From: Chandra Seetharaman <sekha...@us.ibm.com>
In order to handle multiple extent buffers per page, first we need to create a
way to handle all the extent buffers that are attached to a page.
This patch creates a new data structure 'struct extent_buffer_head', and moves
fields that are common to all extent buffers in a page from 'struct extent
buffer' to 'struct extent_buffer_head'
Also, this patch moves EXTENT_BUFFER_TREE_REF, EXTENT_BUFFER_DUMMY and
EXTENT_BUFFER_IN_TREE flags from extent_buffer->ebflags to
extent_buffer_head->bflags.
Signed-off-by: Chandra Seetharaman <sekha...@us.ibm.com>
Signed-off-by: Chandan Rajendra <chan...@linux.vnet.ibm.com>
---
fs/btrfs/backref.c | 2 +-
fs/btrfs/ctree.c | 2 +-
fs/btrfs/ctree.h | 6 +-
fs/btrfs/disk-io.c | 46 ++++--
fs/btrfs/extent-tree.c | 6 +-
fs/btrfs/extent_io.c | 372 +++++++++++++++++++++++++++++--------------
fs/btrfs/extent_io.h | 46 ++++--
fs/btrfs/volumes.c | 2 +-
include/trace/events/btrfs.h | 2 +-
9 files changed, 326 insertions(+), 158 deletions(-)
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index a88da72..603ae44 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1272,7 +1272,7 @@ char *btrfs_ref_to_path(struct btrfs_root *fs_root,
struct btrfs_path *path,
eb = path->nodes[0];
/* make sure we can use eb after releasing the path */
if (eb != eb_in) {
- atomic_inc(&eb->refs);
+ atomic_inc(&eb_head(eb)->refs);
btrfs_tree_read_lock(eb);
btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
}
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index cbd3a7d..0d4ad91 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -169,7 +169,7 @@ struct extent_buffer *btrfs_root_node(struct btrfs_root
*root)
* the inc_not_zero dance and if it doesn't work then
* synchronize_rcu and try again.
*/
- if (atomic_inc_not_zero(&eb->refs)) {
+ if (atomic_inc_not_zero(&eb_head(eb)->refs)) {
rcu_read_unlock();
break;
}
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index dac6653..901ada2 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2138,14 +2138,16 @@ static inline void btrfs_set_token_##name(struct
extent_buffer *eb, \
#define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits) \
static inline u##bits btrfs_##name(struct extent_buffer *eb) \
{ \
- type *p = page_address(eb->pages[0]); \
+ type *p = page_address(eb_head(eb)->pages[0]) + \
+ (eb->start & (PAGE_CACHE_SIZE -1)); \
u##bits res = le##bits##_to_cpu(p->member); \
return res; \
} \
static inline void btrfs_set_##name(struct extent_buffer *eb, \
u##bits val) \
{ \
- type *p = page_address(eb->pages[0]); \
+ type *p = page_address(eb_head(eb)->pages[0]) + \
+ (eb->start & (PAGE_CACHE_SIZE -1)); \
p->member = cpu_to_le##bits(val); \
}
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index cc1b423..bda2157 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1018,13 +1018,21 @@ static int btree_set_page_dirty(struct page *page)
{
#ifdef DEBUG
struct extent_buffer *eb;
+ int i, dirty = 0;
BUG_ON(!PagePrivate(page));
eb = (struct extent_buffer *)page->private;
BUG_ON(!eb);
- BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
- BUG_ON(!atomic_read(&eb->refs));
- btrfs_assert_tree_locked(eb);
+
+ do {
+ dirty = test_bit(EXTENT_BUFFER_DIRTY, &eb->ebflags);
+ if (dirty)
+ break;
+ } while ((eb = eb->eb_next) != NULL);
+
+ BUG_ON(!dirty);
+ BUG_ON(!atomic_read(&(eb_head(eb)->refs)));
+ btrfs_assert_tree_locked(&ebh->eb);
#endif
return __set_page_dirty_nobuffers(page);
}
@@ -1068,7 +1076,7 @@ int reada_tree_block_flagged(struct btrfs_root *root, u64
bytenr, u32 blocksize,
if (!buf)
return 0;
- set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
+ set_bit(EXTENT_BUFFER_READAHEAD, &buf->ebflags);
ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
btree_get_extent, mirror_num);
@@ -1077,7 +1085,7 @@ int reada_tree_block_flagged(struct btrfs_root *root, u64
bytenr, u32 blocksize,
return ret;
}
- if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
