Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs update from Al Viro:

 - big one - consolidation of descriptor-related logics; almost all of
   that is moved to fs/file.c

   (BTW, I'm seriously tempted to rename the result to fd.c.  As it is,
   we have a situation when file_table.c is about handling of struct
   file and file.c is about handling of descriptor tables; the reasons
   are historical - file_table.c used to be about a static array of
   struct file we used to have way back).

   A lot of stray ends got cleaned up and converted to saner primitives,
   disgusting mess in android/binder.c is still disgusting, but at least
   doesn't poke so much in descriptor table guts anymore.  A bunch of
   relatively minor races got fixed in process, plus an ext4 struct file
   leak.

 - related thing - fget_light() partially unuglified; see fdget() in
   there (and yes, it generates the code as good as we used to have).

 - also related - bits of Cyrill's procfs stuff that got entangled into
   that work; _not_ all of it, just the initial move to fs/proc/fd.c and
   switch of fdinfo to seq_file.

 - Alex's fs/coredump.c spiltoff - the same story, had been easier to
   take that commit than mess with conflicts.  The rest is a separate
   pile, this was just a mechanical code movement.

 - a few misc patches all over the place.  Not all for this cycle,
   there'll be more (and quite a few currently sit in akpm's tree)."

Fix up trivial conflicts in the android binder driver, and some fairly
simple conflicts due to two different changes to the sock_alloc_file()
interface ("take descriptor handling from sock_alloc_file() to callers"
vs "net: Providing protocol type via system.sockprotoname xattr of
/proc/PID/fd entries" adding a dentry name to the socket)

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits)
  MAX_LFS_FILESIZE should be a loff_t
  compat: fs: Generic compat_sys_sendfile implementation
  fs: push rcu_barrier() from deactivate_locked_super() to filesystems
  btrfs: reada_extent doesn't need kref for refcount
  coredump: move core dump functionality into its own file
  coredump: prevent double-free on an error path in core dumper
  usb/gadget: fix misannotations
  fcntl: fix misannotations
  ceph: don't abuse d_delete() on failure exits
  hypfs: ->d_parent is never NULL or negative
  vfs: delete surplus inode NULL check
  switch simple cases of fget_light to fdget
  new helpers: fdget()/fdput()
  switch o2hb_region_dev_write() to fget_light()
  proc_map_files_readdir(): don't bother with grabbing files
  make get_file() return its argument
  vhost_set_vring(): turn pollstart/pollstop into bool
  switch prctl_set_mm_exe_file() to fget_light()
  switch xfs_find_handle() to fget_light()
  switch xfs_swapext() to fget_light()
  ...

1 files changed, 11 insertions, 406 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index acd1960c28a2..d295af993677 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -90,6 +90,7 @@
 #endif
 #include <trace/events/oom.h>
 #include "internal.h"
+#include "fd.h"
 
 /* NOTE:
  *      Implementing inode permission operations in /proc is almost
@@ -136,8 +137,6 @@ struct pid_entry {
                 NULL, &proc_single_file_operations,     \
                 { .proc_show = show } )
 
-static int proc_fd_permission(struct inode *inode, int mask);
-
 /*
  * Count the number of hardlinks for the pid_entry table, excluding the .
  * and .. links.
@@ -1500,7 +1499,7 @@ out:
         return error;
 }
 
-static const struct inode_operations proc_pid_link_inode_operations = {
+const struct inode_operations proc_pid_link_inode_operations = {
         .readlink       = proc_pid_readlink,
         .follow_link    = proc_pid_follow_link,
         .setattr        = proc_setattr,
@@ -1509,21 +1508,6 @@ static const struct inode_operations proc_pid_link_inode_operations = {
 
 /* building an inode */
 
-static int task_dumpable(struct task_struct *task)
-{
-        int dumpable = 0;
-        struct mm_struct *mm;
-
-        task_lock(task);
-        mm = task->mm;
-        if (mm)
-                dumpable = get_dumpable(mm);
-        task_unlock(task);
-        if(dumpable == 1)
-                return 1;
-        return 0;
-}
-
 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
 {
         struct inode * inode;
@@ -1649,15 +1633,6 @@ int pid_revalidate(struct dentry *dentry, unsigned int flags)
         return 0;
 }
 
