diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index e71ef97d0a7cabb236e8cbd073667b2e3d143dca..c843563914cad08e2dd84ef1741e19d933f092ee 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1307,12 +1307,12 @@ void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
*
* @objectid: root id
* @anon_dev: preallocated anonymous block device number for new roots,
- * pass 0 for new allocation.
+ * pass NULL for a new allocation.
* @check_ref: whether to check root item references, If true, return -ENOENT
* for orphan roots
*/
static struct btrfs_root *btrfs_get_root_ref(struct btrfs_fs_info *fs_info,
- u64 objectid, dev_t anon_dev,
+ u64 objectid, dev_t *anon_dev,
bool check_ref)
{
struct btrfs_root *root;
@@ -1342,9 +1342,9 @@ static struct btrfs_root *btrfs_get_root_ref(struct btrfs_fs_info *fs_info,
* that common but still possible. In that case, we just need
* to free the anon_dev.
*/
- if (unlikely(anon_dev)) {
- free_anon_bdev(anon_dev);
- anon_dev = 0;
+ if (unlikely(anon_dev && *anon_dev)) {
+ free_anon_bdev(*anon_dev);
+ *anon_dev = 0;
}
if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
@@ -1366,7 +1366,7 @@ static struct btrfs_root *btrfs_get_root_ref(struct btrfs_fs_info *fs_info,
goto fail;
}
- ret = btrfs_init_fs_root(root, anon_dev);
+ ret = btrfs_init_fs_root(root, anon_dev ? *anon_dev : 0);
if (ret)
goto fail;
@@ -1402,7 +1402,7 @@ static struct btrfs_root *btrfs_get_root_ref(struct btrfs_fs_info *fs_info,
* root's anon_dev to 0 to avoid a double free, once by btrfs_put_root()
* and once again by our caller.
*/
- if (anon_dev)
+ if (anon_dev && *anon_dev)
root->anon_dev = 0;
btrfs_put_root(root);
return ERR_PTR(ret);
@@ -1418,7 +1418,7 @@ static struct btrfs_root *btrfs_get_root_ref(struct btrfs_fs_info *fs_info,
struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
u64 objectid, bool check_ref)
{
- return btrfs_get_root_ref(fs_info, objectid, 0, check_ref);
+ return btrfs_get_root_ref(fs_info, objectid, NULL, check_ref);
}
/*
@@ -1426,11 +1426,11 @@ struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
* the anonymous block device id
*
* @objectid: tree objectid
- * @anon_dev: if zero, allocate a new anonymous block device or use the
- * parameter value
+ * @anon_dev: if NULL, allocate a new anonymous block device or use the
+ * parameter value if not NULL
*/
struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
- u64 objectid, dev_t anon_dev)
+ u64 objectid, dev_t *anon_dev)
{
return btrfs_get_root_ref(fs_info, objectid, anon_dev, true);
}
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 9413726b329bb123202a66cf341320ca2d99e410..eb3473d1c1ac1b239092a594cf0f788f961b4943 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -61,7 +61,7 @@ void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
u64 objectid, bool check_ref);
struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
- u64 objectid, dev_t anon_dev);
+ u64 objectid, dev_t *anon_dev);
struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
struct btrfs_path *path,
u64 objectid);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 3e19a2475ab3731c6d7c44c20dfdbf13b4200462..8b4bef05e22217cfe43af497060889e0e5b02d0a 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2480,6 +2480,7 @@ static int emit_fiemap_extent(struct fiemap_extent_info *fieinfo,
struct fiemap_cache *cache,
u64 offset, u64 phys, u64 len, u32 flags)
{
+ u64 cache_end;
int ret = 0;
/* Set at the end of extent_fiemap(). */
@@ -2489,15 +2490,102 @@ static int emit_fiemap_extent(struct fiemap_extent_info *fieinfo,
goto assign;
/*
- * Sanity check, extent_fiemap() should have ensured that new
- * fiemap extent won't overlap with cached one.
- * Not recoverable.
+ * When iterating the extents of the inode, at extent_fiemap(), we may
+ * find an extent that starts at an offset behind the end offset of the
+ * previous extent we processed. This happens if fiemap is called
+ * without FIEMAP_FLAG_SYNC and there are ordered extents completing
+ * while we call btrfs_next_leaf() (through fiemap_next_leaf_item()).