+ if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->ebflags)) {
free_extent_buffer(buf);
return -EIO;
} else if (extent_buffer_uptodate(buf)) {
@@ -1103,14 +1111,16 @@ struct extent_buffer
*btrfs_find_create_tree_block(struct btrfs_root *root,
int btrfs_write_tree_block(struct extent_buffer *buf)
{
- return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
+ return filemap_fdatawrite_range(eb_head(buf)->pages[0]->mapping,
+ buf->start,
buf->start + buf->len - 1);
}
int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
{
- return filemap_fdatawait_range(buf->pages[0]->mapping,
- buf->start, buf->start + buf->len - 1);
+ return filemap_fdatawait_range(eb_head(buf)->pages[0]->mapping,
+ buf->start,
+ buf->start + buf->len - 1);
}
struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
@@ -1141,7 +1151,8 @@ void clean_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
fs_info->running_transaction->transid) {
btrfs_assert_tree_locked(buf);
- if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
+ if (test_and_clear_bit(EXTENT_BUFFER_DIRTY,
+ &buf->ebflags)) {
__percpu_counter_add(&fs_info->dirty_metadata_bytes,
-buf->len,
fs_info->dirty_metadata_batch);
@@ -2613,7 +2624,8 @@ int open_ctree(struct super_block *sb,
btrfs_super_chunk_root(disk_super),
blocksize, generation);
if (!chunk_root->node ||
- !test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
+ !test_bit(EXTENT_BUFFER_UPTODATE,
+ &chunk_root->node->ebflags)) {
printk(KERN_WARNING "BTRFS: failed to read chunk root on %s\n",
sb->s_id);
goto fail_tree_roots;
@@ -2652,7 +2664,8 @@ retry_root_backup:
btrfs_super_root(disk_super),
blocksize, generation);
if (!tree_root->node ||
- !test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
+ !test_bit(EXTENT_BUFFER_UPTODATE,
+ &tree_root->node->ebflags)) {
printk(KERN_WARNING "BTRFS: failed to read tree root on %s\n",
sb->s_id);
@@ -3642,7 +3655,7 @@ int btrfs_buffer_uptodate(struct extent_buffer *buf, u64
parent_transid,
int atomic)
{
int ret;
- struct inode *btree_inode = buf->pages[0]->mapping->host;
+ struct inode *btree_inode = eb_head(buf)->pages[0]->mapping->host;
ret = extent_buffer_uptodate(buf);
if (!ret)
@@ -3672,10 +3685,10 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
* enabled. Normal people shouldn't be marking dummy buffers as dirty
* outside of the sanity tests.
*/
- if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &buf->bflags)))
+ if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb_head(buf)->bflags)))
return;
#endif
- root = BTRFS_I(buf->pages[0]->mapping->host)->root;
+ root = BTRFS_I(eb_head(buf)->pages[0]->mapping->host)->root;
btrfs_assert_tree_locked(buf);
if (transid != root->fs_info->generation)
WARN(1, KERN_CRIT "btrfs transid mismatch buffer %llu, "
@@ -3724,7 +3737,8 @@ void btrfs_btree_balance_dirty_nodelay(struct btrfs_root
*root)
int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
{
- struct btrfs_root *root = BTRFS_I(buf->pages[0]->mapping->host)->root;
+ struct btrfs_root *root =
+ BTRFS_I(eb_head(buf)->pages[0]->mapping->host)->root;
return btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
}
@@ -3962,7 +3976,7 @@ static int btrfs_destroy_marked_extents(struct btrfs_root
*root,
wait_on_extent_buffer_writeback(eb);
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY,
- &eb->bflags))
+ &eb->ebflags))
clear_extent_buffer_dirty(eb);
free_extent_buffer_stale(eb);
}
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 32312e0..232d0a3 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5984,7 +5984,7 @@ void btrfs_free_tree_block(struct btrfs_trans_handle
*trans,
goto out;
}
- WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
+ WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->ebflags));
btrfs_add_free_space(cache, buf->start, buf->len);
btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE);
@@ -6001,7 +6001,7 @@ out:
* Deleting the buffer, clear the corrupt flag since it doesn't matter
* anymore.
