[PATCH 1/3] btrfs: use list_for_each_entry* in check-integrity.c

[PATCH 1/3] btrfs: use list_for_each_entry* in check-integrity.c

[Geliang Tang]

Use list_for_each_entry*() instead of list_for_each*() to simplify
the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
 fs/btrfs/check-integrity.c | 105 +++++++++++----------------------------------
 1 file changed, 26 insertions(+), 79 deletions(-)

diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 0340c57..861d472 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -531,13 +531,9 @@ static struct btrfsic_block *btrfsic_block_hashtable_lookup(
 	    (((unsigned int)(dev_bytenr >> 16)) ^
 	     ((unsigned int)((uintptr_t)bdev))) &
 	     (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1);
-	struct list_head *elem;
-
-	list_for_each(elem, h->table + hashval) {
-		struct btrfsic_block *const b =
-		    list_entry(elem, struct btrfsic_block,
-			       collision_resolving_node);
+	struct btrfsic_block *b;
 
+	list_for_each_entry(b, h->table + hashval, collision_resolving_node) {
 		if (b->dev_state->bdev == bdev && b->dev_bytenr == dev_bytenr)
 			return b;
 	}
@@ -588,13 +584,9 @@ static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup(
 	     ((unsigned int)((uintptr_t)bdev_ref_to)) ^
 	     ((unsigned int)((uintptr_t)bdev_ref_from))) &
 	     (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1);
-	struct list_head *elem;
-
-	list_for_each(elem, h->table + hashval) {
-		struct btrfsic_block_link *const l =
-		    list_entry(elem, struct btrfsic_block_link,
-			       collision_resolving_node);
+	struct btrfsic_block_link *l;
 
+	list_for_each_entry(l, h->table + hashval, collision_resolving_node) {
 		BUG_ON(NULL == l->block_ref_to);
 		BUG_ON(NULL == l->block_ref_from);
 		if (l->block_ref_to->dev_state->bdev == bdev_ref_to &&
@@ -639,13 +631,9 @@ static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(
 	const unsigned int hashval =
 	    (((unsigned int)((uintptr_t)bdev)) &
 	     (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1));
-	struct list_head *elem;
-
-	list_for_each(elem, h->table + hashval) {
-		struct btrfsic_dev_state *const ds =
-		    list_entry(elem, struct btrfsic_dev_state,
-			       collision_resolving_node);
+	struct btrfsic_dev_state *ds;
 
+	list_for_each_entry(ds, h->table + hashval, collision_resolving_node) {
 		if (ds->bdev == bdev)
 			return ds;
 	}
@@ -1720,29 +1708,20 @@ static int btrfsic_read_block(struct btrfsic_state *state,
 
 static void btrfsic_dump_database(struct btrfsic_state *state)
 {
-	struct list_head *elem_all;
+	const struct btrfsic_block *b_all;
 
 	BUG_ON(NULL == state);
 
 	printk(KERN_INFO "all_blocks_list:\n");
-	list_for_each(elem_all, &state->all_blocks_list) {
-		const struct btrfsic_block *const b_all =
-		    list_entry(elem_all, struct btrfsic_block,
-			       all_blocks_node);
-		struct list_head *elem_ref_to;
-		struct list_head *elem_ref_from;
+	list_for_each_entry(b_all, &state->all_blocks_list, all_blocks_node) {
+		const struct btrfsic_block_link *l;
 
 		printk(KERN_INFO "%c-block @%llu (%s/%llu/%d)\n",
 		       btrfsic_get_block_type(state, b_all),
 		       b_all->logical_bytenr, b_all->dev_state->name,
 		       b_all->dev_bytenr, b_all->mirror_num);
 
-		list_for_each(elem_ref_to, &b_all->ref_to_list) {
-			const struct btrfsic_block_link *const l =
-			    list_entry(elem_ref_to,
-				       struct btrfsic_block_link,
-				       node_ref_to);
-
+		list_for_each_entry(l, &b_all->ref_to_list, node_ref_to) {
 			printk(KERN_INFO " %c @%llu (%s/%llu/%d)"
 			       " refers %u* to"
 			       " %c @%llu (%s/%llu/%d)\n",
@@ -1757,12 +1736,7 @@ static void btrfsic_dump_database(struct btrfsic_state *state)
 			       l->block_ref_to->mirror_num);
 		}
 
