_IRWXUGO),
+ E(PROC_PID_ROOT, "root", S_IFLNK|S_IRWXUGO),
+ E(PROC_PID_EXE, "exe", S_IFLNK|S_IRWXUGO),
+ E(PROC_PID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
+ {0,0,NULL,0}
+};
+#undef E
+
static inline struct task_struct *proc_task(struct inode *inode)
{
return PROC_I(inode)->task;
@@ -50,11 +96,28 @@
static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
- struct file *file = PROC_I(inode)->file;
- if (file) {
- *mnt = mntget(file->f_vfsmnt);
- *dentry = dget(file->f_dentry);
- return 0;
+ struct task_struct *task = proc_task(inode);
+ struct files_struct *files;
+ struct file *file;
+ int fd = (inode->i_ino & 0xffff) - PROC_PID_FD_DIR;
+
+ task_lock(task);
+ files = task->files;
+ if (files)
+ atomic_inc(&files->count);
+ task_unlock(task);
+ if (files) {
+ read_lock(&files->file_lock);
+ file = fcheck_files(files, fd);
+ if (file) {
+ *mnt = mntget(file->f_vfsmnt);
+ *dentry = dget(file->f_dentry);
+ read_unlock(&files->file_lock);
+ put_files_struct(files);
+ return 0;
+ }
+ read_unlock(&files->file_lock);
+ put_files_struct(files);
}
return -ENOENT;
}
@@ -525,52 +588,6 @@
follow_link: proc_pid_follow_link
};
-struct pid_entry {
- int type;
- int len;
- char *name;
- mode_t mode;
-};
-
-enum pid_directory_inos {
- PROC_PID_INO = 2,
- PROC_PID_STATUS,
- PROC_PID_MEM,
- PROC_PID_CWD,
- PROC_PID_ROOT,
- PROC_PID_EXE,
- PROC_PID_FD,
- PROC_PID_ENVIRON,
- PROC_PID_CMDLINE,
- PROC_PID_STAT,
- PROC_PID_STATM,
- PROC_PID_MAPS,
- PROC_PID_CPU,
- PROC_PID_MOUNTS,
- PROC_PID_FD_DIR = 0x8000, /* 0x8000-0xffff */
-};
-
-#define E(type,name,mode) {(type),sizeof(name)-1,(name),(mode)}
-static struct pid_entry base_stuff[] = {
- E(PROC_PID_FD, "fd", S_IFDIR|S_IRUSR|S_IXUSR),
- E(PROC_PID_ENVIRON, "environ", S_IFREG|S_IRUSR),
- E(PROC_PID_STATUS, "status", S_IFREG|S_IRUGO),
- E(PROC_PID_CMDLINE, "cmdline", S_IFREG|S_IRUGO),
- E(PROC_PID_STAT, "stat", S_IFREG|S_IRUGO),
- E(PROC_PID_STATM, "statm", S_IFREG|S_IRUGO),
-#ifdef CONFIG_SMP
- E(PROC_PID_CPU, "cpu", S_IFREG|S_IRUGO),
-#endif
- E(PROC_PID_MAPS, "maps", S_IFREG|S_IRUGO),
- E(PROC_PID_MEM, "mem", S_IFREG|S_IRUSR|S_IWUSR),
- E(PROC_PID_CWD, "cwd", S_IFLNK|S_IRWXUGO),
- E(PROC_PID_ROOT, "root", S_IFLNK|S_IRWXUGO),
- E(PROC_PID_EXE, "exe", S_IFLNK|S_IRWXUGO),
- E(PROC_PID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
- {0,0,NULL,0}
-};
-#undef E
-
#define NUMBUF 10
static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
@@ -707,7 +724,6 @@
/* Common stuff */
ei = PROC_I(inode);
ei->task = NULL;
- ei->file = NULL;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode->i_ino = fake_ino(task->pid, ino);
@@ -842,21 +858,20 @@
task_unlock(task);
if (!files)
goto out_unlock;
+ inode->i_mode = S_IFLNK;
read_lock(&files->file_lock);
- file = ei->file = fcheck_files(files, fd);
+ file = fcheck_files(files, fd);
if (!file)
goto out_unlock2;
- get_file(file);
+ if (file->f_mode & 1)
+ inode->i_mode |= S_IRUSR | S_IXUSR;
+ if (file->f_mode & 2)
+ inode->i_mode |= S_IWUSR | S_IXUSR;
read_unlock(&files->file_lock);
put_files_struct(files);
inode->i_op = &proc_pid_link_inode_operations;
inode->i_size = 64;
- inode->i_mode = S_IFLNK;
ei->op.proc_get_link = proc_fd_link;
- if (file->f_mode & 1)
- inode->i_mode |= S_IRUSR | S_IXUSR;
- if (file->f_mode & 2)
- inode->i_mode |= S_IWUSR | S_IXUSR;
dentry->d_op = &pid_fd_dentry_operations;
d_add(dentry, inode);
if (!proc_task(dentry->d_inode)->pid)
@@ -1078,8 +1093,6 @@
void proc_pid_delete_inode(struct inode *inode)
{
- if (PROC_I(inode)->file)
- fput(PROC_I(inode)->file);
if (proc_task(inode))
put_task_struct(proc_task(inode));
}
diff -urN C8-retain_dentry/include/linux/proc_fs.h C8-current/include/linux/proc_fs.h
--- C8-retain_dentry/include/linux/proc_fs.h Sun Apr 14 17:53:12 2002
+++ C8-current/include/linux/proc_fs.h Fri Apr 19 01:33:23 2002
@@ -212,7 +212,6 @@
int (*proc_get_link)(struct inode *, struct dentry **, struct vfsmount **);
int (*proc_read)(struct task_struct *task, char *page);
} op;
- struct file *file;
struct proc_dir_entry *pde;
struct inode vfs_inode;
};
-
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