*/
- clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
+ clear_bit(EXTENT_BUFFER_CORRUPT, &buf->ebflags);
btrfs_put_block_group(cache);
}
@@ -6887,7 +6887,7 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
btrfs_tree_lock(buf);
clean_tree_block(trans, root, buf);
- clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
+ clear_bit(EXTENT_BUFFER_STALE, &buf->ebflags);
btrfs_set_lock_blocking(buf);
btrfs_set_buffer_uptodate(buf);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 17ff01b..5bc7b9b 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -56,6 +56,7 @@ void btrfs_leak_debug_check(void)
{
struct extent_state *state;
struct extent_buffer *eb;
+ struct extent_buffer_head *ebh;
while (!list_empty(&states)) {
state = list_entry(states.next, struct extent_state, leak_list);
@@ -68,12 +69,17 @@ void btrfs_leak_debug_check(void)
}
while (!list_empty(&buffers)) {
- eb = list_entry(buffers.next, struct extent_buffer, leak_list);
- printk(KERN_ERR "BTRFS: buffer leak start %llu len %lu "
- "refs %d\n",
- eb->start, eb->len, atomic_read(&eb->refs));
- list_del(&eb->leak_list);
- kmem_cache_free(extent_buffer_cache, eb);
+ ebh = list_entry(buffers.next, struct extent_buffer_head,
leak_list);
+ printk(KERN_ERR "btrfs buffer leak ");
+
+ eb = &ebh->eb;
+ do {
+ printk(KERN_ERR "eb %p %llu:%lu ", eb, eb->start,
eb->len);
+ } while ((eb = eb->eb_next) != NULL);
+
+ printk(KERN_ERR "refs %d\n", atomic_read(&ebh->refs));
+ list_del(&ebh->leak_list);
+ kmem_cache_free(extent_buffer_cache, ebh);
}
}
@@ -144,7 +150,7 @@ int __init extent_io_init(void)
return -ENOMEM;
extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
- sizeof(struct extent_buffer), 0,
+ sizeof(struct extent_buffer_head), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!extent_buffer_cache)
goto free_state_cache;
@@ -3484,7 +3490,7 @@ static int eb_wait(void *word)
void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
{
- wait_on_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK, eb_wait,
+ wait_on_bit(&eb->ebflags, EXTENT_BUFFER_WRITEBACK, eb_wait,
TASK_UNINTERRUPTIBLE);
}
@@ -4410,29 +4416,47 @@ out:
return ret;
}
-static void __free_extent_buffer(struct extent_buffer *eb)
+static void __free_extent_buffer(struct extent_buffer_head *ebh)
{
- btrfs_leak_debug_del(&eb->leak_list);
- kmem_cache_free(extent_buffer_cache, eb);
+ struct extent_buffer *eb, *next_eb;
+
+ btrfs_leak_debug_del(&ebh->leak_list);
+
+ eb = ebh->eb.eb_next;
+ while (eb) {
+ next_eb = eb->eb_next;
+ kfree(eb);
+ eb = next_eb;
+ }
+
+ kmem_cache_free(extent_buffer_cache, ebh);
}
static int extent_buffer_under_io(struct extent_buffer *eb)
{
- return (atomic_read(&eb->io_pages) ||
- test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
- test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
+ struct extent_buffer_head *ebh = eb->ebh;
+ int dirty_or_writeback = 0;
+
+ for (eb = &ebh->eb; eb; eb = eb->eb_next) {
+ if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->ebflags)
+ || test_bit(EXTENT_BUFFER_DIRTY, &eb->ebflags))
+ dirty_or_writeback = 1;
+ }
+
+ return (atomic_read(&ebh->io_bvecs) || dirty_or_writeback);
}
/*
* Helper for releasing extent buffer page.
*/
-static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
+static noinline void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
unsigned long start_idx)
{
unsigned long index;
unsigned long num_pages;
struct page *page;
- int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
+ struct extent_buffer_head *ebh = eb_head(eb);
+ int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &ebh->bflags);
BUG_ON(extent_buffer_under_io(eb));
@@ -4442,6 +4466,8 @@ static void btrfs_release_extent_buffer_page(struct
extent_buffer *eb,
return;
do {
+ struct extent_buffer *e;
+
index--;
page = extent_buffer_page(eb, index);
if (page && mapped) {
@@ -4454,8 +4480,10 @@ static void btrfs_release_extent_buffer_page(struct
extent_buffer *eb,
* this eb.
*/
if (PagePrivate(page) &&
- page->private == (unsigned long)eb) {
- BUG_ON(test_bit(EXTENT_BUFFER_DIRTY,
&eb->bflags));
+ page->private == (unsigned long)(&ebh->eb)) {