-static int pid_delete_dentry(const struct dentry * dentry)
-{
-        /* Is the task we represent dead?
-         * If so, then don't put the dentry on the lru list,
-         * kill it immediately.
-         */
-        return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
-}
-
 const struct dentry_operations pid_dentry_operations =
 {
         .d_revalidate   = pid_revalidate,
@@ -1720,289 +1695,6 @@ end_instantiate:
         return filldir(dirent, name, len, filp->f_pos, ino, type);
 }
 
-static unsigned name_to_int(struct dentry *dentry)
-{
-        const char *name = dentry->d_name.name;
-        int len = dentry->d_name.len;
-        unsigned n = 0;
-
-        if (len > 1 && *name == '0')
-                goto out;
-        while (len-- > 0) {
-                unsigned c = *name++ - '0';
-                if (c > 9)
-                        goto out;
-                if (n >= (~0U-9)/10)
-                        goto out;
-                n *= 10;
-                n += c;
-        }
-        return n;
-out:
-        return ~0U;
-}
-
-#define PROC_FDINFO_MAX 64
-
-static int proc_fd_info(struct inode *inode, struct path *path, char *info)
-{
-        struct task_struct *task = get_proc_task(inode);
-        struct files_struct *files = NULL;
-        struct file *file;
-        int fd = proc_fd(inode);
-
-        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.
-                 */
-                spin_lock(&files->file_lock);
-                file = fcheck_files(files, fd);
-                if (file) {
-                        unsigned int f_flags;
-                        struct fdtable *fdt;
-
-                        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;
-                }
-                spin_unlock(&files->file_lock);
-                put_files_struct(files);
-        }
-        return -ENOENT;
-}
-
-static int proc_fd_link(struct dentry *dentry, struct path *path)
-{
-        return proc_fd_info(dentry->d_inode, path, NULL);
-}
-
-static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
-{
-        struct inode *inode;
-        struct task_struct *task;
-        int fd;
-        struct files_struct *files;
-        const struct cred *cred;
-
-        if (flags & LOOKUP_RCU)
-                return -ECHILD;
-
-        inode = dentry->d_inode;
-        task = get_proc_task(inode);
-        fd = proc_fd(inode);
-
-        if (task) {
-                files = get_files_struct(task);
-                if (files) {
-                        struct file *file;
-                        rcu_read_lock();
-                        file = fcheck_files(files, fd);
-                        if (file) {
-                                unsigned f_mode = file->f_mode;
-
-                                rcu_read_unlock();
-                                put_files_struct(files);
-
-                                if (task_dumpable(task)) {
-                                        rcu_read_lock();
-                                        cred = __task_cred(task);
-                                        inode->i_uid = cred->euid;
-                                        inode->i_gid = cred->egid;
-                                        rcu_read_unlock();
-                                } else {
-                                        inode->i_uid = GLOBAL_ROOT_UID;
-                                        inode->i_gid = GLOBAL_ROOT_GID;
-                                }
-
-                                if (S_ISLNK(inode->i_mode)) {
-                                        unsigned i_mode = S_IFLNK;
-                                        if (f_mode & FMODE_READ)
-                                                i_mode |= S_IRUSR | S_IXUSR;
-                                        if (f_mode & FMODE_WRITE)
-                                                i_mode |= S_IWUSR | S_IXUSR;
-                                        inode->i_mode = i_mode;
-                                }
-
-                                security_task_to_inode(task, inode);
-                                put_task_struct(task);
-                                return 1;
-                        }
-                        rcu_read_unlock();
-                        put_files_struct(files);
-                }
-                put_task_struct(task);
-        }
-        d_drop(dentry);
-        return 0;
-}
-
-static const struct dentry_operations tid_fd_dentry_operations =
-{
-        .d_revalidate   = tid_fd_revalidate,
