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/extent_io.c b/fs/btrfs/extent_io.c
index 81f8b4f..6e4bf02 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1694,6 +1694,7 @@ extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
        }
 
        if (bio) {
+               bio->bi_size = 0;
                bio->bi_bdev = bdev;
                bio->bi_sector = first_sector;
        }

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e875c7c..abfe86d 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -494,6 +494,7 @@ int btrfs_readpage_io_failed_hook(struct bio *failed_bio,
        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 @@ again:
        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 @@ insert:
        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 @@ insert:
        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 @@ out:
        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 @@ static int btrfs_get_block(struct inode *inode, sector_t iblock,
        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;
        }
 
+       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;
        }
 
-       len = em->start + em->len - start;
-       len = min_t(u64, len, INT_LIMIT(typeof(bh_result->b_size)));
-
        logical = start - em->start;
        logical = em->block_start + logical;
 
@@ -2430,6 +2435,7 @@ static int btrfs_get_block(struct inode *inode, sector_t iblock,
        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 @@ out:
        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 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
 
        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)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5619e50..bccb556 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1161,7 +1161,6 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
        int total_devs = 1;
 
        length = bio->bi_size;
-
        map_tree = &root->fs_info->mapping_tree;
        map_length = length;
 
@@ -1192,6 +1191,7 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
                }
                bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
                dev = multi->stripes[dev_nr].dev;
+
                bio->bi_bdev = dev->bdev;
                spin_lock(&dev->io_lock);
                dev->total_ios++;