*
- * NOTE: Physical address can overlap, due to compression
+ * For example we are in leaf X processing its last item, which is the
+ * file extent item for file range [512K, 1M[, and after
+ * btrfs_next_leaf() releases the path, there's an ordered extent that
+ * completes for the file range [768K, 2M[, and that results in trimming
+ * the file extent item so that it now corresponds to the file range
+ * [512K, 768K[ and a new file extent item is inserted for the file
+ * range [768K, 2M[, which may end up as the last item of leaf X or as
+ * the first item of the next leaf - in either case btrfs_next_leaf()
+ * will leave us with a path pointing to the new extent item, for the
+ * file range [768K, 2M[, since that's the first key that follows the
+ * last one we processed. So in order not to report overlapping extents
+ * to user space, we trim the length of the previously cached extent and
+ * emit it.
+ *
+ * Upon calling btrfs_next_leaf() we may also find an extent with an
+ * offset smaller than or equals to cache->offset, and this happens
+ * when we had a hole or prealloc extent with several delalloc ranges in
+ * it, but after btrfs_next_leaf() released the path, delalloc was
+ * flushed and the resulting ordered extents were completed, so we can
+ * now have found a file extent item for an offset that is smaller than
+ * or equals to what we have in cache->offset. We deal with this as
+ * described below.
*/
- if (cache->offset + cache->len > offset) {
- WARN_ON(1);
- return -EINVAL;
+ cache_end = cache->offset + cache->len;
+ if (cache_end > offset) {
+ if (offset == cache->offset) {
+ /*
+ * We cached a dealloc range (found in the io tree) for
+ * a hole or prealloc extent and we have now found a
+ * file extent item for the same offset. What we have
+ * now is more recent and up to date, so discard what
+ * we had in the cache and use what we have just found.
+ */
+ goto assign;
+ } else if (offset > cache->offset) {
+ /*
+ * The extent range we previously found ends after the
+ * offset of the file extent item we found and that
+ * offset falls somewhere in the middle of that previous
+ * extent range. So adjust the range we previously found
+ * to end at the offset of the file extent item we have
+ * just found, since this extent is more up to date.
+ * Emit that adjusted range and cache the file extent
+ * item we have just found. This corresponds to the case
+ * where a previously found file extent item was split
+ * due to an ordered extent completing.
+ */
+ cache->len = offset - cache->offset;
+ goto emit;
+ } else {
+ const u64 range_end = offset + len;
+
+ /*
+ * The offset of the file extent item we have just found
+ * is behind the cached offset. This means we were
+ * processing a hole or prealloc extent for which we
+ * have found delalloc ranges (in the io tree), so what
+ * we have in the cache is the last delalloc range we
+ * found while the file extent item we found can be
+ * either for a whole delalloc range we previously
+ * emmitted or only a part of that range.
+ *
+ * We have two cases here:
+ *
+ * 1) The file extent item's range ends at or behind the
+ * cached extent's end. In this case just ignore the
+ * current file extent item because we don't want to
+ * overlap with previous ranges that may have been
+ * emmitted already;
+ *
+ * 2) The file extent item starts behind the currently
+ * cached extent but its end offset goes beyond the
+ * end offset of the cached extent. We don't want to
+ * overlap with a previous range that may have been
+ * emmitted already, so we emit the currently cached
+ * extent and then partially store the current file
+ * extent item's range in the cache, for the subrange
+ * going the cached extent's end to the end of the
+ * file extent item.
