return ret;
}
+static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
+ struct extent_state **cached_state, int writing)
+{
+ struct btrfs_ordered_extent *ordered;
+ int ret = 0;
+
+ while (1) {
+ lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+ 0, cached_state);
+ /*
+ * We're concerned with the entire range that we're going to be
+ * doing DIO to, so we need to make sure theres no ordered
+ * extents in this range.
+ */
+ ordered = btrfs_lookup_ordered_range(inode, lockstart,
+ lockend - lockstart + 1);
+
+ /*
+ * We need to make sure there are no buffered pages in this
+ * range either, we could have raced between the invalidate in
+ * generic_file_direct_write and locking the extent. The
+ * invalidate needs to happen so that reads after a write do not
+ * get stale data.
+ */
+ if (!ordered && (!writing ||
+ !test_range_bit(&BTRFS_I(inode)->io_tree,
+ lockstart, lockend, EXTENT_UPTODATE, 0,
+ *cached_state)))
+ break;
+
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+ cached_state, GFP_NOFS);
+
+ if (ordered) {
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ } else {
+ /* Screw you mmap */
+ ret = filemap_write_and_wait_range(inode->i_mapping,
+ lockstart,
+ lockend);
+ if (ret)
+ break;
+
+ /*
+ * If we found a page that couldn't be invalidated just
+ * fall back to buffered.
+ */
+ ret = invalidate_inode_pages2_range(inode->i_mapping,
+ lockstart >> PAGE_CACHE_SHIFT,
+ lockend >> PAGE_CACHE_SHIFT);
+ if (ret)
+ break;
+ }
+
+ cond_resched();
+ }
+
+ return ret;
+}
+
static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_state *cached_state = NULL;
u64 start = iblock << inode->i_blkbits;
+ u64 lockstart, lockend;
u64 len = bh_result->b_size;
struct btrfs_trans_handle *trans;
+ int unlock_bits = EXTENT_LOCKED;
+ int ret;
+
+ lockstart = start;
+ lockend = start + len - 1;
+ if (create) {
+ ret = btrfs_delalloc_reserve_space(inode, len);
+ if (ret)
+ return ret;
+ unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
+ }
+
+ /*
+ * If this errors out it's because we couldn't invalidate pagecache for
+ * this range and we need to fallback to buffered.
+ */
+ if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
+ return -ENOTBLK;
+
+ if (create) {
+ ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
+ lockend, EXTENT_DELALLOC, NULL,
+ &cached_state, GFP_NOFS);
+ if (ret)
+ goto unlock_err;
+ }
em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
- if (IS_ERR(em))
- return PTR_ERR(em);
+ if (IS_ERR(em)) {
+ ret = PTR_ERR(em);
+ goto unlock_err;
+ }
/*
* Ok for INLINE and COMPRESSED extents we need to fallback on buffered
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
em->block_start == EXTENT_MAP_INLINE) {
free_extent_map(em);
- return -ENOTBLK;
+ ret = -ENOTBLK;
+ goto unlock_err;
}
/* Just a good old fashioned hole, return */
if (!create && (em->block_start == EXTENT_MAP_HOLE ||
test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
free_extent_map(em);
- /* DIO will do one hole at a time, so just unlock a sector */
- unlock_extent(&BTRFS_I(inode)->io_tree, start,
- start + root->sectorsize - 1);
- return 0;
+ ret = 0;
+ goto unlock_err;
}
/*
*
*/
if (!create) {
- len = em->len - (start - em->start);
- goto map;
+ len = min(len, em->len - (start - em->start));
+ lockstart = start + len;
+ goto unlock;
}
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
btrfs_end_transaction(trans, root);
if (ret) {
free_extent_map(em);
- return ret;
+ goto unlock_err;
}
goto unlock;
}
*/
len = bh_result->b_size;
em = btrfs_new_extent_direct(inode, em, start, len);
- if (IS_ERR(em))
- return PTR_ERR(em);
+ if (IS_ERR(em)) {
+ ret = PTR_ERR(em);
+ goto unlock_err;
+ }
len = min(len, em->len - (start - em->start));
unlock:
- clear_extent_bit(&BTRFS_I(inode)->io_tree, start, start + len - 1,
- EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DIRTY, 1,
- 0, NULL, GFP_NOFS);
-map:
bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
inode->i_blkbits;
bh_result->b_size = len;
i_size_write(inode, start + len);
}
+ /*
+ * In the case of write we need to clear and unlock the entire range,
+ * in the case of read we need to unlock only the end area that we
+ * aren't using if there is any left over space.
