4 files changed, 66 insertions, 10 deletions

diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 6d370622fdfe..8e36c7e3c345 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -1709,6 +1709,10 @@ A typical output is
         flags:  0100002
         mnt_id: 19
 
+All locks associated with a file descriptor are shown in its fdinfo too.
+
+lock:       1: FLOCK  ADVISORY  WRITE 359 00:13:11691 0 EOF
+
 The files such as eventfd, fsnotify, signalfd, epoll among the regular pos/flags
 pair provide additional information particular to the objects they represent.
 
diff --git a/fs/locks.c b/fs/locks.c
index 52b780fb5258..653faabb07f4 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -2590,6 +2590,44 @@ static int locks_show(struct seq_file *f, void *v)
         return 0;
 }
 
+static void __show_fd_locks(struct seq_file *f,
+                        struct list_head *head, int *id,
+                        struct file *filp, struct files_struct *files)
+{
+        struct file_lock *fl;
+
+        list_for_each_entry(fl, head, fl_list) {
+
+                if (filp != fl->fl_file)
+                        continue;
+                if (fl->fl_owner != files &&
+                    fl->fl_owner != filp)
+                        continue;
+
+                (*id)++;
+                seq_puts(f, "lock:\t");
+                lock_get_status(f, fl, *id, "");
+        }
+}
+
+void show_fd_locks(struct seq_file *f,
+                  struct file *filp, struct files_struct *files)
+{
+        struct inode *inode = file_inode(filp);
+        struct file_lock_context *ctx;
+        int id = 0;
+
+        ctx = inode->i_flctx;
+        if (!ctx)
+                return;
+
+        spin_lock(&ctx->flc_lock);
+        __show_fd_locks(f, &ctx->flc_flock, &id, filp, files);
+        __show_fd_locks(f, &ctx->flc_posix, &id, filp, files);
+        __show_fd_locks(f, &ctx->flc_lease, &id, filp, files);
+        spin_unlock(&ctx->flc_lock);
+}
+
 static void *locks_start(struct seq_file *f, loff_t *pos)
         __acquires(&blocked_lock_lock)
 {
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index 8e5ad83b629a..af84ad04df77 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -8,6 +8,7 @@
 #include <linux/security.h>
 #include <linux/file.h>
 #include <linux/seq_file.h>
+#include <linux/fs.h>
 
 #include <linux/proc_fs.h>
 
@@ -48,17 +49,23 @@ static int seq_show(struct seq_file *m, void *v)
                 put_files_struct(files);
         }
 
-        if (!ret) {
-                seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\n",
-                           (long long)file->f_pos, f_flags,
-                           real_mount(file->f_path.mnt)->mnt_id);
-                if (file->f_op->show_fdinfo)
-                        file->f_op->show_fdinfo(m, file);
-                ret = seq_has_overflowed(m);
-                fput(file);
-        }
+        if (ret)
+                return ret;
 
-        return ret;
+        seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\n",
+                   (long long)file->f_pos, f_flags,
+                   real_mount(file->f_path.mnt)->mnt_id);
+
+        show_fd_locks(m, file, files);
+        if (seq_has_overflowed(m))
+                goto out;
+
+        if (file->f_op->show_fdinfo)
+                file->f_op->show_fdinfo(m, file);
+
+out:
+        fput(file);
+        return 0;
 }
 
 static int seq_fdinfo_open(struct inode *inode, struct file *file)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 6bf7ab7c1573..c4e927358503 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1042,6 +1042,9 @@ extern void lease_get_mtime(struct inode *, struct timespec *time);
 extern int generic_setlease(struct file *, long, struct file_lock **, void **priv);
 extern int vfs_setlease(struct file *, long, struct file_lock **, void **);
 extern int lease_modify(struct file_lock *, int, struct list_head *);
+struct files_struct;
+extern void show_fd_locks(struct seq_file *f,
+                         struct file *filp, struct files_struct *files);
 #else /* !CONFIG_FILE_LOCKING */
 static inline int fcntl_getlk(struct file *file, unsigned int cmd,
                               struct flock __user *user)
@@ -1178,6 +1181,10 @@ static inline int lease_modify(struct file_lock *fl, int arg,
 {
         return -EINVAL;
 }
+
+struct files_struct;
+static inline void show_fd_locks(struct seq_file *f,
+                        struct file *filp, struct files_struct *files) {}
 #endif /* !CONFIG_FILE_LOCKING */