+ for (e = &ebh->eb; !e; e = e->eb_next)
+ BUG_ON(test_bit(EXTENT_BUFFER_DIRTY,
+ &e->ebflags));
BUG_ON(PageDirty(page));
BUG_ON(PageWriteback(page));
/*
@@ -4483,22 +4511,18 @@ static void btrfs_release_extent_buffer_page(struct
extent_buffer *eb,
static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
{
btrfs_release_extent_buffer_page(eb, 0);
- __free_extent_buffer(eb);
+ __free_extent_buffer(eb_head(eb));
}
-static struct extent_buffer *
-__alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
- unsigned long len, gfp_t mask)
+static void __init_extent_buffer(struct extent_buffer *eb,
+ struct extent_buffer_head *ebh,
+ u64 start,
+ unsigned long len)
{
- struct extent_buffer *eb = NULL;
-
- eb = kmem_cache_zalloc(extent_buffer_cache, mask);
- if (eb == NULL)
- return NULL;
eb->start = start;
eb->len = len;
- eb->fs_info = fs_info;
- eb->bflags = 0;
+ eb->ebh = ebh;
+ eb->eb_next = NULL;
rwlock_init(&eb->lock);
atomic_set(&eb->write_locks, 0);
atomic_set(&eb->read_locks, 0);
@@ -4509,12 +4533,26 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info,
u64 start,
eb->lock_nested = 0;
init_waitqueue_head(&eb->write_lock_wq);
init_waitqueue_head(&eb->read_lock_wq);
+}
+
+static struct extent_buffer *__alloc_extent_buffer(struct btrfs_fs_info
*fs_info,
+ u64 start, unsigned long len,
+ gfp_t mask)
+{
+ struct extent_buffer_head *ebh = NULL;
+ struct extent_buffer *eb = NULL;
+ int i;
- btrfs_leak_debug_add(&eb->leak_list, &buffers);
+ ebh = kmem_cache_zalloc(extent_buffer_cache, mask);
+ if (ebh == NULL)
+ return NULL;
+ ebh->fs_info = fs_info;
+ ebh->bflags = 0;
+ btrfs_leak_debug_add(&ebh->leak_list, &buffers);
- spin_lock_init(&eb->refs_lock);
- atomic_set(&eb->refs, 1);
- atomic_set(&eb->io_pages, 0);
+ spin_lock_init(&ebh->refs_lock);
+ atomic_set(&ebh->refs, 1);
+ atomic_set(&ebh->io_bvecs, 0);
/*
* Sanity checks, currently the maximum is 64k covered by 16x 4k pages
@@ -4523,6 +4561,29 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64
start,
> MAX_INLINE_EXTENT_BUFFER_SIZE);
BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
+ if (len < PAGE_CACHE_SIZE) {
+ struct extent_buffer *cur_eb, *prev_eb;
+ int ebs_per_page = PAGE_CACHE_SIZE / len;
+ u64 st = start & ~(PAGE_CACHE_SIZE - 1);
+
+ prev_eb = NULL;
+ cur_eb = &ebh->eb;
+ for (i = 0; i < ebs_per_page; i++, st += len) {
+ if (prev_eb) {
+ cur_eb = kzalloc(sizeof(*eb), mask);
+ prev_eb->eb_next = cur_eb;
+ }
+ __init_extent_buffer(cur_eb, ebh, st, len);
+ prev_eb = cur_eb;
+ if (st == start)
+ eb = cur_eb;
+ }
+ BUG_ON(!eb);
+ } else {
+ eb = &ebh->eb;
+ __init_extent_buffer(eb, ebh, start, len);
+ }
+
return eb;
}
@@ -4543,15 +4604,16 @@ struct extent_buffer *btrfs_clone_extent_buffer(struct
extent_buffer *src)
btrfs_release_extent_buffer(new);
return NULL;
}
- attach_extent_buffer_page(new, p);
+ attach_extent_buffer_page(&(eb_head(new)->eb), p);
WARN_ON(PageDirty(p));
SetPageUptodate(p);
- new->pages[i] = p;
+ eb_head(new)->pages[i] = p;
}
+ set_bit(EXTENT_BUFFER_UPTODATE, &new->ebflags);
+ set_bit(EXTENT_BUFFER_DUMMY, &eb_head(new)->bflags);
+
copy_extent_buffer(new, src, 0, 0, src->len);
- set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags);
- set_bit(EXTENT_BUFFER_DUMMY, &new->bflags);
return new;
}
@@ -4567,19 +4629,19 @@ struct extent_buffer *alloc_dummy_extent_buffer(u64
start, unsigned long len)
return NULL;
for (i = 0; i < num_pages; i++) {
- eb->pages[i] = alloc_page(GFP_NOFS);
- if (!eb->pages[i])
+ eb_head(eb)->pages[i] = alloc_page(GFP_NOFS);
+ if (!eb_head(eb)->pages[i])
goto err;
}
set_extent_buffer_uptodate(eb);
btrfs_set_header_nritems(eb, 0);
- set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
+ set_bit(EXTENT_BUFFER_DUMMY, &eb_head(eb)->bflags);
return eb;
err:
for (; i > 0; i--)
- __free_page(eb->pages[i - 1]);
- __free_extent_buffer(eb);
+ __free_page(eb_head(eb)->pages[i - 1]);
+ __free_extent_buffer(eb_head(eb));
return NULL;
}
@@ -4606,14 +4668,15 @@ static void check_buffer_tree_ref(struct extent_buffer
*eb)
* So bump the ref count first, then set the bit. If someone
* beat us to it, drop the ref we added.