+ */
+ if (lockstart < lockend)
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+ unlock_bits, 1, 0, &cached_state, GFP_NOFS);
+ else
+ free_extent_state(cached_state);
+
free_extent_map(em);
return 0;
+
+unlock_err:
+ if (create)
+ unlock_bits |= EXTENT_DO_ACCOUNTING;
+
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+ unlock_bits, 1, 0, &cached_state, GFP_NOFS);
+ return ret;
}
struct btrfs_dio_private {
out:
return retval;
}
+
static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
const struct iovec *iov, loff_t offset,
unsigned long nr_segs)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
- struct btrfs_ordered_extent *ordered;
- struct extent_state *cached_state = NULL;
- u64 lockstart, lockend;
- ssize_t ret;
- int writing = rw & WRITE;
- int write_bits = 0;
- size_t count = iov_length(iov, nr_segs);
if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
- offset, nr_segs)) {
+ offset, nr_segs))
return 0;
- }
-
- lockstart = offset;
- lockend = offset + count - 1;
-
- if (writing) {
- ret = btrfs_delalloc_reserve_space(inode, count);
- if (ret)
- goto out;
- }
- while (1) {
- lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
- 0, &cached_state);
- /*
- * We're concerned with the entire range that we're going to be
- * doing DIO to, so we need to make sure theres no ordered
- * extents in this range.
- */
- ordered = btrfs_lookup_ordered_range(inode, lockstart,
- lockend - lockstart + 1);
-
- /*
- * We need to make sure there are no buffered pages in this
- * range either, we could have raced between the invalidate in
- * generic_file_direct_write and locking the extent. The
- * invalidate needs to happen so that reads after a write do not
- * get stale data.
- */
- if (!ordered && (!writing ||
- !test_range_bit(&BTRFS_I(inode)->io_tree,
- lockstart, lockend, EXTENT_UPTODATE, 0,
- cached_state)))
- break;
-
- unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
- &cached_state, GFP_NOFS);
-
- if (ordered) {
- btrfs_start_ordered_extent(inode, ordered, 1);
- btrfs_put_ordered_extent(ordered);
- } else {
- /* Screw you mmap */
- ret = filemap_write_and_wait_range(file->f_mapping,
- lockstart,
- lockend);
- if (ret)
- goto out;
-
- /*
- * If we found a page that couldn't be invalidated just
- * fall back to buffered.
- */
- ret = invalidate_inode_pages2_range(file->f_mapping,
- lockstart >> PAGE_CACHE_SHIFT,
- lockend >> PAGE_CACHE_SHIFT);
- if (ret) {
- if (ret == -EBUSY)
- ret = 0;
- goto out;
- }
- }
-
- cond_resched();
- }
-
- /*
- * we don't use btrfs_set_extent_delalloc because we don't want
- * the dirty or uptodate bits
- */
- if (writing) {
- write_bits = EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING;
- ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
- EXTENT_DELALLOC, NULL, &cached_state,
- GFP_NOFS);
- if (ret) {
- clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
- lockend, EXTENT_LOCKED | write_bits,
- 1, 0, &cached_state, GFP_NOFS);
- goto out;
- }
- }
-
- free_extent_state(cached_state);
- cached_state = NULL;
-
- ret = __blockdev_direct_IO(rw, iocb, inode,
+ return __blockdev_direct_IO(rw, iocb, inode,
BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
btrfs_submit_direct, 0);
-
- if (ret < 0 && ret != -EIOCBQUEUED) {
- clear_extent_bit(&BTRFS_I(inode)->io_tree, offset,
- offset + iov_length(iov, nr_segs) - 1,
- EXTENT_LOCKED | write_bits, 1, 0,
- &cached_state, GFP_NOFS);
- } else if (ret >= 0 && ret < iov_length(iov, nr_segs)) {
- /*
- * We're falling back to buffered, unlock the section we didn't
- * do IO on.
- */
- clear_extent_bit(&BTRFS_I(inode)->io_tree, offset + ret,
- offset + iov_length(iov, nr_segs) - 1,
- EXTENT_LOCKED | write_bits, 1, 0,
- &cached_state, GFP_NOFS);
- }
-out:
- free_extent_state(cached_state);
- return ret;
}
static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
projects / users / hch / configfs.git / commitdiff