Patchwork [3/3,v3] Ext4: handle SEEK_HOLE/SEEK_DATA generically

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Submitter Josef Bacik
Date May 5, 2011, 8:16 p.m.
Message ID <1304626619-1588-3-git-send-email-josef@redhat.com>
Download mbox | patch
Permalink /patch/94314/
State Not Applicable
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Comments

Josef Bacik - May 5, 2011, 8:16 p.m.
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@redhat.com>
---
v2->v3: Nothing since this is the first time posting this :)
 fs/ext4/file.c |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)

Patch

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 7b80d54..7ec6e2d 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:
+		/*
+		 * For now the entire file is considered data, so the only valid
+		 * next data section is position 0.
+		 */
+		if (offset != 0 || inode->i_size == 0) {
+			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) {