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-rw-r--r--fs/btrfs/ctree.h4
-rw-r--r--fs/btrfs/disk-io.c4
-rw-r--r--fs/btrfs/extent_io.c122
-rw-r--r--fs/btrfs/tests/btrfs-tests.c22
4 files changed, 97 insertions, 55 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e0d3cf2ec0dd..a240e8b83709 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -994,10 +994,10 @@ struct btrfs_fs_info {
struct btrfs_delayed_root *delayed_root;
- /* Extent buffer xarray */
+ /* Extent buffer radix tree */
spinlock_t buffer_lock;
/* Entries are eb->start / sectorsize */
- struct xarray extent_buffers;
+ struct radix_tree_root buffer_radix;
/* next backup root to be overwritten */
int backup_root_index;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 88ba485b155b..f142ab43df36 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -486,7 +486,7 @@ static int csum_dirty_subpage_buffers(struct btrfs_fs_info *fs_info,
uptodate = btrfs_subpage_test_uptodate(fs_info, page, cur,
fs_info->nodesize);
- /* A dirty eb shouldn't disappear from extent_buffers */
+ /* A dirty eb shouldn't disappear from buffer_radix */
if (WARN_ON(!eb))
return -EUCLEAN;
@@ -3150,7 +3150,7 @@ static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
{
INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
- xa_init_flags(&fs_info->extent_buffers, GFP_ATOMIC);
+ INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
INIT_LIST_HEAD(&fs_info->trans_list);
INIT_LIST_HEAD(&fs_info->dead_roots);
INIT_LIST_HEAD(&fs_info->delayed_iputs);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 9c250b8cd548..31729b1be5f3 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2966,7 +2966,7 @@ static void begin_page_read(struct btrfs_fs_info *fs_info, struct page *page)
}
/*
- * Find extent buffer for a given bytenr.
+ * Find extent buffer for a givne bytenr.
*
* This is for end_bio_extent_readpage(), thus we can't do any unsafe locking
* in endio context.
@@ -2985,9 +2985,11 @@ static struct extent_buffer *find_extent_buffer_readpage(
return (struct extent_buffer *)page->private;
}
- /* For subpage case, we need to lookup extent buffer xarray */
- eb = xa_load(&fs_info->extent_buffers,
- bytenr >> fs_info->sectorsize_bits);
+ /* For subpage case, we need to lookup buffer radix tree */
+ rcu_read_lock();
+ eb = radix_tree_lookup(&fs_info->buffer_radix,
+ bytenr >> fs_info->sectorsize_bits);
+ rcu_read_unlock();
ASSERT(eb);
return eb;
}
@@ -4434,8 +4436,8 @@ static struct extent_buffer *find_extent_buffer_nolock(
struct extent_buffer *eb;
rcu_read_lock();
- eb = xa_load(&fs_info->extent_buffers,
- start >> fs_info->sectorsize_bits);
+ eb = radix_tree_lookup(&fs_info->buffer_radix,
+ start >> fs_info->sectorsize_bits);
if (eb && atomic_inc_not_zero(&eb->refs)) {
rcu_read_unlock();
return eb;
@@ -6128,22 +6130,24 @@ struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
if (!eb)
return ERR_PTR(-ENOMEM);
eb->fs_info = fs_info;
-
- do {
- ret = xa_insert(&fs_info->extent_buffers,
- start >> fs_info->sectorsize_bits,
- eb, GFP_NOFS);
- if (ret == -ENOMEM) {
- exists = ERR_PTR(ret);
+again:
+ ret = radix_tree_preload(GFP_NOFS);
+ if (ret) {
+ exists = ERR_PTR(ret);
+ goto free_eb;
+ }
+ spin_lock(&fs_info->buffer_lock);
+ ret = radix_tree_insert(&fs_info->buffer_radix,
+ start >> fs_info->sectorsize_bits, eb);
+ spin_unlock(&fs_info->buffer_lock);
+ radix_tree_preload_end();
+ if (ret == -EEXIST) {
+ exists = find_extent_buffer(fs_info, start);
+ if (exists)
goto free_eb;
- }
- if (ret == -EBUSY) {
- exists = find_extent_buffer(fs_info, start);
- if (exists)
- goto free_eb;
- }
- } while (ret);
-
+ else
+ goto again;
+ }
check_buffer_tree_ref(eb);
set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
@@ -6318,22 +6322,25 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
}
if (uptodate)
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
-
- do {
- ret = xa_insert(&fs_info->extent_buffers,
- start >> fs_info->sectorsize_bits,
- eb, GFP_NOFS);
