Fix btrfs_get_extent and get_block corner cases, and disable O_DIRECT reads
The generic O_DIRECT code assumes all the bios have the same bdev,
which isn't true for multi-device btrfs.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e875c7c..abfe86d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -494,6 +494,7 @@
bio->bi_end_io = failed_bio->bi_end_io;
bio->bi_sector = failrec->logical >> 9;
bio->bi_bdev = failed_bio->bi_bdev;
+ bio->bi_size = 0;
bio_add_page(bio, page, failrec->len, start - page_offset(page));
btrfs_submit_bio_hook(inode, READ, bio, failrec->last_mirror);
return 0;
@@ -2187,12 +2188,9 @@
spin_unlock(&em_tree->lock);
if (em) {
- if (em->start > start) {
- printk("get_extent lookup [%Lu %Lu] em [%Lu %Lu]\n",
- start, len, em->start, em->len);
- WARN_ON(1);
- }
- if (em->block_start == EXTENT_MAP_INLINE && page)
+ if (em->start > start || em->start + em->len <= start)
+ free_extent_map(em);
+ else if (em->block_start == EXTENT_MAP_INLINE && page)
free_extent_map(em);
else
goto out;
@@ -2340,7 +2338,6 @@
err = 0;
spin_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
-
/* it is possible that someone inserted the extent into the tree
* while we had the lock dropped. It is also possible that
* an overlapping map exists in the tree
@@ -2348,6 +2345,11 @@
if (ret == -EEXIST) {
struct extent_map *existing;
existing = lookup_extent_mapping(em_tree, start, len);
+ if (existing && (existing->start > start ||
+ existing->start + existing->len <= start)) {
+ free_extent_map(existing);
+ existing = NULL;
+ }
if (!existing) {
existing = lookup_extent_mapping(em_tree, em->start,
em->len);
@@ -2388,6 +2390,7 @@
return em;
}
+#if 0 /* waiting for O_DIRECT reads */
static int btrfs_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
@@ -2405,22 +2408,24 @@
if (!em || IS_ERR(em))
goto out;
- if (em->start > start || em->start + em->len <= start)
+ if (em->start > start || em->start + em->len <= start) {
goto out;
+ }
if (em->block_start == EXTENT_MAP_INLINE) {
ret = -EINVAL;
goto out;
}
- if (em->block_start == EXTENT_MAP_HOLE ||
- em->block_start == EXTENT_MAP_DELALLOC) {
- goto out;
- }
-
len = em->start + em->len - start;
len = min_t(u64, len, INT_LIMIT(typeof(bh_result->b_size)));
+ if (em->block_start == EXTENT_MAP_HOLE ||
+ em->block_start == EXTENT_MAP_DELALLOC) {
+ bh_result->b_size = len;
+ goto out;
+ }
+
logical = start - em->start;
logical = em->block_start + logical;
@@ -2430,6 +2435,7 @@
BUG_ON(ret);
bh_result->b_blocknr = multi->stripes[0].physical >> inode->i_blkbits;
bh_result->b_size = min(map_length, len);
+
bh_result->b_bdev = multi->stripes[0].dev->bdev;
set_buffer_mapped(bh_result);
kfree(multi);
@@ -2437,11 +2443,14 @@
free_extent_map(em);
return ret;
}
+#endif
static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
const struct iovec *iov, loff_t offset,
unsigned long nr_segs)
{
+ return -EINVAL;
+#if 0
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
@@ -2450,6 +2459,7 @@
return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
offset, nr_segs, btrfs_get_block, NULL);
+#endif
}
static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