-        .d_delete       = pid_delete_dentry,
-};
-
-static struct dentry *proc_fd_instantiate(struct inode *dir,
-        struct dentry *dentry, struct task_struct *task, const void *ptr)
-{
-        unsigned fd = (unsigned long)ptr;
-        struct inode *inode;
-        struct proc_inode *ei;
-        struct dentry *error = ERR_PTR(-ENOENT);
-
-        inode = proc_pid_make_inode(dir->i_sb, task);
-        if (!inode)
-                goto out;
-        ei = PROC_I(inode);
-        ei->fd = fd;
-
-        inode->i_mode = S_IFLNK;
-        inode->i_op = &proc_pid_link_inode_operations;
-        inode->i_size = 64;
-        ei->op.proc_get_link = proc_fd_link;
-        d_set_d_op(dentry, &tid_fd_dentry_operations);
-        d_add(dentry, inode);
-        /* Close the race of the process dying before we return the dentry */
-        if (tid_fd_revalidate(dentry, 0))
-                error = NULL;
-
- out:
-        return error;
-}
-
-static struct dentry *proc_lookupfd_common(struct inode *dir,
-                                           struct dentry *dentry,
-                                           instantiate_t instantiate)
-{
-        struct task_struct *task = get_proc_task(dir);
-        unsigned fd = name_to_int(dentry);
-        struct dentry *result = ERR_PTR(-ENOENT);
-
-        if (!task)
-                goto out_no_task;
-        if (fd == ~0U)
-                goto out;
-
-        result = instantiate(dir, dentry, task, (void *)(unsigned long)fd);
-out:
-        put_task_struct(task);
-out_no_task:
-        return result;
-}
-
-static int proc_readfd_common(struct file * filp, void * dirent,
-                              filldir_t filldir, instantiate_t instantiate)
-{
-        struct dentry *dentry = filp->f_path.dentry;
-        struct inode *inode = dentry->d_inode;
-        struct task_struct *p = get_proc_task(inode);
-        unsigned int fd, ino;
-        int retval;
-        struct files_struct * files;
-
-        retval = -ENOENT;
-        if (!p)
-                goto out_no_task;
-        retval = 0;
-
-        fd = filp->f_pos;
-        switch (fd) {
-                case 0:
-                        if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
-                                goto out;
-                        filp->f_pos++;
-                case 1:
-                        ino = parent_ino(dentry);
-                        if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
-                                goto out;
-                        filp->f_pos++;
-                default:
-                        files = get_files_struct(p);
-                        if (!files)
-                                goto out;
-                        rcu_read_lock();
-                        for (fd = filp->f_pos-2;
-                             fd < files_fdtable(files)->max_fds;
-                             fd++, filp->f_pos++) {
-                                char name[PROC_NUMBUF];
-                                int len;
-                                int rv;
-
-                                if (!fcheck_files(files, fd))
-                                        continue;
-                                rcu_read_unlock();
-
-                                len = snprintf(name, sizeof(name), "%d", fd);
-                                rv = proc_fill_cache(filp, dirent, filldir,
-                                                     name, len, instantiate, p,
-                                                     (void *)(unsigned long)fd);
-                                if (rv < 0)
-                                        goto out_fd_loop;
-                                rcu_read_lock();
-                        }
-                        rcu_read_unlock();
-out_fd_loop:
-                        put_files_struct(files);
-        }
-out:
-        put_task_struct(p);
-out_no_task:
-        return retval;
-}
-
-static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
-                                    unsigned int flags)
-{
-        return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
-}
-
-static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
-{
-        return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
-}
-
-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 const struct file_operations proc_fd_operations = {
-        .read           = generic_read_dir,
-        .readdir        = proc_readfd,
-        .llseek         = default_llseek,
-};
-
 #ifdef CONFIG_CHECKPOINT_RESTORE
 
