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authorJosef Bacik <jbacik@fusionio.com>2013-08-29 13:57:21 -0400
committerChris Mason <chris.mason@fusionio.com>2013-09-01 08:16:34 -0400
commit77cef2ec5484564eca6bd12a2b4a1e88fd766fbc (patch)
treeedc2b57493ccebe4dc4ad48daf03a2ac25f24a10 /fs/btrfs/ordered-data.c
parentb12d6869f67a95692017d26313ea5736d4043d0f (diff)
downloadop-kernel-dev-77cef2ec5484564eca6bd12a2b4a1e88fd766fbc.zip
op-kernel-dev-77cef2ec5484564eca6bd12a2b4a1e88fd766fbc.tar.gz
Btrfs: allow partial ordered extent completion
We currently have this problem where you can truncate pages that have not yet been written for an ordered extent. We do this because the truncate will be coming behind to clean us up anyway so what's the harm right? Well if truncate fails for whatever reason we leave an orphan item around for the file to be cleaned up later. But if the user goes and truncates up the file and tries to read from the area that had been discarded previously they will get a csum error because we never actually wrote that data out. This patch fixes this by allowing us to either discard the ordered extent completely, by which I mean we just free up the space we had allocated and not add the file extent, or adjust the length of the file extent we write. We do this by setting the length we truncated down to in the ordered extent, and then we set the file extent length and ram bytes to this length. The total disk space stays unchanged since we may be compressed and we can't just chop off the disk space, but at least this way the file extent only points to the valid data. Then when the file extent is free'd the extent and csums will be freed normally. This patch is needed for the next series which will give us more graceful recovery of failed truncates. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Diffstat (limited to 'fs/btrfs/ordered-data.c')
-rw-r--r--fs/btrfs/ordered-data.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index f2023cc..966b413 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -205,6 +205,7 @@ static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
entry->bytes_left = len;
entry->inode = igrab(inode);
entry->compress_type = compress_type;
+ entry->truncated_len = (u64)-1;
if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
set_bit(type, &entry->flags);
@@ -920,12 +921,16 @@ int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
struct btrfs_ordered_extent *test;
int ret = 1;
- if (ordered)
+ spin_lock_irq(&tree->lock);
+ if (ordered) {
offset = entry_end(ordered);
- else
+ if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
+ offset = min(offset,
+ ordered->file_offset +
+ ordered->truncated_len);
+ } else {
offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
-
- spin_lock_irq(&tree->lock);
+ }
disk_i_size = BTRFS_I(inode)->disk_i_size;
/* truncate file */
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