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path: root/fs/btrfs/free-space-cache.c
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-rw-r--r--fs/btrfs/free-space-cache.c67
1 files changed, 47 insertions, 20 deletions
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index ef3bea7bb257..4f419bafd071 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -1433,13 +1433,19 @@ static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
ctl->free_space += bytes;
}
+/*
+ * If we can not find suitable extent, we will use bytes to record
+ * the size of the max extent.
+ */
static int search_bitmap(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *bitmap_info, u64 *offset,
u64 *bytes)
{
unsigned long found_bits = 0;
+ unsigned long max_bits = 0;
unsigned long bits, i;
unsigned long next_zero;
+ unsigned long extent_bits;
i = offset_to_bit(bitmap_info->offset, ctl->unit,
max_t(u64, *offset, bitmap_info->offset));
@@ -1448,9 +1454,12 @@ static int search_bitmap(struct btrfs_free_space_ctl *ctl,
for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
next_zero = find_next_zero_bit(bitmap_info->bitmap,
BITS_PER_BITMAP, i);
- if ((next_zero - i) >= bits) {
- found_bits = next_zero - i;
+ extent_bits = next_zero - i;
+ if (extent_bits >= bits) {
+ found_bits = extent_bits;
break;
+ } else if (extent_bits > max_bits) {
+ max_bits = extent_bits;
}
i = next_zero;
}
@@ -1461,38 +1470,41 @@ static int search_bitmap(struct btrfs_free_space_ctl *ctl,
return 0;
}
+ *bytes = (u64)(max_bits) * ctl->unit;
return -1;
}
+/* Cache the size of the max extent in bytes */
static struct btrfs_free_space *
find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
- unsigned long align)
+ unsigned long align, u64 *max_extent_size)
{
struct btrfs_free_space *entry;
struct rb_node *node;
- u64 ctl_off;
u64 tmp;
u64 align_off;
int ret;
if (!ctl->free_space_offset.rb_node)
- return NULL;
+ goto out;
entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
if (!entry)
- return NULL;
+ goto out;
for (node = &entry->offset_index; node; node = rb_next(node)) {
entry = rb_entry(node, struct btrfs_free_space, offset_index);
- if (entry->bytes < *bytes)
+ if (entry->bytes < *bytes) {
+ if (entry->bytes > *max_extent_size)
+ *max_extent_size = entry->bytes;
continue;
+ }
/* make sure the space returned is big enough
* to match our requested alignment
*/
if (*bytes >= align) {
- ctl_off = entry->offset - ctl->start;
- tmp = ctl_off + align - 1;;
+ tmp = entry->offset - ctl->start + align - 1;
do_div(tmp, align);
tmp = tmp * align + ctl->start;
align_off = tmp - entry->offset;
@@ -1501,14 +1513,22 @@ find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
tmp = entry->offset;
}
- if (entry->bytes < *bytes + align_off)
+ if (entry->bytes < *bytes + align_off) {
+ if (entry->bytes > *max_extent_size)
+ *max_extent_size = entry->bytes;
continue;
+ }
if (entry->bitmap) {
- ret = search_bitmap(ctl, entry, &tmp, bytes);
+ u64 size = *bytes;
+
+ ret = search_bitmap(ctl, entry, &tmp, &size);
if (!ret) {
*offset = tmp;
+ *bytes = size;
return entry;
+ } else if (size > *max_extent_size) {
+ *max_extent_size = size;
}
continue;
}
@@ -1517,7 +1537,7 @@ find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
*bytes = entry->bytes - align_off;
return entry;
}
-
+out:
return NULL;
}
@@ -2118,7 +2138,8 @@ void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
}
u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
- u64 offset, u64 bytes, u64 empty_size)
+ u64 offset, u64 bytes, u64 empty_size,
+ u64 *max_extent_size)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *entry = NULL;
@@ -2129,7 +2150,7 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
spin_lock(&ctl->tree_lock);
entry = find_free_space(ctl, &offset, &bytes_search,
- block_group->full_stripe_len);
+ block_group->full_stripe_len, max_extent_size);
if (!entry)
goto out;
@@ -2139,7 +2160,6 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
if (!entry->bytes)
free_bitmap(ctl, entry);
} else {
-
unlink_free_space(ctl, entry);
align_gap_len = offset - entry->offset;
align_gap = entry->offset;
@@ -2153,7 +2173,6 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
else
link_free_space(ctl, entry);
}
-
out:
spin_unlock(&ctl->tree_lock);
@@ -2208,7 +2227,8 @@ int btrfs_return_cluster_to_free_space(
static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
struct btrfs_free_space *entry,
- u64 bytes, u64 min_start)
+ u64 bytes, u64 min_start,
+ u64 *max_extent_size)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
int err;
@@ -2220,8 +2240,11 @@ static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
search_bytes = bytes;
err = search_bitmap(ctl, entry, &search_start, &search_bytes);
- if (err)
+ if (err) {
+ if (search_bytes > *max_extent_size)
+ *max_extent_size = search_bytes;
return 0;
+ }
ret = search_start;
__bitmap_clear_bits(ctl, entry, ret, bytes);
@@ -2236,7 +2259,7 @@ static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
*/
u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster, u64 bytes,
- u64 min_start)
+ u64 min_start, u64 *max_extent_size)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *entry = NULL;
@@ -2256,6 +2279,9 @@ u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
entry = rb_entry(node, struct btrfs_free_space, offset_index);
while(1) {
+ if (entry->bytes < bytes && entry->bytes > *max_extent_size)
+ *max_extent_size = entry->bytes;
+
if (entry->bytes < bytes ||
(!entry->bitmap && entry->offset < min_start)) {
node = rb_next(&entry->offset_index);
@@ -2269,7 +2295,8 @@ u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
if (entry->bitmap) {
ret = btrfs_alloc_from_bitmap(block_group,
cluster, entry, bytes,
- cluster->window_start);
+ cluster->window_start,
+ max_extent_size);
if (ret == 0) {
node = rb_next(&entry->offset_index);
if (!node)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.