*/
- refs = atomic_read(&eb->refs);
- if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
+ refs = atomic_read(&eb_head(eb)->refs);
+ if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF,
+ &eb_head(eb)->bflags))
return;
- spin_lock(&eb->refs_lock);
- if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
- atomic_inc(&eb->refs);
- spin_unlock(&eb->refs_lock);
+ spin_lock(&eb_head(eb)->refs_lock);
+ if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb_head(eb)->bflags))
+ atomic_inc(&eb_head(eb)->refs);
+ spin_unlock(&eb_head(eb)->refs_lock);
}
static void mark_extent_buffer_accessed(struct extent_buffer *eb)
@@ -4632,15 +4695,24 @@ static void mark_extent_buffer_accessed(struct
extent_buffer *eb)
struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
u64 start)
{
+ struct extent_buffer_head *ebh;
struct extent_buffer *eb;
rcu_read_lock();
- eb = radix_tree_lookup(&fs_info->buffer_radix,
- start >> PAGE_CACHE_SHIFT);
- if (eb && atomic_inc_not_zero(&eb->refs)) {
+ ebh = radix_tree_lookup(&fs_info->buffer_radix,
+ start >> PAGE_CACHE_SHIFT);
+ if (ebh && atomic_inc_not_zero(&ebh->refs)) {
rcu_read_unlock();
- mark_extent_buffer_accessed(eb);
- return eb;
+
+ eb = &ebh->eb;
+ do {
+ if (eb->start == start) {
+ mark_extent_buffer_accessed(eb);
+ return eb;
+ }
+ } while ((eb = eb->eb_next) != NULL);
+
+ BUG();
}
rcu_read_unlock();
@@ -4653,7 +4725,7 @@ struct extent_buffer *alloc_extent_buffer(struct
btrfs_fs_info *fs_info,
unsigned long num_pages = num_extent_pages(start, len);
unsigned long i;
unsigned long index = start >> PAGE_CACHE_SHIFT;
- struct extent_buffer *eb;
+ struct extent_buffer *eb, *cur_eb;
struct extent_buffer *exists = NULL;
struct page *p;
struct address_space *mapping = fs_info->btree_inode->i_mapping;
@@ -4683,12 +4755,18 @@ struct extent_buffer *alloc_extent_buffer(struct
btrfs_fs_info *fs_info,
* overwrite page->private.
*/
exists = (struct extent_buffer *)p->private;
- if (atomic_inc_not_zero(&exists->refs)) {
+ if (atomic_inc_not_zero(&eb_head(exists)->refs)) {
spin_unlock(&mapping->private_lock);
unlock_page(p);
page_cache_release(p);
- mark_extent_buffer_accessed(exists);
- goto free_eb;
+ do {
+ if (exists->start == start) {
+
mark_extent_buffer_accessed(exists);
+ goto free_eb;
+ }
+ } while ((exists = exists->eb_next) != NULL);
+
+ BUG();
}
/*
@@ -4699,11 +4777,11 @@ struct extent_buffer *alloc_extent_buffer(struct
btrfs_fs_info *fs_info,
WARN_ON(PageDirty(p));
page_cache_release(p);
}
- attach_extent_buffer_page(eb, p);
+ attach_extent_buffer_page(&(eb_head(eb)->eb), p);
spin_unlock(&mapping->private_lock);
WARN_ON(PageDirty(p));
mark_page_accessed(p);
- eb->pages[i] = p;
+ eb_head(eb)->pages[i] = p;
if (!PageUptodate(p))
uptodate = 0;
@@ -4712,16 +4790,22 @@ struct extent_buffer *alloc_extent_buffer(struct
btrfs_fs_info *fs_info,
* and why we unlock later
*/
}
- if (uptodate)
- set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
+ if (uptodate) {
+ cur_eb = &(eb_head(eb)->eb);
+ do {
+ set_bit(EXTENT_BUFFER_UPTODATE, &cur_eb->ebflags);
+ } while ((cur_eb = cur_eb->eb_next) != NULL);
+ }
again:
ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
- if (ret)
+ if (ret) {
+ exists = NULL;
goto free_eb;
+ }
spin_lock(&fs_info->buffer_lock);
ret = radix_tree_insert(&fs_info->buffer_radix,
- start >> PAGE_CACHE_SHIFT, eb);
+ start >> PAGE_CACHE_SHIFT, eb_head(eb));
spin_unlock(&fs_info->buffer_lock);
radix_tree_preload_end();
if (ret == -EEXIST) {
@@ -4733,7 +4817,7 @@ again:
}
/* add one reference for the tree */
check_buffer_tree_ref(eb);
- set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
+ set_bit(EXTENT_BUFFER_IN_TREE, &eb_head(eb)->bflags);
/*
* there is a race where release page may have
@@ -4744,108 +4828,125 @@ again:
* after the extent buffer is in the radix tree so
* it doesn't get lost
*/
- SetPageChecked(eb->pages[0]);
+ SetPageChecked(eb_head(eb)->pages[0]);
for (i = 1; i < num_pages; i++) {
p = extent_buffer_page(eb, i);
ClearPageChecked(p);
unlock_page(p);
}
- unlock_page(eb->pages[0]);
+ unlock_page(eb_head(eb)->pages[0]);
return eb;
free_eb:
for (i = 0; i < num_pages; i++) {
- if (eb->pages[i])
- unlock_page(eb->pages[i]);
+ if (eb_head(eb)->pages[i])
