[PATCH 0/2] btrfs: drop no longer needed atomic allocation for tree mod log operations

[PATCH 0/2] btrfs: drop no longer needed atomic allocation for tree mod log operations

[fdmanana]

From: Filipe Manana <fdmanana@suse.com>

We are still doing an atomic memory allocation for tree mod log operations
which is not needed anymore after we switch extent buffer locks to rw
semaphores. This replaces that atomic allocation with a GFP_NOFS one, and
then removes redundant gfp_t argument for btrfs_tree_mod_log_insert_key().

Filipe Manana (2):
  btrfs: switch GFP_ATOMIC to GFP_NOFS when fixing up low keys
  btrfs: remove gfp_t flag from btrfs_tree_mod_log_insert_key()

 fs/btrfs/ctree.c        | 16 ++++++++--------
 fs/btrfs/tree-mod-log.c |  4 ++--
 fs/btrfs/tree-mod-log.h |  2 +-
 3 files changed, 11 insertions(+), 11 deletions(-)

-- 
2.35.1

[PATCH 1/2] btrfs: switch GFP_ATOMIC to GFP_NOFS when fixing up low keys

[fdmanana]

From: Filipe Manana <fdmanana@suse.com>

When fixing up the first key of each node above the current level, at
fixup_low_keys(), we are doing a GFP_ATOMIC allocation for inserting an
operation record for the tree mod log. However we can do just fine with
GFP_NOFS nowadays. The need for GFP_ATOMIC was for the old days when we
had custom locks with spinning behaviour for extent buffers and we were
in spinning mode while at fixup_low_keys(). Now we use rw semaphores for
extent buffer locks, so we can safely use GFP_NOFS.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/ctree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index b39b339fbf96..5d4add61f0a0 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2400,7 +2400,7 @@ static void fixup_low_keys(struct btrfs_path *path,
 			break;
 		t = path->nodes[i];
 		ret = btrfs_tree_mod_log_insert_key(t, tslot,
-				BTRFS_MOD_LOG_KEY_REPLACE, GFP_ATOMIC);
+				BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
 		BUG_ON(ret < 0);
 		btrfs_set_node_key(t, key, tslot);
 		btrfs_mark_buffer_dirty(path->nodes[i]);
-- 
2.35.1

[PATCH 2/2] btrfs: remove gfp_t flag from btrfs_tree_mod_log_insert_key()

[fdmanana]

From: Filipe Manana <fdmanana@suse.com>

All callers of btrfs_tree_mod_log_insert_key() are now passing a GFP_NOFS
gfp_t flag to it, so remove the flag and use it directly within the body
of btrfs_tree_mod_log_insert_key().

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/ctree.c        | 16 ++++++++--------
 fs/btrfs/tree-mod-log.c |  4 ++--
 fs/btrfs/tree-mod-log.h |  2 +-
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 5d4add61f0a0..861ac12815b7 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -471,7 +471,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
 	} else {
 		WARN_ON(trans->transid != btrfs_header_generation(parent));
 		btrfs_tree_mod_log_insert_key(parent, parent_slot,
-					      BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
+					      BTRFS_MOD_LOG_KEY_REPLACE);
 		btrfs_set_node_blockptr(parent, parent_slot,
 					cow->start);
 		btrfs_set_node_ptr_generation(parent, parent_slot,
@@ -1000,7 +1000,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 			struct btrfs_disk_key right_key;
 			btrfs_node_key(right, &right_key, 0);
 			ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1,
-					BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
+					BTRFS_MOD_LOG_KEY_REPLACE);
 			BUG_ON(ret < 0);
 			btrfs_set_node_key(parent, &right_key, pslot + 1);
 			btrfs_mark_buffer_dirty(parent);
@@ -1046,7 +1046,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		struct btrfs_disk_key mid_key;
 		btrfs_node_key(mid, &mid_key, 0);
 		ret = btrfs_tree_mod_log_insert_key(parent, pslot,
-				BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
+						    BTRFS_MOD_LOG_KEY_REPLACE);
 		BUG_ON(ret < 0);
 		btrfs_set_node_key(parent, &mid_key, pslot);
 		btrfs_mark_buffer_dirty(parent);
@@ -1148,7 +1148,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
 			orig_slot += left_nr;
 			btrfs_node_key(mid, &disk_key, 0);
 			ret = btrfs_tree_mod_log_insert_key(parent, pslot,
-					BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
+					BTRFS_MOD_LOG_KEY_REPLACE);
 			BUG_ON(ret < 0);
 			btrfs_set_node_key(parent, &disk_key, pslot);
 			btrfs_mark_buffer_dirty(parent);
@@ -1202,7 +1202,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
 
