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-rw-r--r--fs/btrfs/btrfs_inode.h10
-rw-r--r--fs/btrfs/disk-io.c10
-rw-r--r--fs/btrfs/extent_io.c60
-rw-r--r--fs/btrfs/file.c16
-rw-r--r--fs/btrfs/ordered-data.c31
-rw-r--r--fs/btrfs/tree-log.c17
6 files changed, 100 insertions, 44 deletions
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 91c994b569f3..6ed495ca7a31 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -89,6 +89,16 @@ enum {
BTRFS_INODE_FREE_SPACE_INODE,
/* Set when there are no capabilities in XATTs for the inode. */
BTRFS_INODE_NO_CAP_XATTR,
+ /*
+ * Set if an error happened when doing a COW write before submitting a
+ * bio or during writeback. Used for both buffered writes and direct IO
+ * writes. This is to signal a fast fsync that it has to wait for
+ * ordered extents to complete and therefore not log extent maps that
+ * point to unwritten extents (when an ordered extent completes and it
+ * has the BTRFS_ORDERED_IOERR flag set, it drops extent maps in its
+ * range).
+ */
+ BTRFS_INODE_COW_WRITE_ERROR,
};
/* in memory btrfs inode */
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 1b20b3e390df..38cdb8875e8e 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -4538,18 +4538,10 @@ static void btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
struct btrfs_fs_info *fs_info)
{
struct rb_node *node;
- struct btrfs_delayed_ref_root *delayed_refs;
+ struct btrfs_delayed_ref_root *delayed_refs = &trans->delayed_refs;
struct btrfs_delayed_ref_node *ref;
- delayed_refs = &trans->delayed_refs;
-
spin_lock(&delayed_refs->lock);
- if (atomic_read(&delayed_refs->num_entries) == 0) {
- spin_unlock(&delayed_refs->lock);
- btrfs_debug(fs_info, "delayed_refs has NO entry");
- return;
- }
-
while ((node = rb_first_cached(&delayed_refs->href_root)) != NULL) {
struct btrfs_delayed_ref_head *head;
struct rb_node *n;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 597387e9f040..f688fab55251 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3689,6 +3689,8 @@ static struct extent_buffer *grab_extent_buffer(
struct folio *folio = page_folio(page);
struct extent_buffer *exists;
+ lockdep_assert_held(&page->mapping->i_private_lock);
+
/*
* For subpage case, we completely rely on radix tree to ensure we
* don't try to insert two ebs for the same bytenr. So here we always
@@ -3756,13 +3758,14 @@ static int check_eb_alignment(struct btrfs_fs_info *fs_info, u64 start)
* The caller needs to free the existing folios and retry using the same order.
*/
static int attach_eb_folio_to_filemap(struct extent_buffer *eb, int i,
+ struct btrfs_subpage *prealloc,
struct extent_buffer **found_eb_ret)
{
struct btrfs_fs_info *fs_info = eb->fs_info;
struct address_space *mapping = fs_info->btree_inode->i_mapping;
const unsigned long index = eb->start >> PAGE_SHIFT;
- struct folio *existing_folio;
+ struct folio *existing_folio = NULL;
int ret;
ASSERT(found_eb_ret);
@@ -3774,12 +3777,14 @@ retry:
ret = filemap_add_folio(mapping, eb->folios[i], index + i,
GFP_NOFS | __GFP_NOFAIL);
if (!ret)
- return 0;
+ goto finish;
existing_folio = filemap_lock_folio(mapping, index + i);
/* The page cache only exists for a very short time, just retry. */
- if (IS_ERR(existing_folio))
+ if (IS_ERR(existing_folio)) {
+ existing_folio = NULL;
goto retry;
+ }
/* For now, we should only have single-page folios for btree inode. */
ASSERT(folio_nr_pages(existing_folio) == 1);
@@ -3790,14 +3795,13 @@ retry:
return -EAGAIN;
}
- if (fs_info->nodesize < PAGE_SIZE) {
- /*
- * We're going to reuse the existing page, can drop our page
- * and subpage structure now.
