Fix btrfs_file_llseek() to return -EINVAL directly

Hello,

In btrfs_file_llseek(), if the offset < 0 or offset > inode->i_sb->s_maxbytes, we should return -EINVAL rather than offset. Also, if the offset >= inode->i_size for SEEK_DATA or SEEK_HOLE, return -ENXIO is ok IMHO.

index e7872e4..2c126d0 100644
@@ -1813,6 +1813,11 @@ static loff_t btrfs_file_llseek(struct file 

*file, loff_t offset, int origin)

          goto out;
      case SEEK_DATA:
      case SEEK_HOLE:

+ if (offset >= inode->i_size) {
+ mutex_unlock(&inode->i_mutex);
+ return -ENXIO;
+ }
+

          ret = find_desired_extent(inode, &offset, origin);
          if (ret) {
              mutex_unlock(&inode->i_mutex);
@@ -1820,14 +1825,11 @@ static loff_t btrfs_file_llseek(struct file 
*file, loff_t offset, int origin)
          }
      }

- if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {
- ret = -EINVAL;
- goto out;
- }
- if (offset > inode->i_sb->s_maxbytes) {
- ret = -EINVAL;
- goto out;
- }
+ if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET))
+ return -EINVAL;
+
+ if (offset > inode->i_sb->s_maxbytes)
+ return -EINVAL;

      /* Special lock needed here? */
      if (offset != file->f_pos) {

Sorry, I forgot unlocking inode before returning -EINVAL in the previous patch, thanks Tao pointing this out!

From 1825149c67cbfe7cbafcee4156e1f301dade7b0b Mon Sep 17 00:00:00 2001
From: Jie Liu <[email protected]>
Date: Tue, 30 Aug 2011 11:51:00 +0800
Subject: [PATCH 1/1] Return -EINVAL ranther than offset if offset < 0 or offset >
inode->i_sb->s_maxbytes.

---
 fs/btrfs/file.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

index e7872e4..082ae91 100644
@@ -1813,6 +1813,11 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int origin)
         goto out;
     case SEEK_DATA:
     case SEEK_HOLE:
+        if (offset >= inode->i_size) {
+            mutex_unlock(&inode->i_mutex);
+            return -ENXIO;
+        }
+
         ret = find_desired_extent(inode, &offset, origin);
         if (ret) {
             mutex_unlock(&inode->i_mutex);

@@ -1821,11 +1826,11 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int origin)
     }
 
     if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {
-        ret = -EINVAL;
+        offset = -EINVAL;
         goto out;
     }
     if (offset > inode->i_sb->s_maxbytes) {
-        ret = -EINVAL;
+        offset = -EINVAL;
         goto out;
     }
 

1.7.4.1