 			btrfs_node_key(right, &disk_key, 0);
 			ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1,
-					BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
+					BTRFS_MOD_LOG_KEY_REPLACE);
 			BUG_ON(ret < 0);
 			btrfs_set_node_key(parent, &disk_key, pslot + 1);
 			btrfs_mark_buffer_dirty(parent);
@@ -2400,7 +2400,7 @@ static void fixup_low_keys(struct btrfs_path *path,
 			break;
 		t = path->nodes[i];
 		ret = btrfs_tree_mod_log_insert_key(t, tslot,
-				BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
+						    BTRFS_MOD_LOG_KEY_REPLACE);
 		BUG_ON(ret < 0);
 		btrfs_set_node_key(t, key, tslot);
 		btrfs_mark_buffer_dirty(path->nodes[i]);
@@ -2761,7 +2761,7 @@ static void insert_ptr(struct btrfs_trans_handle *trans,
 	}
 	if (level) {
 		ret = btrfs_tree_mod_log_insert_key(lower, slot,
-					    BTRFS_MOD_LOG_KEY_ADD, GFP_NOFS);
+						    BTRFS_MOD_LOG_KEY_ADD);
 		BUG_ON(ret < 0);
 	}
 	btrfs_set_node_key(lower, key, slot);
@@ -4201,7 +4201,7 @@ static void del_ptr(struct btrfs_root *root, struct btrfs_path *path,
 			      (nritems - slot - 1));
 	} else if (level) {
 		ret = btrfs_tree_mod_log_insert_key(parent, slot,
-				BTRFS_MOD_LOG_KEY_REMOVE, GFP_NOFS);
+						    BTRFS_MOD_LOG_KEY_REMOVE);
 		BUG_ON(ret < 0);
 	}
 
diff --git a/fs/btrfs/tree-mod-log.c b/fs/btrfs/tree-mod-log.c
index 8a3a14686d3e..6606534fc36a 100644
--- a/fs/btrfs/tree-mod-log.c
+++ b/fs/btrfs/tree-mod-log.c
@@ -220,7 +220,7 @@ static struct tree_mod_elem *alloc_tree_mod_elem(struct extent_buffer *eb,
 }
 
 int btrfs_tree_mod_log_insert_key(struct extent_buffer *eb, int slot,
-				  enum btrfs_mod_log_op op, gfp_t flags)
+				  enum btrfs_mod_log_op op)
 {
 	struct tree_mod_elem *tm;
 	int ret;
@@ -228,7 +228,7 @@ int btrfs_tree_mod_log_insert_key(struct extent_buffer *eb, int slot,
 	if (!tree_mod_need_log(eb->fs_info, eb))
 		return 0;
 
-	tm = alloc_tree_mod_elem(eb, slot, op, flags);
+	tm = alloc_tree_mod_elem(eb, slot, op, GFP_NOFS);
 	if (!tm)
 		return -ENOMEM;
 
diff --git a/fs/btrfs/tree-mod-log.h b/fs/btrfs/tree-mod-log.h
index 12605d19621b..8cffe0bc2a39 100644
--- a/fs/btrfs/tree-mod-log.h
+++ b/fs/btrfs/tree-mod-log.h
@@ -32,7 +32,7 @@ int btrfs_tree_mod_log_insert_root(struct extent_buffer *old_root,
 				   struct extent_buffer *new_root,
 				   bool log_removal);
 int btrfs_tree_mod_log_insert_key(struct extent_buffer *eb, int slot,
-				  enum btrfs_mod_log_op op, gfp_t flags);
+				  enum btrfs_mod_log_op op);
 int btrfs_tree_mod_log_free_eb(struct extent_buffer *eb);
 struct extent_buffer *btrfs_tree_mod_log_rewind(struct btrfs_fs_info *fs_info,
 						struct btrfs_path *path,
-- 
2.35.1

Re: [PATCH 2/2] btrfs: remove gfp_t flag from btrfs_tree_mod_log_insert_key()

[David Sterba]