- */
+finish:
+ spin_lock(&mapping->i_private_lock);
+ if (existing_folio && fs_info->nodesize < PAGE_SIZE) {
+ /* We're going to reuse the existing page, can drop our folio now. */
__free_page(folio_page(eb->folios[i], 0));
eb->folios[i] = existing_folio;
- } else {
+ } else if (existing_folio) {
struct extent_buffer *existing_eb;
existing_eb = grab_extent_buffer(fs_info,
@@ -3805,6 +3809,7 @@ retry:
if (existing_eb) {
/* The extent buffer still exists, we can use it directly. */
*found_eb_ret = existing_eb;
+ spin_unlock(&mapping->i_private_lock);
folio_unlock(existing_folio);
folio_put(existing_folio);
return 1;
@@ -3813,6 +3818,22 @@ retry:
__free_page(folio_page(eb->folios[i], 0));
eb->folios[i] = existing_folio;
}
+ eb->folio_size = folio_size(eb->folios[i]);
+ eb->folio_shift = folio_shift(eb->folios[i]);
+ /* Should not fail, as we have preallocated the memory. */
+ ret = attach_extent_buffer_folio(eb, eb->folios[i], prealloc);
+ ASSERT(!ret);
+ /*
+ * To inform we have an extra eb under allocation, so that
+ * detach_extent_buffer_page() won't release the folio private when the
+ * eb hasn't been inserted into radix tree yet.
+ *
+ * The ref will be decreased when the eb releases the page, in
+ * detach_extent_buffer_page(). Thus needs no special handling in the
+ * error path.
+ */
+ btrfs_folio_inc_eb_refs(fs_info, eb->folios[i]);
+ spin_unlock(&mapping->i_private_lock);
return 0;
}
@@ -3824,7 +3845,6 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
int attached = 0;
struct extent_buffer *eb;
struct extent_buffer *existing_eb = NULL;
- struct address_space *mapping = fs_info->btree_inode->i_mapping;
struct btrfs_subpage *prealloc = NULL;
u64 lockdep_owner = owner_root;
bool page_contig = true;
@@ -3890,7 +3910,7 @@ reallocate:
for (int i = 0; i < num_folios; i++) {
struct folio *folio;
- ret = attach_eb_folio_to_filemap(eb, i, &existing_eb);
+ ret = attach_eb_folio_to_filemap(eb, i, prealloc, &existing_eb);
if (ret > 0) {
ASSERT(existing_eb);
goto out;
@@ -3927,24 +3947,6 @@ reallocate:
* and free the allocated page.
*/
folio = eb->folios[i];
- eb->folio_size = folio_size(folio);
- eb->folio_shift = folio_shift(folio);
- spin_lock(&mapping->i_private_lock);
- /* Should not fail, as we have preallocated the memory */
- ret = attach_extent_buffer_folio(eb, folio, prealloc);
- ASSERT(!ret);
- /*
- * To inform we have extra eb under allocation, so that
- * detach_extent_buffer_page() won't release the folio private
- * when the eb hasn't yet been inserted into radix tree.
- *
- * The ref will be decreased when the eb released the page, in
- * detach_extent_buffer_page().
- * Thus needs no special handling in error path.
