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[PATCH 3/4] Ext4: handle SEEK_HOLE/SEEK_DATA generically

To: linux-fsdevel@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, linux-btrfs@xxxxxxxxxxxxxxx, xfs@xxxxxxxxxxx, viro@xxxxxxxxxxxxxxxxxx
Subject: [PATCH 3/4] Ext4: handle SEEK_HOLE/SEEK_DATA generically
From: Josef Bacik <josef@xxxxxxxxxx>
Date: Tue, 28 Jun 2011 11:33:17 -0400
In-reply-to: <1309275199-10801-1-git-send-email-josef@xxxxxxxxxx>
References: <1309275199-10801-1-git-send-email-josef@xxxxxxxxxx>
Since Ext4 has its own lseek we need to make sure it handles
SEEK_HOLE/SEEK_DATA.  For now just do the same thing that is done in the generic
case, somebody else can come along and make it do fancy things later.  Thanks,

Signed-off-by: Josef Bacik <josef@xxxxxxxxxx>
---
 fs/ext4/file.c |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 2c09723..ce766f9 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -236,6 +236,27 @@ loff_t ext4_llseek(struct file *file, loff_t offset, int 
origin)
                }
                offset += file->f_pos;
                break;
+       case SEEK_DATA:
+               /*
+                * In the generic case the entire file is data, so as long as
+                * offset isn't at the end of the file then the offset is data.
+                */
+               if (offset >= inode->i_size) {
+                       mutex_unlock(&inode->i_mutex);
+                       return -ENXIO;
+               }
+               break;
+       case SEEK_HOLE:
+               /*
+                * There is a virtual hole at the end of the file, so as long as
+                * offset isn't i_size or larger, return i_size.
+                */
+               if (offset >= inode->i_size) {
+                       mutex_unlock(&inode->i_mutex);
+                       return -ENXIO;
+               }
+               offset = inode->i_size;
+               break;
        }
 
        if (offset < 0 || offset > maxbytes) {
-- 
1.7.5.2

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