On Thu, Oct 13, 2022 at 11:36:26AM +0100, fdmanana@kernel.org wrote:
>index 8a3a14686d3e..6606534fc36a 100644
> --- a/fs/btrfs/tree-mod-log.c
> +++ b/fs/btrfs/tree-mod-log.c
> @@ -220,7 +220,7 @@ static struct tree_mod_elem *alloc_tree_mod_elem(struct extent_buffer *eb,
>  }
>  
>  int btrfs_tree_mod_log_insert_key(struct extent_buffer *eb, int slot,
> -				  enum btrfs_mod_log_op op, gfp_t flags)
> +				  enum btrfs_mod_log_op op)
>  {
>  	struct tree_mod_elem *tm;
>  	int ret;
> @@ -228,7 +228,7 @@ int btrfs_tree_mod_log_insert_key(struct extent_buffer *eb, int slot,
>  	if (!tree_mod_need_log(eb->fs_info, eb))
>  		return 0;
>  
> -	tm = alloc_tree_mod_elem(eb, slot, op, flags);
> +	tm = alloc_tree_mod_elem(eb, slot, op, GFP_NOFS);

And after that alloc_tree_mod_elem is also called only with GFP_NOFS.

>  	if (!tm)
>  		return -ENOMEM;
>  

Re: [PATCH 0/2] btrfs: drop no longer needed atomic allocation for tree mod log operations

[David Sterba]

On Thu, Oct 13, 2022 at 11:36:24AM +0100, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> We are still doing an atomic memory allocation for tree mod log operations
> which is not needed anymore after we switch extent buffer locks to rw
> semaphores. This replaces that atomic allocation with a GFP_NOFS one, and
> then removes redundant gfp_t argument for btrfs_tree_mod_log_insert_key().
> 
> Filipe Manana (2):
>   btrfs: switch GFP_ATOMIC to GFP_NOFS when fixing up low keys
>   btrfs: remove gfp_t flag from btrfs_tree_mod_log_insert_key()

Added to misc-next, thanks.

[PATCH v2 0/2] btrfs: drop no longer needed atomic allocation for tree mod log operations

[fdmanana]

From: Filipe Manana <fdmanana@suse.com>

We are still doing an atomic memory allocation for tree mod log operations
which is not needed anymore after we switch extent buffer locks to rw
semaphores. This replaces that atomic allocation with a GFP_NOFS one, and
then removes redundant gfp_t argument for btrfs_tree_mod_log_insert_key().

V2: Updated patch 2/2 to also remove the allocation flag from
    alloc_tree_mod_elem().

Filipe Manana (2):
  btrfs: switch GFP_ATOMIC to GFP_NOFS when fixing up low keys
  btrfs: remove gfp_t flag from btrfs_tree_mod_log_insert_key()

 fs/btrfs/ctree.c        | 16 ++++++++--------
 fs/btrfs/tree-mod-log.c | 19 +++++++++----------
 fs/btrfs/tree-mod-log.h |  2 +-
 3 files changed, 18 insertions(+), 19 deletions(-)

-- 
2.35.1

[PATCH v2 1/2] btrfs: switch GFP_ATOMIC to GFP_NOFS when fixing up low keys

[fdmanana]

From: Filipe Manana <fdmanana@suse.com>

When fixing up the first key of each node above the current level, at
fixup_low_keys(), we are doing a GFP_ATOMIC allocation for inserting an
operation record for the tree mod log. However we can do just fine with
GFP_NOFS nowadays. The need for GFP_ATOMIC was for the old days when we
had custom locks with spinning behaviour for extent buffers and we were
in spinning mode while at fixup_low_keys(). Now we use rw semaphores for
extent buffer locks, so we can safely use GFP_NOFS.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/ctree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index b39b339fbf96..5d4add61f0a0 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2400,7 +2400,7 @@ static void fixup_low_keys(struct btrfs_path *path,
 			break;
 		t = path->nodes[i];
 		ret = btrfs_tree_mod_log_insert_key(t, tslot,
-				BTRFS_MOD_LOG_KEY_REPLACE, GFP_ATOMIC);
+				BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
 		BUG_ON(ret < 0);
 		btrfs_set_node_key(t, key, tslot);
 		btrfs_mark_buffer_dirty(path->nodes[i]);
-- 
2.35.1

[PATCH v2 2/2] btrfs: remove gfp_t flag from btrfs_tree_mod_log_insert_key()

[fdmanana]

From: Filipe Manana <fdmanana@suse.com>

All callers of btrfs_tree_mod_log_insert_key() are now passing a GFP_NOFS
flag to it, so remove the flag from it and from alloc_tree_mod_elem() and
use it directly within alloc_tree_mod_elem().