- */
- btrfs_folio_inc_eb_refs(fs_info, folio);
- spin_unlock(&mapping->i_private_lock);
-
WARN_ON(btrfs_folio_test_dirty(fs_info, folio, eb->start, eb->len));
/*
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index e764ac3f22e2..d90138683a0a 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1885,6 +1885,7 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
*/
if (full_sync || btrfs_is_zoned(fs_info)) {
ret = btrfs_wait_ordered_range(inode, start, len);
+ clear_bit(BTRFS_INODE_COW_WRITE_ERROR, &BTRFS_I(inode)->runtime_flags);
} else {
/*
* Get our ordered extents as soon as possible to avoid doing
@@ -1894,6 +1895,21 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
btrfs_get_ordered_extents_for_logging(BTRFS_I(inode),
&ctx.ordered_extents);
ret = filemap_fdatawait_range(inode->i_mapping, start, end);
+ if (ret)
+ goto out_release_extents;
+
+ /*
+ * Check and clear the BTRFS_INODE_COW_WRITE_ERROR now after
+ * starting and waiting for writeback, because for buffered IO
+ * it may have been set during the end IO callback
+ * (end_bbio_data_write() -> btrfs_finish_ordered_extent()) in
+ * case an error happened and we need to wait for ordered
+ * extents to complete so that any extent maps that point to
+ * unwritten locations are dropped and we don't log them.
+ */
+ if (test_and_clear_bit(BTRFS_INODE_COW_WRITE_ERROR,
+ &BTRFS_I(inode)->runtime_flags))
+ ret = btrfs_wait_ordered_range(inode, start, len);
}
if (ret)
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index c5bdd674f55c..35a413ce935d 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -388,6 +388,37 @@ bool btrfs_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
ret = can_finish_ordered_extent(ordered, page, file_offset, len, uptodate);
spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
+ /*
+ * If this is a COW write it means we created new extent maps for the
+ * range and they point to unwritten locations if we got an error either
+ * before submitting a bio or during IO.
+ *
+ * We have marked the ordered extent with BTRFS_ORDERED_IOERR, and we
+ * are queuing its completion below. During completion, at
+ * btrfs_finish_one_ordered(), we will drop the extent maps for the
+ * unwritten extents.
+ *
+ * However because completion runs in a work queue we can end up having
+ * a fast fsync running before that. In the case of direct IO, once we
+ * unlock the inode the fsync might start, and we queue the completion
+ * before unlocking the inode. In the case of buffered IO when writeback
+ * finishes (end_bbio_data_write()) we queue the completion, so if the
+ * writeback was triggered by a fast fsync, the fsync might start
+ * logging before ordered extent completion runs in the work queue.
+ *
+ * The fast fsync will log file extent items based on the extent maps it
+ * finds, so if by the time it collects extent maps the ordered extent
+ * completion didn't happen yet, it will log file extent items that
+ * point to unwritten extents, resulting in a corruption if a crash
+ * happens and the log tree is replayed. Note that a fast fsync does not
+ * wait for completion of ordered extents in order to reduce latency.
+ *
+ * Set a flag in the inode so that the next fast fsync will wait for
+ * ordered extents to complete before starting to log.
+ */
+ if (!uptodate && !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
+ set_bit(BTRFS_INODE_COW_WRITE_ERROR, &inode->runtime_flags);
+
if (ret)
btrfs_queue_ordered_fn(ordered);
return ret;
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 5146387b416b..26a2e5aa08e9 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -4860,18 +4860,23 @@ static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans,
path->slots[0]++;
continue;
}
- if (!dropped_extents) {
- /*
- * Avoid logging extent items logged in past fsync calls
- * and leading to duplicate keys in the log tree.
- */
+ /*
+ * Avoid overlapping items in the log tree. The first time we
+ * get here, get rid of everything from a past fsync. After
+ * that, if the current extent starts before the end of the last
+ * extent we copied, truncate the last one. This can happen if
+ * an ordered extent completion modifies the subvolume tree
+ * while btrfs_next_leaf() has the tree unlocked.
+ */
+ if (!dropped_extents || key.offset < truncate_offset) {
ret = truncate_inode_items(trans, root->log_root, inode,
- truncate_offset,
+ min(key.offset, truncate_offset),
BTRFS_EXTENT_DATA_KEY);
if (ret)
goto out;
dropped_extents = true;
}
+ truncate_offset = btrfs_file_extent_end(path);
if (ins_nr == 0)
start_slot = slot;
ins_nr++;
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-29 23:01:28 +0000