-		list_for_each(elem_ref_from, &b_all->ref_from_list) {
-			const struct btrfsic_block_link *const l =
-			    list_entry(elem_ref_from,
-				       struct btrfsic_block_link,
-				       node_ref_from);
-
+		list_for_each_entry(l, &b_all->ref_from_list, node_ref_from) {
 			printk(KERN_INFO " %c @%llu (%s/%llu/%d)"
 			       " is ref %u* from"
 			       " %c @%llu (%s/%llu/%d)\n",
@@ -1845,8 +1819,7 @@ again:
 					       &state->block_hashtable);
 	if (NULL != block) {
 		u64 bytenr = 0;
-		struct list_head *elem_ref_to;
-		struct list_head *tmp_ref_to;
+		struct btrfsic_block_link *l, *tmp;
 
 		if (block->is_superblock) {
 			bytenr = btrfs_super_bytenr((struct btrfs_super_block *)
@@ -1967,13 +1940,8 @@ again:
 		 * because it still carries valueable information
 		 * like whether it was ever written and IO completed.
 		 */
-		list_for_each_safe(elem_ref_to, tmp_ref_to,
-				   &block->ref_to_list) {
-			struct btrfsic_block_link *const l =
-			    list_entry(elem_ref_to,
-				       struct btrfsic_block_link,
-				       node_ref_to);
-
+		list_for_each_entry_safe(l, tmp, &block->ref_to_list,
+					 node_ref_to) {
 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
 				btrfsic_print_rem_link(state, l);
 			l->ref_cnt--;
@@ -2436,7 +2404,7 @@ static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
 					struct btrfsic_block *const block,
 					int recursion_level)
 {
-	struct list_head *elem_ref_to;
+	const struct btrfsic_block_link *l;
 	int ret = 0;
 
 	if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
@@ -2464,11 +2432,7 @@ static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
 	 * This algorithm is recursive because the amount of used stack
 	 * space is very small and the max recursion depth is limited.
 	 */
-	list_for_each(elem_ref_to, &block->ref_to_list) {
-		const struct btrfsic_block_link *const l =
-		    list_entry(elem_ref_to, struct btrfsic_block_link,
-			       node_ref_to);
-
+	list_for_each_entry(l, &block->ref_to_list, node_ref_to) {
 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
 			printk(KERN_INFO
 			       "rl=%d, %c @%llu (%s/%llu/%d)"
@@ -2561,7 +2525,7 @@ static int btrfsic_is_block_ref_by_superblock(
 		const struct btrfsic_block *block,
 		int recursion_level)
 {
-	struct list_head *elem_ref_from;
+	const struct btrfsic_block_link *l;
 
 	if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
 		/* refer to comment at "abort cyclic linkage (case 1)" */
@@ -2576,11 +2540,7 @@ static int btrfsic_is_block_ref_by_superblock(
 	 * This algorithm is recursive because the amount of used stack space
 	 * is very small and the max recursion depth is limited.
 	 */
-	list_for_each(elem_ref_from, &block->ref_from_list) {
-		const struct btrfsic_block_link *const l =
-		    list_entry(elem_ref_from, struct btrfsic_block_link,
-			       node_ref_from);
-
+	list_for_each_entry(l, &block->ref_from_list, node_ref_from) {
 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
 			printk(KERN_INFO
 			       "rl=%d, %c @%llu (%s/%llu/%d)"
@@ -2669,7 +2629,7 @@ static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
 				  const struct btrfsic_block *block,
 				  int indent_level)
 {
-	struct list_head *elem_ref_to;
+	const struct btrfsic_block_link *l;
 	int indent_add;
 	static char buf[80];
 	int cursor_position;
@@ -2704,11 +2664,7 @@ static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
 	}
 