+ */
+ if (range_end <= cache_end)
+ return 0;
+
+ if (!(flags & (FIEMAP_EXTENT_ENCODED | FIEMAP_EXTENT_DELALLOC)))
+ phys += cache_end - offset;
+
+ offset = cache_end;
+ len = range_end - cache_end;
+ goto emit;
+ }
}
/*
@@ -2517,6 +2605,7 @@ static int emit_fiemap_extent(struct fiemap_extent_info *fieinfo,
return 0;
}
+emit:
/* Not mergeable, need to submit cached one */
ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
cache->len, cache->flags);
@@ -2907,17 +2996,15 @@ int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
range_end = round_up(start + len, sectorsize);
prev_extent_end = range_start;
- btrfs_inode_lock(inode, BTRFS_ILOCK_SHARED);
-
ret = fiemap_find_last_extent_offset(inode, path, &last_extent_end);
if (ret < 0)
- goto out_unlock;
+ goto out;
btrfs_release_path(path);
path->reada = READA_FORWARD;
ret = fiemap_search_slot(inode, path, range_start);
if (ret < 0) {
- goto out_unlock;
+ goto out;
} else if (ret > 0) {
/*
* No file extent item found, but we may have delalloc between
@@ -2964,7 +3051,7 @@ int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
backref_ctx, 0, 0, 0,
prev_extent_end, hole_end);
if (ret < 0) {
- goto out_unlock;
+ goto out;
} else if (ret > 0) {
/* fiemap_fill_next_extent() told us to stop. */
stopped = true;
@@ -3020,7 +3107,7 @@ int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
extent_gen,
backref_ctx);
if (ret < 0)
- goto out_unlock;
+ goto out;
else if (ret > 0)
flags |= FIEMAP_EXTENT_SHARED;
}
@@ -3031,7 +3118,7 @@ int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
}
if (ret < 0) {
- goto out_unlock;
+ goto out;
} else if (ret > 0) {
/* fiemap_fill_next_extent() told us to stop. */
stopped = true;
@@ -3042,12 +3129,12 @@ int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
next_item:
if (fatal_signal_pending(current)) {
ret = -EINTR;
- goto out_unlock;
+ goto out;
}
ret = fiemap_next_leaf_item(inode, path);
if (ret < 0) {
- goto out_unlock;
+ goto out;
} else if (ret > 0) {
/* No more file extent items for this inode. */
break;
@@ -3071,7 +3158,7 @@ int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
&delalloc_cached_state, backref_ctx,
0, 0, 0, prev_extent_end, range_end - 1);
if (ret < 0)
- goto out_unlock;
+ goto out;
prev_extent_end = range_end;
}
@@ -3109,9 +3196,6 @@ int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
}
ret = emit_last_fiemap_cache(fieinfo, &cache);
-
-out_unlock:
- btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
out:
free_extent_state(delalloc_cached_state);
btrfs_free_backref_share_ctx(backref_ctx);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f88e0ca8331d9b5448e8e07c89e5e66395c782b3..4795738d5785bce730fad21b68a00ff729b97915 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7835,6 +7835,7 @@ struct iomap_dio *btrfs_dio_write(struct kiocb *iocb, struct iov_iter *iter,
static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
u64 start, u64 len)
{
+ struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
int ret;
ret = fiemap_prep(inode, fieinfo, start, &len, 0);
@@ -7860,7 +7861,26 @@ static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
return ret;
}
- return extent_fiemap(BTRFS_I(inode), fieinfo, start, len);
+ btrfs_inode_lock(btrfs_inode, BTRFS_ILOCK_SHARED);
+
+ /*
+ * We did an initial flush to avoid holding the inode's lock while
+ * triggering writeback and waiting for the completion of IO and ordered
+ * extents. Now after we locked the inode we do it again, because it's
+ * possible a new write may have happened in between those two steps.
+ */
+ if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC) {
+ ret = btrfs_wait_ordered_range(inode, 0, LLONG_MAX);
+ if (ret) {
+ btrfs_inode_unlock(btrfs_inode, BTRFS_ILOCK_SHARED);
+ return ret;
+ }
+ }
+
+ ret = extent_fiemap(btrfs_inode, fieinfo, start, len);
+ btrfs_inode_unlock(btrfs_inode, BTRFS_ILOCK_SHARED);
+
+ return ret;
}
static int btrfs_writepages(struct address_space *mapping,
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ac3316e0d11c3a42835dc8a2094b00a16019bd64..9d1eac15e09e141212cf0edadffcca873cba58f1 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -721,7 +721,7 @@ static noinline int create_subvol(struct mnt_idmap *idmap,
free_extent_buffer(leaf);
leaf = NULL;
- new_root = btrfs_get_new_fs_root(fs_info, objectid, anon_dev);
+ new_root = btrfs_get_new_fs_root(fs_info, objectid, &anon_dev);
if (IS_ERR(new_root)) {
ret = PTR_ERR(new_root);
btrfs_abort_transaction(trans, ret);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index c52807d97efa553b0b5e4765e11606a8ce644161..bf8e64c766b63b4c8b424f4437791eaea12f24a2 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1834,7 +1834,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
}
key.offset = (u64)-1;
- pending->snap = btrfs_get_new_fs_root(fs_info, objectid, pending->anon_dev);
+ pending->snap = btrfs_get_new_fs_root(fs_info, objectid, &pending->anon_dev);
if (IS_ERR(pending->snap)) {
ret = PTR_ERR(pending->snap);
pending->snap = NULL;