+ unlock_page(eb_head(eb)->pages[i]);
}
- WARN_ON(!atomic_dec_and_test(&eb->refs));
+ WARN_ON(!atomic_dec_and_test(&eb_head(eb)->refs));
btrfs_release_extent_buffer(eb);
return exists;
}
static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
{
- struct extent_buffer *eb =
- container_of(head, struct extent_buffer, rcu_head);
+ struct extent_buffer_head *ebh =
+ container_of(head, struct extent_buffer_head, rcu_head);
- __free_extent_buffer(eb);
+ __free_extent_buffer(ebh);
}
/* Expects to have eb->eb_lock already held */
-static int release_extent_buffer(struct extent_buffer *eb)
+static int release_extent_buffer(struct extent_buffer_head *ebh)
{
- WARN_ON(atomic_read(&eb->refs) == 0);
- if (atomic_dec_and_test(&eb->refs)) {
- if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
- struct btrfs_fs_info *fs_info = eb->fs_info;
+ WARN_ON(atomic_read(&ebh->refs) == 0);
+ if (atomic_dec_and_test(&ebh->refs)) {
+ if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &ebh->bflags)) {
+ struct btrfs_fs_info *fs_info = ebh->fs_info;
- spin_unlock(&eb->refs_lock);
+ spin_unlock(&ebh->refs_lock);
spin_lock(&fs_info->buffer_lock);
radix_tree_delete(&fs_info->buffer_radix,
- eb->start >> PAGE_CACHE_SHIFT);
+ ebh->eb.start >> PAGE_CACHE_SHIFT);
spin_unlock(&fs_info->buffer_lock);
} else {
- spin_unlock(&eb->refs_lock);
+ spin_unlock(&ebh->refs_lock);
}
/* Should be safe to release our pages at this point */
- btrfs_release_extent_buffer_page(eb, 0);
- call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
+ btrfs_release_extent_buffer_page(&ebh->eb, 0);
+ call_rcu(&ebh->rcu_head, btrfs_release_extent_buffer_rcu);
return 1;
}
- spin_unlock(&eb->refs_lock);
+ spin_unlock(&ebh->refs_lock);
return 0;
}
void free_extent_buffer(struct extent_buffer *eb)
{
+ struct extent_buffer_head *ebh;
int refs;
int old;
if (!eb)
return;
+ ebh = eb_head(eb);
while (1) {
- refs = atomic_read(&eb->refs);
+ refs = atomic_read(&ebh->refs);
if (refs <= 3)
break;
- old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
+ old = atomic_cmpxchg(&ebh->refs, refs, refs - 1);
if (old == refs)
return;
}
- spin_lock(&eb->refs_lock);
- if (atomic_read(&eb->refs) == 2 &&
- test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))
- atomic_dec(&eb->refs);
+ spin_lock(&ebh->refs_lock);
+ if (atomic_read(&ebh->refs) == 2 &&
+ test_bit(EXTENT_BUFFER_DUMMY, &ebh->bflags))
+ atomic_dec(&ebh->refs);
- if (atomic_read(&eb->refs) == 2 &&
- test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
+ if (atomic_read(&ebh->refs) == 2 &&
+ test_bit(EXTENT_BUFFER_STALE, &eb->ebflags) &&
!extent_buffer_under_io(eb) &&
- test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
- atomic_dec(&eb->refs);
+ test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &ebh->bflags))
+ atomic_dec(&ebh->refs);
/*
* I know this is terrible, but it's temporary until we stop tracking
* the uptodate bits and such for the extent buffers.
*/
- release_extent_buffer(eb);
+ release_extent_buffer(ebh);
}
void free_extent_buffer_stale(struct extent_buffer *eb)
{
+ struct extent_buffer_head *ebh;
if (!eb)
return;
- spin_lock(&eb->refs_lock);
- set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
+ ebh = eb_head(eb);
+ spin_lock(&ebh->refs_lock);
+
+ set_bit(EXTENT_BUFFER_STALE, &eb->ebflags);
+ if (atomic_read(&ebh->refs) == 2 && !extent_buffer_under_io(eb) &&
+ test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &ebh->bflags))
+ atomic_dec(&ebh->refs);
+
+ release_extent_buffer(ebh);
+}
+
+static int page_ebs_clean(struct extent_buffer_head *ebh)
+{
+ struct extent_buffer *eb = &ebh->eb;;
+
+ do {
+ if (test_bit(EXTENT_BUFFER_DIRTY, &eb->ebflags))
+ return 0;
+ } while ((eb = eb->eb_next) != NULL);
- if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
- test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
- atomic_dec(&eb->refs);
- release_extent_buffer(eb);
+ return 1;
}
void clear_extent_buffer_dirty(struct extent_buffer *eb)
@@ -4856,6 +4957,9 @@ void clear_extent_buffer_dirty(struct extent_buffer *eb)
num_pages = num_extent_pages(eb->start, eb->len);
+ if (eb->len < PAGE_CACHE_SIZE && !page_ebs_clean(eb_head(eb)))
+ return;
+
for (i = 0; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