 	cursor_position = indent_level;
-	list_for_each(elem_ref_to, &block->ref_to_list) {
-		const struct btrfsic_block_link *const l =
-		    list_entry(elem_ref_to, struct btrfsic_block_link,
-			       node_ref_to);
-
+	list_for_each_entry(l, &block->ref_to_list, node_ref_to) {
 		while (cursor_position < indent_level) {
 			printk(" ");
 			cursor_position++;
@@ -3165,8 +3121,7 @@ int btrfsic_mount(struct btrfs_root *root,
 void btrfsic_unmount(struct btrfs_root *root,
 		     struct btrfs_fs_devices *fs_devices)
 {
-	struct list_head *elem_all;
-	struct list_head *tmp_all;
+	struct btrfsic_block *b_all, *tmp_all;
 	struct btrfsic_state *state;
 	struct list_head *dev_head = &fs_devices->devices;
 	struct btrfs_device *device;
@@ -3206,20 +3161,12 @@ void btrfsic_unmount(struct btrfs_root *root,
 	 * just free all memory that was allocated dynamically.
 	 * Free the blocks and the block_links.
 	 */
-	list_for_each_safe(elem_all, tmp_all, &state->all_blocks_list) {
-		struct btrfsic_block *const b_all =
-		    list_entry(elem_all, struct btrfsic_block,
-			       all_blocks_node);
-		struct list_head *elem_ref_to;
-		struct list_head *tmp_ref_to;
-
-		list_for_each_safe(elem_ref_to, tmp_ref_to,
-				   &b_all->ref_to_list) {
-			struct btrfsic_block_link *const l =
-			    list_entry(elem_ref_to,
-				       struct btrfsic_block_link,
-				       node_ref_to);
+	list_for_each_entry_safe(b_all, tmp_all, &state->all_blocks_list,
+				 all_blocks_node) {
+		struct btrfsic_block_link *l, *tmp;
 
+		list_for_each_entry_safe(l, tmp, &b_all->ref_to_list,
+					 node_ref_to) {
 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
 				btrfsic_print_rem_link(state, l);
 
-- 
2.5.0

[PATCH 2/3] btrfs: use list_for_each_entry_safe in free-space-cache.c

[Geliang Tang]

Use list_for_each_entry_safe() instead of list_for_each_safe() to
simplify the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
 fs/btrfs/free-space-cache.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 85a1f86..a368bc8 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -1086,14 +1086,11 @@ write_pinned_extent_entries(struct btrfs_root *root,
 static noinline_for_stack int
 write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
 {
-	struct list_head *pos, *n;
+	struct btrfs_free_space *entry, *next;
 	int ret;
 
 	/* Write out the bitmaps */
-	list_for_each_safe(pos, n, bitmap_list) {
-		struct btrfs_free_space *entry =
-			list_entry(pos, struct btrfs_free_space, list);
-
+	list_for_each_entry_safe(entry, next, bitmap_list, list) {
 		ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
 		if (ret)
 			return -ENOSPC;
@@ -1119,13 +1116,10 @@ static int flush_dirty_cache(struct inode *inode)
 static void noinline_for_stack
 cleanup_bitmap_list(struct list_head *bitmap_list)
 {
-	struct list_head *pos, *n;
+	struct btrfs_free_space *entry, *next;
 
-	list_for_each_safe(pos, n, bitmap_list) {
-		struct btrfs_free_space *entry =
-			list_entry(pos, struct btrfs_free_space, list);
+	list_for_each_entry_safe(entry, next, bitmap_list, list)
 		list_del_init(&entry->list);
-	}
 }
 
 static void noinline_for_stack
-- 
2.5.0

[PATCH 3/3] btrfs: use list_for_each_entry* in backref.c

[Geliang Tang]

Use list_for_each_entry*() to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
 fs/btrfs/backref.c | 24 +++++++-----------------
 1 file changed, 7 insertions(+), 17 deletions(-)

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index d453d62..fa6f346 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -520,13 +520,10 @@ static inline int ref_for_same_block(struct __prelim_ref *ref1,
 static int __add_missing_keys(struct btrfs_fs_info *fs_info,
 			      struct list_head *head)
 {
-	struct list_head *pos;
+	struct __prelim_ref *ref;
 	struct extent_buffer *eb;
 
-	list_for_each(pos, head) {
-		struct __prelim_ref *ref;
-		ref = list_entry(pos, struct __prelim_ref, list);
-
+	list_for_each_entry(ref, head, list) {
 		if (ref->parent)
 			continue;
 		if (ref->key_for_search.type)
@@ -563,23 +560,16 @@ static int __add_missing_keys(struct btrfs_fs_info *fs_info,
  */
 static void __merge_refs(struct list_head *head, int mode)
 {
-	struct list_head *pos1;
+	struct __prelim_ref *ref1;
 
