summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--fs/btrfs/extent-io-tree.c52
-rw-r--r--fs/btrfs/extent-io-tree.h3
-rw-r--r--fs/btrfs/extent_io.c3
3 files changed, 43 insertions, 15 deletions
diff --git a/fs/btrfs/extent-io-tree.c b/fs/btrfs/extent-io-tree.c
index 1b0a45b51f4c..a630c771d25c 100644
--- a/fs/btrfs/extent-io-tree.c
+++ b/fs/btrfs/extent-io-tree.c
@@ -714,7 +714,8 @@ static void wait_on_state(struct extent_io_tree *tree,
* The range [start, end] is inclusive.
* The tree lock is taken by this function
*/
-void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, u32 bits)
+void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, u32 bits,
+ struct extent_state **cached_state)
{
struct extent_state *state;
@@ -722,6 +723,16 @@ void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, u32 bits)
spin_lock(&tree->lock);
again:
+ /*
+ * Maintain cached_state, as we may not remove it from the tree if there
+ * are more bits than the bits we're waiting on set on this state.
+ */
+ if (cached_state && *cached_state) {
+ state = *cached_state;
+ if (extent_state_in_tree(state) &&
+ state->start <= start && start < state->end)
+ goto process_node;
+ }
while (1) {
/*
* This search will find all the extents that end after our
@@ -752,6 +763,12 @@ process_node:
}
}
out:
+ /* This state is no longer useful, clear it and free it up. */
+ if (cached_state && *cached_state) {
+ state = *cached_state;
+ *cached_state = NULL;
+ free_extent_state(state);
+ }
spin_unlock(&tree->lock);
}
@@ -939,13 +956,17 @@ out:
* sleeping, so the gfp mask is used to indicate what is allowed.
*
* If any of the exclusive bits are set, this will fail with -EEXIST if some
- * part of the range already has the desired bits set. The start of the
- * existing range is returned in failed_start in this case.
+ * part of the range already has the desired bits set. The extent_state of the
+ * existing range is returned in failed_state in this case, and the start of the
+ * existing range is returned in failed_start. failed_state is used as an
+ * optimization for wait_extent_bit, failed_start must be used as the source of
+ * truth as failed_state may have changed since we returned.
*
* [start, end] is inclusive This takes the tree lock.
*/
static int __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
u32 bits, u64 *failed_start,
+ struct extent_state **failed_state,
struct extent_state **cached_state,
struct extent_changeset *changeset, gfp_t mask)
{
@@ -964,7 +985,7 @@ static int __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
if (exclusive_bits)
ASSERT(failed_start);
else
- ASSERT(failed_start == NULL);
+ ASSERT(failed_start == NULL && failed_state == NULL);
again:
if (!prealloc && gfpflags_allow_blocking(mask)) {
/*
@@ -1012,6 +1033,7 @@ hit_next:
if (state->start == start && state->end <= end) {
if (state->state & exclusive_bits) {
*failed_start = state->start;
+ cache_state(state, failed_state);
err = -EEXIST;
goto out;
}
@@ -1047,6 +1069,7 @@ hit_next:
if (state->start < start) {
if (state->state & exclusive_bits) {
*failed_start = start;
+ cache_state(state, failed_state);
err = -EEXIST;
goto out;
}
@@ -1125,6 +1148,7 @@ hit_next:
if (state->start <= end && state->end > end) {
if (state->state & exclusive_bits) {
*failed_start = start;
+ cache_state(state, failed_state);
err = -EEXIST;
goto out;
}
@@ -1162,8 +1186,8 @@ out:
int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
u32 bits, struct extent_state **cached_state, gfp_t mask)
{
- return __set_extent_bit(tree, start, end, bits, NULL, cached_state,
- NULL, mask);
+ return __set_extent_bit(tree, start, end, bits, NULL, NULL,
+ cached_state, NULL, mask);
}
/*
@@ -1598,8 +1622,8 @@ int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
*/
ASSERT(!(bits & EXTENT_LOCKED));
- return __set_extent_bit(tree, start, end, bits, NULL, NULL, changeset,
- GFP_NOFS);
+ return __set_extent_bit(tree, start, end, bits, NULL, NULL, NULL,
+ changeset, GFP_NOFS);
}
int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
@@ -1622,7 +1646,7 @@ int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
u64 failed_start;
err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, &failed_start,
- cached, NULL, GFP_NOFS);
+ NULL, cached, NULL, GFP_NOFS);
if (err == -EEXIST) {
if (failed_start > start)
clear_extent_bit(tree, start, failed_start - 1,
@@ -1639,20 +1663,22 @@ int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
int lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
struct extent_state **cached_state)
{
+ struct extent_state *failed_state = NULL;
int err;
u64 failed_start;
err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, &failed_start,
- cached_state, NULL, GFP_NOFS);
+ &failed_state, cached_state, NULL, GFP_NOFS);
while (err == -EEXIST) {
if (failed_start != start)
clear_extent_bit(tree, start, failed_start - 1,
EXTENT_LOCKED, cached_state);
- wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
+ wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED,
+ &failed_state);
err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
- &failed_start, cached_state, NULL,
- GFP_NOFS);
+ &failed_start, &failed_state,
+ cached_state, NULL, GFP_NOFS);
}
return err;
}
diff --git a/fs/btrfs/extent-io-tree.h b/fs/btrfs/extent-io-tree.h
index 786be8f38f0b..c71aa29f719d 100644
--- a/fs/btrfs/extent-io-tree.h
+++ b/fs/btrfs/extent-io-tree.h
@@ -235,6 +235,7 @@ int find_contiguous_extent_bit(struct extent_io_tree *tree, u64 start,
bool btrfs_find_delalloc_range(struct extent_io_tree *tree, u64 *start,
u64 *end, u64 max_bytes,
struct extent_state **cached_state);
-void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, u32 bits);
+void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, u32 bits,
+ struct extent_state **cached_state);
#endif /* BTRFS_EXTENT_IO_TREE_H */
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index c7e94a0e60d5..836851233618 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -5001,7 +5001,8 @@ static int read_extent_buffer_subpage(struct extent_buffer *eb, int wait,
if (ret || wait != WAIT_COMPLETE)
return ret;
- wait_extent_bit(io_tree, eb->start, eb->start + eb->len - 1, EXTENT_LOCKED);
+ wait_extent_bit(io_tree, eb->start, eb->start + eb->len - 1,
+ EXTENT_LOCKED, NULL);
if (!test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
ret = -EIO;
return ret;
View Lorry Controller Status