if (!PageDirty(page))
@@ -4875,7 +4979,7 @@ void clear_extent_buffer_dirty(struct extent_buffer *eb)
ClearPageError(page);
unlock_page(page);
}
- WARN_ON(atomic_read(&eb->refs) == 0);
+ WARN_ON(atomic_read(&eb_head(eb)->refs) == 0);
}
int set_extent_buffer_dirty(struct extent_buffer *eb)
@@ -4886,11 +4990,11 @@ int set_extent_buffer_dirty(struct extent_buffer *eb)
check_buffer_tree_ref(eb);
- was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
+ was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->ebflags);
num_pages = num_extent_pages(eb->start, eb->len);
- WARN_ON(atomic_read(&eb->refs) == 0);
- WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
+ WARN_ON(atomic_read(&eb_head(eb)->refs) == 0);
+ WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb_head(eb)->bflags));
for (i = 0; i < num_pages; i++)
set_page_dirty(extent_buffer_page(eb, i));
@@ -4903,7 +5007,9 @@ int clear_extent_buffer_uptodate(struct extent_buffer *eb)
struct page *page;
unsigned long num_pages;
- clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
+ if (!eb || !eb_head(eb))
+ return 0;
+ clear_bit(EXTENT_BUFFER_UPTODATE, &eb->ebflags);
num_pages = num_extent_pages(eb->start, eb->len);
for (i = 0; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
@@ -4915,22 +5021,43 @@ int clear_extent_buffer_uptodate(struct extent_buffer
*eb)
int set_extent_buffer_uptodate(struct extent_buffer *eb)
{
+ struct extent_buffer_head *ebh;
unsigned long i;
struct page *page;
unsigned long num_pages;
+ int uptodate;
- set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
- num_pages = num_extent_pages(eb->start, eb->len);
- for (i = 0; i < num_pages; i++) {
- page = extent_buffer_page(eb, i);
- SetPageUptodate(page);
+ ebh = eb->ebh;
+
+ set_bit(EXTENT_BUFFER_UPTODATE, &eb->ebflags);
+ if (eb->len < PAGE_CACHE_SIZE) {
+ eb = &(eb_head(eb)->eb);
+ uptodate = 1;
+ do {
+ if (!test_bit(EXTENT_BUFFER_UPTODATE, &eb->ebflags)) {
+ uptodate = 0;
+ break;
+ }
+ } while ((eb = eb->eb_next) != NULL);
+
+ if (uptodate) {
+ page = extent_buffer_page(&ebh->eb, 0);
+ SetPageUptodate(page);
+ }
+ } else {
+ num_pages = num_extent_pages(eb->start, eb->len);
+ for (i = 0; i < num_pages; i++) {
+ page = extent_buffer_page(eb, i);
+ SetPageUptodate(page);
+ }
}
+
return 0;
}
int extent_buffer_uptodate(struct extent_buffer *eb)
{
- return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
+ return test_bit(EXTENT_BUFFER_UPTODATE, &eb->ebflags);
}
int read_extent_buffer_pages(struct extent_io_tree *tree,
@@ -5150,9 +5277,10 @@ void write_extent_buffer(struct extent_buffer *eb, const
void *srcv,
offset = (start_offset + start) & (PAGE_CACHE_SIZE - 1);
+ WARN_ON(!test_bit(EXTENT_BUFFER_UPTODATE, &eb->ebflags));
+
while (len > 0) {
page = extent_buffer_page(eb, i);
- WARN_ON(!PageUptodate(page));
cur = min(len, PAGE_CACHE_SIZE - offset);
kaddr = page_address(page);
@@ -5177,12 +5305,12 @@ void memset_extent_buffer(struct extent_buffer *eb,
char c,
WARN_ON(start > eb->len);
WARN_ON(start + len > eb->start + eb->len);
+ WARN_ON(!test_bit(EXTENT_BUFFER_UPTODATE, &eb->ebflags));
offset = (start_offset + start) & (PAGE_CACHE_SIZE - 1);
while (len > 0) {
page = extent_buffer_page(eb, i);
- WARN_ON(!PageUptodate(page));
cur = min(len, PAGE_CACHE_SIZE - offset);
kaddr = page_address(page);
@@ -5211,9 +5339,10 @@ void copy_extent_buffer(struct extent_buffer *dst,
struct extent_buffer *src,
offset = (start_offset + dst_offset) &
(PAGE_CACHE_SIZE - 1);
+ WARN_ON(!test_bit(EXTENT_BUFFER_UPTODATE, &dst->ebflags));
+
while (len > 0) {
page = extent_buffer_page(dst, i);
- WARN_ON(!PageUptodate(page));
cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
@@ -5350,6 +5479,7 @@ void memmove_extent_buffer(struct extent_buffer *dst,
unsigned long dst_offset,
int try_release_extent_buffer(struct page *page)
{
+ struct extent_buffer_head *ebh;
struct extent_buffer *eb;
/*
@@ -5365,14 +5495,15 @@ int try_release_extent_buffer(struct page *page)
eb = (struct extent_buffer *)page->private;
BUG_ON(!eb);
+ ebh = eb->ebh;
/*
* This is a little awful but should be ok, we need to make sure that
* the eb doesn't disappear out from under us while we're looking at
* this page.