-	list_for_each(pos1, head) {
-		struct list_head *n2;
-		struct list_head *pos2;
-		struct __prelim_ref *ref1;
+	list_for_each_entry(ref1, head, list) {
+		struct __prelim_ref *ref2, *tmp;
 
-		ref1 = list_entry(pos1, struct __prelim_ref, list);
-
-		for (pos2 = pos1->next, n2 = pos2->next; pos2 != head;
-		     pos2 = n2, n2 = pos2->next) {
-			struct __prelim_ref *ref2;
+		ref2 = list_next_entry(ref1, list);
+		list_for_each_entry_safe_from(ref2, tmp, head, list) {
 			struct __prelim_ref *xchg;
 			struct extent_inode_elem *eie;
 
-			ref2 = list_entry(pos2, struct __prelim_ref, list);
-
 			if (!ref_for_same_block(ref1, ref2))
 				continue;
 			if (mode == 1) {
-- 
2.5.0

[PATCH 3/3 v2] btrfs: use list_for_each_entry* in backref.c

[Geliang Tang]

Use list_for_each_entry*() to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
Changes in v2:
 - Use list_for_each_entry_safe_continue() in __merge_refs().
---
 fs/btrfs/backref.c | 23 ++++++-----------------
 1 file changed, 6 insertions(+), 17 deletions(-)

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index d453d62..08405a3 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -520,13 +520,10 @@ static inline int ref_for_same_block(struct __prelim_ref *ref1,
 static int __add_missing_keys(struct btrfs_fs_info *fs_info,
 			      struct list_head *head)
 {
-	struct list_head *pos;
+	struct __prelim_ref *ref;
 	struct extent_buffer *eb;
 
-	list_for_each(pos, head) {
-		struct __prelim_ref *ref;
-		ref = list_entry(pos, struct __prelim_ref, list);
-
+	list_for_each_entry(ref, head, list) {
 		if (ref->parent)
 			continue;
 		if (ref->key_for_search.type)
@@ -563,23 +560,15 @@ static int __add_missing_keys(struct btrfs_fs_info *fs_info,
  */
 static void __merge_refs(struct list_head *head, int mode)
 {
-	struct list_head *pos1;
+	struct __prelim_ref *ref1;
 
-	list_for_each(pos1, head) {
-		struct list_head *n2;
-		struct list_head *pos2;
-		struct __prelim_ref *ref1;
+	list_for_each_entry(ref1, head, list) {
+		struct __prelim_ref *ref2 = ref1, *tmp;
 
-		ref1 = list_entry(pos1, struct __prelim_ref, list);
-
-		for (pos2 = pos1->next, n2 = pos2->next; pos2 != head;
-		     pos2 = n2, n2 = pos2->next) {
-			struct __prelim_ref *ref2;
+		list_for_each_entry_safe_continue(ref2, tmp, head, list) {
 			struct __prelim_ref *xchg;
 			struct extent_inode_elem *eie;
 
-			ref2 = list_entry(pos2, struct __prelim_ref, list);
-
 			if (!ref_for_same_block(ref1, ref2))
 				continue;
 			if (mode == 1) {
-- 
2.5.0

Re: [PATCH 1/3] btrfs: use list_for_each_entry* in check-integrity.c

[David Sterba]

On Fri, Dec 18, 2015 at 10:16:59PM +0800, Geliang Tang wrote:
> Use list_for_each_entry*() instead of list_for_each*() to simplify
> the code.
> 
> Signed-off-by: Geliang Tang <geliangtang@163.com>

Reviewed-by: David Sterba <dsterba@suse.com>

Re: [PATCH 2/3] btrfs: use list_for_each_entry_safe in free-space-cache.c

[David Sterba]

On Fri, Dec 18, 2015 at 10:17:00PM +0800, Geliang Tang wrote:
> Use list_for_each_entry_safe() instead of list_for_each_safe() to
> simplify the code.
> 
> Signed-off-by: Geliang Tang <geliangtang@163.com>

Reviewed-by: David Sterba <dsterba@suse.com>

Re: [PATCH 3/3 v2] btrfs: use list_for_each_entry* in backref.c

[David Sterba]

On Mon, Dec 21, 2015 at 11:50:23PM +0800, Geliang Tang wrote:
> Use list_for_each_entry*() to simplify the code.
> 
> Signed-off-by: Geliang Tang <geliangtang@163.com>

Reviewed-by: David Sterba <dsterba@suse.com>