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[firefly-linux-kernel-4.4.55.git] / fs / file_table.c

diff --git a/fs/file_table.c b/fs/file_table.c
index a04bdd81c11ca3799d4429d8c5eb3579621e0628..01e4c1e8e6b6badc81a659a8616694dc677310a7 100644 (file)
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -60,7 +60,7 @@ static inline void file_free(struct file *f)
 /*
  * Return the total number of open files in the system
  */
-static int get_nr_files(void)
+static long get_nr_files(void)
 {
        return percpu_counter_read_positive(&nr_files);
 }
@@ -68,7 +68,7 @@ static int get_nr_files(void)
 /*
  * Return the maximum number of open files in the system
  */
-int get_max_files(void)
+unsigned long get_max_files(void)
 {
        return files_stat.max_files;
 }
@@ -82,7 +82,7 @@ int proc_nr_files(ctl_table *table, int write,
                      void __user *buffer, size_t *lenp, loff_t *ppos)
 {
        files_stat.nr_files = get_nr_files();
-       return proc_dointvec(table, write, buffer, lenp, ppos);
+       return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
 }
 #else
 int proc_nr_files(ctl_table *table, int write,
@@ -105,7 +105,7 @@ int proc_nr_files(ctl_table *table, int write,
 struct file *get_empty_filp(void)
 {
        const struct cred *cred = current_cred();
-       static int old_max;
+       static long old_max;
        struct file * f;
 
        /*
@@ -125,13 +125,13 @@ struct file *get_empty_filp(void)
                goto fail;
 
        percpu_counter_inc(&nr_files);
+       f->f_cred = get_cred(cred);
        if (security_file_alloc(f))
                goto fail_sec;
 
        INIT_LIST_HEAD(&f->f_u.fu_list);
        atomic_long_set(&f->f_count, 1);
        rwlock_init(&f->f_owner.lock);
-       f->f_cred = get_cred(cred);
        spin_lock_init(&f->f_lock);
        eventpoll_init_file(f);
        /* f->f_version: 0 */
@@ -140,8 +140,7 @@ struct file *get_empty_filp(void)
 over:
        /* Ran out of filps - report that */
        if (get_nr_files() > old_max) {
-               printk(KERN_INFO "VFS: file-max limit %d reached\n",
-                                       get_max_files());
+               pr_info("VFS: file-max limit %lu reached\n", get_max_files());
                old_max = get_nr_files();
        }
        goto fail;
@@ -191,7 +190,8 @@ struct file *alloc_file(struct path *path, fmode_t mode,
                file_take_write(file);
                WARN_ON(mnt_clone_write(path->mnt));
        }
-       ima_counts_get(file);
+       if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
+               i_readcount_inc(path->dentry->d_inode);
        return file;
 }
 EXPORT_SYMBOL(alloc_file);
@@ -247,11 +247,15 @@ static void __fput(struct file *file)
                file->f_op->release(inode, file);
        security_file_free(file);
        ima_file_free(file);
-       if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL))
+       if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL &&
+                    !(file->f_mode & FMODE_PATH))) {
                cdev_put(inode->i_cdev);
+       }
        fops_put(file->f_op);
        put_pid(file->f_owner.pid);
        file_sb_list_del(file);
+       if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
+               i_readcount_dec(inode);
        if (file->f_mode & FMODE_WRITE)
                drop_file_write_access(file);
        file->f_path.dentry = NULL;
@@ -277,11 +281,10 @@ struct file *fget(unsigned int fd)
        rcu_read_lock();
        file = fcheck_files(files, fd);
        if (file) {
-               if (!atomic_long_inc_not_zero(&file->f_count)) {
-                       /* File object ref couldn't be taken */
-                       rcu_read_unlock();
-                       return NULL;
-               }
+               /* File object ref couldn't be taken */
+               if (file->f_mode & FMODE_PATH ||
+                   !atomic_long_inc_not_zero(&file->f_count))
+                       file = NULL;
        }
        rcu_read_unlock();
 
@@ -290,6 +293,25 @@ struct file *fget(unsigned int fd)
 
 EXPORT_SYMBOL(fget);
 
+struct file *fget_raw(unsigned int fd)
+{
+       struct file *file;
+       struct files_struct *files = current->files;
+
+       rcu_read_lock();
+       file = fcheck_files(files, fd);
+       if (file) {
+               /* File object ref couldn't be taken */
+               if (!atomic_long_inc_not_zero(&file->f_count))
+                       file = NULL;
+       }
+       rcu_read_unlock();
+
+       return file;
+}
+
+EXPORT_SYMBOL(fget_raw);
+
 /*
  * Lightweight file lookup - no refcnt increment if fd table isn't shared.
  *
@@ -312,7 +334,34 @@ struct file *fget_light(unsigned int fd, int *fput_needed)
        struct files_struct *files = current->files;
 
        *fput_needed = 0;
-       if (likely((atomic_read(&files->count) == 1))) {
+       if (atomic_read(&files->count) == 1) {
+               file = fcheck_files(files, fd);
+               if (file && (file->f_mode & FMODE_PATH))
+                       file = NULL;
+       } else {
+               rcu_read_lock();
+               file = fcheck_files(files, fd);
+               if (file) {
+                       if (!(file->f_mode & FMODE_PATH) &&
+                           atomic_long_inc_not_zero(&file->f_count))
+                               *fput_needed = 1;
+                       else
+                               /* Didn't get the reference, someone's freed */
+                               file = NULL;
+               }
+               rcu_read_unlock();
+       }
+
+       return file;
+}
+
+struct file *fget_raw_light(unsigned int fd, int *fput_needed)
+{
+       struct file *file;
+       struct files_struct *files = current->files;
+
+       *fput_needed = 0;
+       if (atomic_read(&files->count) == 1) {
                file = fcheck_files(files, fd);
        } else {
                rcu_read_lock();
@@ -487,7 +536,7 @@ retry:
 
 void __init files_init(unsigned long mempages)
 { 
-       int n; 
+       unsigned long n;
 
        filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0,
                        SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
@@ -498,9 +547,7 @@ void __init files_init(unsigned long mempages)
         */ 
 
        n = (mempages * (PAGE_SIZE / 1024)) / 10;
-       files_stat.max_files = n; 
-       if (files_stat.max_files < NR_FILE)
-               files_stat.max_files = NR_FILE;
+       files_stat.max_files = max_t(unsigned long, n, NR_FILE);
        files_defer_init();
        lg_lock_init(files_lglock);
        percpu_counter_init(&nr_files, 0);