*/
- spin_lock(&eb->refs_lock);
- if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
- spin_unlock(&eb->refs_lock);
+ spin_lock(&ebh->refs_lock);
+ if (atomic_read(&ebh->refs) != 1 || extent_buffer_under_io(eb)) {
+ spin_unlock(&ebh->refs_lock);
spin_unlock(&page->mapping->private_lock);
return 0;
}
@@ -5382,10 +5513,11 @@ int try_release_extent_buffer(struct page *page)
* If tree ref isn't set then we know the ref on this eb is a real ref,
* so just return, this page will likely be freed soon anyway.
*/
- if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
- spin_unlock(&eb->refs_lock);
+ if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &ebh->bflags)) {
+ spin_unlock(&ebh->refs_lock);
return 0;
}
- return release_extent_buffer(eb);
+ return release_extent_buffer(ebh);
}
+
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 58b27e5..fa0d576 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -123,19 +123,17 @@ struct extent_state {
#define INLINE_EXTENT_BUFFER_PAGES 16
#define MAX_INLINE_EXTENT_BUFFER_SIZE (INLINE_EXTENT_BUFFER_PAGES *
PAGE_CACHE_SIZE)
+
+/* Forward declaration */
+struct extent_buffer_head;
+
struct extent_buffer {
u64 start;
unsigned long len;
- unsigned long map_start;
- unsigned long map_len;
- unsigned long bflags;
- struct btrfs_fs_info *fs_info;
- spinlock_t refs_lock;
- atomic_t refs;
- atomic_t io_pages;
+ unsigned long ebflags;
+ struct extent_buffer_head *ebh;
+ struct extent_buffer *eb_next;
int read_mirror;
- struct rcu_head rcu_head;
- pid_t lock_owner;
/* count of read lock holders on the extent buffer */
atomic_t write_locks;
@@ -146,6 +144,8 @@ struct extent_buffer {
atomic_t spinning_writers;
int lock_nested;
+ pid_t lock_owner;
+
/* protects write locks */
rwlock_t lock;
@@ -159,7 +159,19 @@ struct extent_buffer {
*/
wait_queue_head_t read_lock_wq;
wait_queue_head_t lock_wq;
+};
+
+struct extent_buffer_head {
+ unsigned long bflags;
+ struct btrfs_fs_info *fs_info;
+ spinlock_t refs_lock;
+ atomic_t refs;
+ atomic_t io_bvecs;
+ struct rcu_head rcu_head;
+
struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
+
+ struct extent_buffer eb;
#ifdef CONFIG_BTRFS_DEBUG
struct list_head leak_list;
#endif
@@ -176,6 +188,14 @@ static inline int extent_compress_type(unsigned long
bio_flags)
return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
}
+/*
+ * return the extent_buffer_head that contains the extent buffer provided.
+ */
+static inline struct extent_buffer_head *eb_head(struct extent_buffer *eb)
+{
+ return eb->ebh;
+
+}
struct extent_map_tree;
typedef struct extent_map *(get_extent_t)(struct inode *inode,
@@ -287,15 +307,15 @@ static inline unsigned long num_extent_pages(u64 start,
u64 len)
(start >> PAGE_CACHE_SHIFT);
}
-static inline struct page *extent_buffer_page(struct extent_buffer *eb,
- unsigned long i)
+static inline struct page *extent_buffer_page(
+ struct extent_buffer *eb, unsigned long i)
{
- return eb->pages[i];
+ return eb_head(eb)->pages[i];
}
static inline void extent_buffer_get(struct extent_buffer *eb)
{
- atomic_inc(&eb->refs);
+ atomic_inc(&eb_head(eb)->refs);
}
int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 07629e9..1ec359b 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5936,7 +5936,7 @@ int btrfs_read_sys_array(struct btrfs_root *root)
* to silence the warning eg. on PowerPC 64.
*/
if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
- SetPageUptodate(sb->pages[0]);
+ SetPageUptodate(eb_head(sb)->pages[0]);
write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
array_size = btrfs_super_sys_array_size(super_copy);
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 3176cdc..5b79ac2 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -695,7 +695,7 @@ TRACE_EVENT(btrfs_cow_block,
TP_fast_assign(
__entry->root_objectid = root->root_key.objectid;
__entry->buf_start = buf->start;
- __entry->refs = atomic_read(&buf->refs);
+ __entry->refs = atomic_read(&eb_head(buf)->refs);
__entry->cow_start = cow->start;
__entry->buf_level = btrfs_header_level(buf);
__entry->cow_level = btrfs_header_level(cow);
--
1.8.3.1
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