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/ctree.c        | 16 ++++++++--------
 fs/btrfs/tree-mod-log.c | 19 +++++++++----------
 fs/btrfs/tree-mod-log.h |  2 +-
 3 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 5d4add61f0a0..861ac12815b7 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -471,7 +471,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
 	} else {
 		WARN_ON(trans->transid != btrfs_header_generation(parent));
 		btrfs_tree_mod_log_insert_key(parent, parent_slot,
-					      BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
+					      BTRFS_MOD_LOG_KEY_REPLACE);
 		btrfs_set_node_blockptr(parent, parent_slot,
 					cow->start);
 		btrfs_set_node_ptr_generation(parent, parent_slot,
@@ -1000,7 +1000,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 			struct btrfs_disk_key right_key;
 			btrfs_node_key(right, &right_key, 0);
 			ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1,
-					BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
+					BTRFS_MOD_LOG_KEY_REPLACE);
 			BUG_ON(ret < 0);
 			btrfs_set_node_key(parent, &right_key, pslot + 1);
 			btrfs_mark_buffer_dirty(parent);
@@ -1046,7 +1046,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		struct btrfs_disk_key mid_key;
 		btrfs_node_key(mid, &mid_key, 0);
 		ret = btrfs_tree_mod_log_insert_key(parent, pslot,
-				BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
+						    BTRFS_MOD_LOG_KEY_REPLACE);
 		BUG_ON(ret < 0);
 		btrfs_set_node_key(parent, &mid_key, pslot);
 		btrfs_mark_buffer_dirty(parent);
@@ -1148,7 +1148,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
 			orig_slot += left_nr;
 			btrfs_node_key(mid, &disk_key, 0);
 			ret = btrfs_tree_mod_log_insert_key(parent, pslot,
-					BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
+					BTRFS_MOD_LOG_KEY_REPLACE);
 			BUG_ON(ret < 0);
 			btrfs_set_node_key(parent, &disk_key, pslot);
 			btrfs_mark_buffer_dirty(parent);
@@ -1202,7 +1202,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
 
 			btrfs_node_key(right, &disk_key, 0);
 			ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1,
-					BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
+					BTRFS_MOD_LOG_KEY_REPLACE);
 			BUG_ON(ret < 0);
 			btrfs_set_node_key(parent, &disk_key, pslot + 1);
 			btrfs_mark_buffer_dirty(parent);
@@ -2400,7 +2400,7 @@ static void fixup_low_keys(struct btrfs_path *path,
 			break;
 		t = path->nodes[i];
 		ret = btrfs_tree_mod_log_insert_key(t, tslot,
-				BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS);
+						    BTRFS_MOD_LOG_KEY_REPLACE);
 		BUG_ON(ret < 0);
 		btrfs_set_node_key(t, key, tslot);
 		btrfs_mark_buffer_dirty(path->nodes[i]);
@@ -2761,7 +2761,7 @@ static void insert_ptr(struct btrfs_trans_handle *trans,
 	}
 	if (level) {
 		ret = btrfs_tree_mod_log_insert_key(lower, slot,
-					    BTRFS_MOD_LOG_KEY_ADD, GFP_NOFS);
+						    BTRFS_MOD_LOG_KEY_ADD);
 		BUG_ON(ret < 0);
 	}
 	btrfs_set_node_key(lower, key, slot);
@@ -4201,7 +4201,7 @@ static void del_ptr(struct btrfs_root *root, struct btrfs_path *path,
 			      (nritems - slot - 1));
 	} else if (level) {
 		ret = btrfs_tree_mod_log_insert_key(parent, slot,
-				BTRFS_MOD_LOG_KEY_REMOVE, GFP_NOFS);
+						    BTRFS_MOD_LOG_KEY_REMOVE);
 		BUG_ON(ret < 0);
 	}
 
diff --git a/fs/btrfs/tree-mod-log.c b/fs/btrfs/tree-mod-log.c
index 8a3a14686d3e..18b4699bcb11 100644
--- a/fs/btrfs/tree-mod-log.c
+++ b/fs/btrfs/tree-mod-log.c
@@ -197,12 +197,11 @@ static inline bool tree_mod_need_log(const struct btrfs_fs_info *fs_info,
 
 static struct tree_mod_elem *alloc_tree_mod_elem(struct extent_buffer *eb,
 						 int slot,
-						 enum btrfs_mod_log_op op,
-						 gfp_t flags)
+						 enum btrfs_mod_log_op op)
 {
 	struct tree_mod_elem *tm;
 