 /*
@@ -2121,7 +1813,7 @@ out:
 }
 
 struct map_files_info {
-        struct file     *file;
+        fmode_t         mode;
         unsigned long   len;
         unsigned char   name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
 };
@@ -2130,13 +1822,10 @@ static struct dentry *
 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
                            struct task_struct *task, const void *ptr)
 {
-        const struct file *file = ptr;
+        fmode_t mode = (fmode_t)(unsigned long)ptr;
         struct proc_inode *ei;
         struct inode *inode;
 
-        if (!file)
-                return ERR_PTR(-ENOENT);
-
         inode = proc_pid_make_inode(dir->i_sb, task);
         if (!inode)
                 return ERR_PTR(-ENOENT);
@@ -2148,9 +1837,9 @@ proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
         inode->i_size = 64;
         inode->i_mode = S_IFLNK;
 
-        if (file->f_mode & FMODE_READ)
+        if (mode & FMODE_READ)
                 inode->i_mode |= S_IRUSR;
-        if (file->f_mode & FMODE_WRITE)
+        if (mode & FMODE_WRITE)
                 inode->i_mode |= S_IWUSR;
 
         d_set_d_op(dentry, &tid_map_files_dentry_operations);
@@ -2194,7 +1883,8 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
         if (!vma)
                 goto out_no_vma;
 
-        result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file);
+        result = proc_map_files_instantiate(dir, dentry, task,
+                        (void *)(unsigned long)vma->vm_file->f_mode);
 
 out_no_vma:
         up_read(&mm->mmap_sem);
@@ -2295,8 +1985,7 @@ proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
                                 if (++pos <= filp->f_pos)
                                         continue;
 
-                                get_file(vma->vm_file);
-                                info.file = vma->vm_file;
+                                info.mode = vma->vm_file->f_mode;
                                 info.len = snprintf(info.name,
                                                 sizeof(info.name), "%lx-%lx",
                                                 vma->vm_start, vma->vm_end);
@@ -2311,19 +2000,11 @@ proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
                         ret = proc_fill_cache(filp, dirent, filldir,
                                               p->name, p->len,
                                               proc_map_files_instantiate,
-                                              task, p->file);
+                                              task,
+                                              (void *)(unsigned long)p->mode);
                         if (ret)
                                 break;
                         filp->f_pos++;
-                        fput(p->file);
-                }
-                for (; i < nr_files; i++) {
-                        /*
-                         * In case of error don't forget
-                         * to put rest of file refs.
-                         */
-                        p = flex_array_get(fa, i);
-                        fput(p->file);
                 }
                 if (fa)
                         flex_array_free(fa);
@@ -2345,82 +2026,6 @@ static const struct file_operations proc_map_files_operations = {
 
 #endif /* CONFIG_CHECKPOINT_RESTORE */
 
-/*
- * /proc/pid/fd needs a special permission handler so that a process can still
- * access /proc/self/fd after it has executed a setuid().
- */
-static int proc_fd_permission(struct inode *inode, int mask)
-{
-        int rv = generic_permission(inode, mask);
-        if (rv == 0)
-                return 0;
-        if (task_pid(current) == proc_pid(inode))
-                rv = 0;
-        return rv;
-}
-
-/*
- * proc directories can do almost nothing..
- */
-static const struct inode_operations proc_fd_inode_operations = {
-        .lookup         = proc_lookupfd,
-        .permission     = proc_fd_permission,
-        .setattr        = proc_setattr,
-};
-
-static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
-        struct dentry *dentry, struct task_struct *task, const void *ptr)
-{
-        unsigned fd = (unsigned long)ptr;
-        struct inode *inode;
-        struct proc_inode *ei;
-        struct dentry *error = ERR_PTR(-ENOENT);
-
-        inode = proc_pid_make_inode(dir->i_sb, task);
-        if (!inode)
-                goto out;
-        ei = PROC_I(inode);
-        ei->fd = fd;
-        inode->i_mode = S_IFREG | S_IRUSR;
-        inode->i_fop = &proc_fdinfo_file_operations;
-        d_set_d_op(dentry, &tid_fd_dentry_operations);
-        d_add(dentry, inode);
-        /* Close the race of the process dying before we return the dentry */
-        if (tid_fd_revalidate(dentry, 0))
-                error = NULL;
-
- out:
-        return error;
-}
-
-static struct dentry *proc_lookupfdinfo(struct inode *dir,
-                                        struct dentry *dentry,
-                                        unsigned int flags)
-{
-        return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
-}
-
-static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
-{
-        return proc_readfd_common(filp, dirent, filldir,
-                                  proc_fdinfo_instantiate);
-}
-
-static const struct file_operations proc_fdinfo_operations = {
-        .read           = generic_read_dir,
-        .readdir        = proc_readfdinfo,
-        .llseek         = default_llseek,
-};
-
-/*
- * proc directories can do almost nothing..
- */
-static const struct inode_operations proc_fdinfo_inode_operations = {
-        .lookup         = proc_lookupfdinfo,
-        .setattr        = proc_setattr,
-};
-
-
 static struct dentry *proc_pident_instantiate(struct inode *dir,
         struct dentry *dentry, struct task_struct *task, const void *ptr)
 {