- if (ret == -ENOMEM) {
- exists = ERR_PTR(ret);
+again:
+ ret = radix_tree_preload(GFP_NOFS);
+ if (ret) {
+ exists = ERR_PTR(ret);
+ goto free_eb;
+ }
+
+ spin_lock(&fs_info->buffer_lock);
+ ret = radix_tree_insert(&fs_info->buffer_radix,
+ start >> fs_info->sectorsize_bits, eb);
+ spin_unlock(&fs_info->buffer_lock);
+ radix_tree_preload_end();
+ if (ret == -EEXIST) {
+ exists = find_extent_buffer(fs_info, start);
+ if (exists)
goto free_eb;
- }
- if (ret == -EBUSY) {
- exists = find_extent_buffer(fs_info, start);
- if (exists)
- goto free_eb;
- }
- } while (ret);
-
+ else
+ goto again;
+ }
/* add one reference for the tree */
check_buffer_tree_ref(eb);
set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
@@ -6378,8 +6385,10 @@ static int release_extent_buffer(struct extent_buffer *eb)
spin_unlock(&eb->refs_lock);
- xa_erase(&fs_info->extent_buffers,
- eb->start >> fs_info->sectorsize_bits);
+ spin_lock(&fs_info->buffer_lock);
+ radix_tree_delete(&fs_info->buffer_radix,
+ eb->start >> fs_info->sectorsize_bits);
+ spin_unlock(&fs_info->buffer_lock);
} else {
spin_unlock(&eb->refs_lock);
}
@@ -7324,25 +7333,42 @@ void memmove_extent_buffer(const struct extent_buffer *dst,
}
}
+#define GANG_LOOKUP_SIZE 16
static struct extent_buffer *get_next_extent_buffer(
struct btrfs_fs_info *fs_info, struct page *page, u64 bytenr)
{
- struct extent_buffer *eb;
- unsigned long index;
+ struct extent_buffer *gang[GANG_LOOKUP_SIZE];
+ struct extent_buffer *found = NULL;
u64 page_start = page_offset(page);
+ u64 cur = page_start;
ASSERT(in_range(bytenr, page_start, PAGE_SIZE));
lockdep_assert_held(&fs_info->buffer_lock);
- xa_for_each_start(&fs_info->extent_buffers, index, eb,
- page_start >> fs_info->sectorsize_bits) {
- if (in_range(eb->start, page_start, PAGE_SIZE))
- return eb;
- else if (eb->start >= page_start + PAGE_SIZE)
- /* Already beyond page end */
- return NULL;
+ while (cur < page_start + PAGE_SIZE) {
+ int ret;
+ int i;
+
+ ret = radix_tree_gang_lookup(&fs_info->buffer_radix,
+ (void **)gang, cur >> fs_info->sectorsize_bits,
+ min_t(unsigned int, GANG_LOOKUP_SIZE,
+ PAGE_SIZE / fs_info->nodesize));
+ if (ret == 0)
+ goto out;
+ for (i = 0; i < ret; i++) {
+ /* Already beyond page end */
+ if (gang[i]->start >= page_start + PAGE_SIZE)
+ goto out;
+ /* Found one */
+ if (gang[i]->start >= bytenr) {
+ found = gang[i];
+ goto out;
+ }
+ }
+ cur = gang[ret - 1]->start + gang[ret - 1]->len;
}
- return NULL;
+out:
+ return found;
}
static int try_release_subpage_extent_buffer(struct page *page)
diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c
index c8c4efc9a3fb..d8e56edd6991 100644
--- a/fs/btrfs/tests/btrfs-tests.c
+++ b/fs/btrfs/tests/btrfs-tests.c
@@ -150,8 +150,8 @@ struct btrfs_fs_info *btrfs_alloc_dummy_fs_info(u32 nodesize, u32 sectorsize)
void btrfs_free_dummy_fs_info(struct btrfs_fs_info *fs_info)
{
- unsigned long index;
- struct extent_buffer *eb;
+ struct radix_tree_iter iter;
+ void **slot;
struct btrfs_device *dev, *tmp;
if (!fs_info)
@@ -163,9 +163,25 @@ void btrfs_free_dummy_fs_info(struct btrfs_fs_info *fs_info)
test_mnt->mnt_sb->s_fs_info = NULL;
- xa_for_each(&fs_info->extent_buffers, index, eb) {
+ spin_lock(&fs_info->buffer_lock);
+ radix_tree_for_each_slot(slot, &fs_info->buffer_radix, &iter, 0) {
+ struct extent_buffer *eb;
+
+ eb = radix_tree_deref_slot_protected(slot, &fs_info->buffer_lock);
+ if (!eb)
+ continue;
+ /* Shouldn't happen but that kind of thinking creates CVE's */
+ if (radix_tree_exception(eb)) {
+ if (radix_tree_deref_retry(eb))
+ slot = radix_tree_iter_retry(&iter);
+ continue;
+ }
+ slot = radix_tree_iter_resume(slot, &iter);
+ spin_unlock(&fs_info->buffer_lock);
free_extent_buffer_stale(eb);
+ spin_lock(&fs_info->buffer_lock);
}
+ spin_unlock(&fs_info->buffer_lock);
btrfs_mapping_tree_free(&fs_info->mapping_tree);
list_for_each_entry_safe(dev, tmp, &fs_info->fs_devices->devices,
generated by cgit (git 2.34.1) at 2024-06-27 15:08:18 +0000