btrfs_ordered_update_i_size can be called by truncate and endio, but only endio
takes ordered_extent which contains the completed IO.
while truncating down a file, if there are some in-flight IOs,
btrfs_ordered_update_i_size in endio will set disk_i_size to @orig_offset that
is zero. If truncating-down fails somehow, we try to recover in memory isize
with this zero'd disk_i_size.
Fix it by only updating disk_i_size with @orig_offset when
btrfs_ordered_update_i_size is not called from endio while truncating down and
waiting for in-flight IOs completing their work before recover in-memory size.
Besides fixing the above issue, add an assertion for last_size to double check
we truncate down to the desired size.
Signed-off-by: Liu Bo <bo.li....@oracle.com>
---
fs/btrfs/inode.c | 14 ++++++++++++++
fs/btrfs/ordered-data.c | 9 +++++++--
2 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 09157dd..ef3594d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4682,6 +4682,13 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle
*trans,
btrfs_free_path(path);
+ if (err == 0) {
+ /* only inline file may have last_size != new_size */
+ if (new_size >= root->sectorsize ||
+ new_size > root->fs_info->max_inline)
+ ASSERT(last_size == new_size);
+ }
+
if (be_nice && bytes_deleted > SZ_32M) {
unsigned long updates = trans->delayed_ref_updates;
if (updates) {
@@ -5064,6 +5071,13 @@ static int btrfs_setsize(struct inode *inode, struct
iattr *attr)
if (ret && inode->i_nlink) {
int err;
+ /* To get a stable disk_i_size */
+ err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
+ if (err) {
+ btrfs_orphan_del(NULL, inode);
+ return err;
+ }
+
/*
* failed to truncate, disk_i_size is only adjusted down
* as we remove extents, so it should represent the true
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index b2d1e95..5eaa25a 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -982,8 +982,13 @@ int btrfs_ordered_update_i_size(struct inode *inode, u64
offset,
}
disk_i_size = BTRFS_I(inode)->disk_i_size;
- /* truncate file */
- if (disk_i_size > i_size) {
+ /*
+ * truncate file.
+ * If ordered is not NULL, then this is called from endio and
+ * disk_i_size will be updated by either truncate itself or any
+ * in-flight IOs which are inside the disk_i_size.
+ */
+ if (!ordered && disk_i_size > i_size) {
BTRFS_I(inode)->disk_i_size = orig_offset;
ret = 0;
goto out;
--
2.5.5
--
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