-	tm = kzalloc(sizeof(*tm), flags);
+	tm = kzalloc(sizeof(*tm), GFP_NOFS);
 	if (!tm)
 		return NULL;
 
@@ -220,7 +219,7 @@ static struct tree_mod_elem *alloc_tree_mod_elem(struct extent_buffer *eb,
 }
 
 int btrfs_tree_mod_log_insert_key(struct extent_buffer *eb, int slot,
-				  enum btrfs_mod_log_op op, gfp_t flags)
+				  enum btrfs_mod_log_op op)
 {
 	struct tree_mod_elem *tm;
 	int ret;
@@ -228,7 +227,7 @@ int btrfs_tree_mod_log_insert_key(struct extent_buffer *eb, int slot,
 	if (!tree_mod_need_log(eb->fs_info, eb))
 		return 0;
 
-	tm = alloc_tree_mod_elem(eb, slot, op, flags);
+	tm = alloc_tree_mod_elem(eb, slot, op);
 	if (!tm)
 		return -ENOMEM;
 
@@ -276,7 +275,7 @@ int btrfs_tree_mod_log_insert_move(struct extent_buffer *eb,
 
 	for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) {
 		tm_list[i] = alloc_tree_mod_elem(eb, i + dst_slot,
-				BTRFS_MOD_LOG_KEY_REMOVE_WHILE_MOVING, GFP_NOFS);
+				BTRFS_MOD_LOG_KEY_REMOVE_WHILE_MOVING);
 		if (!tm_list[i]) {
 			ret = -ENOMEM;
 			goto free_tms;
@@ -364,7 +363,7 @@ int btrfs_tree_mod_log_insert_root(struct extent_buffer *old_root,
 		}
 		for (i = 0; i < nritems; i++) {
 			tm_list[i] = alloc_tree_mod_elem(old_root, i,
-			    BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING, GFP_NOFS);
+			    BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING);
 			if (!tm_list[i]) {
 				ret = -ENOMEM;
 				goto free_tms;
@@ -502,14 +501,14 @@ int btrfs_tree_mod_log_eb_copy(struct extent_buffer *dst,
 	tm_list_rem = tm_list + nr_items;
 	for (i = 0; i < nr_items; i++) {
 		tm_list_rem[i] = alloc_tree_mod_elem(src, i + src_offset,
-		    BTRFS_MOD_LOG_KEY_REMOVE, GFP_NOFS);
+						     BTRFS_MOD_LOG_KEY_REMOVE);
 		if (!tm_list_rem[i]) {
 			ret = -ENOMEM;
 			goto free_tms;
 		}
 
 		tm_list_add[i] = alloc_tree_mod_elem(dst, i + dst_offset,
-						BTRFS_MOD_LOG_KEY_ADD, GFP_NOFS);
+						     BTRFS_MOD_LOG_KEY_ADD);
 		if (!tm_list_add[i]) {
 			ret = -ENOMEM;
 			goto free_tms;
@@ -564,7 +563,7 @@ int btrfs_tree_mod_log_free_eb(struct extent_buffer *eb)
 
 	for (i = 0; i < nritems; i++) {
 		tm_list[i] = alloc_tree_mod_elem(eb, i,
-		    BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING, GFP_NOFS);
+				    BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING);
 		if (!tm_list[i]) {
 			ret = -ENOMEM;
 			goto free_tms;
diff --git a/fs/btrfs/tree-mod-log.h b/fs/btrfs/tree-mod-log.h
index 12605d19621b..8cffe0bc2a39 100644
--- a/fs/btrfs/tree-mod-log.h
+++ b/fs/btrfs/tree-mod-log.h
@@ -32,7 +32,7 @@ int btrfs_tree_mod_log_insert_root(struct extent_buffer *old_root,
 				   struct extent_buffer *new_root,
 				   bool log_removal);
 int btrfs_tree_mod_log_insert_key(struct extent_buffer *eb, int slot,
-				  enum btrfs_mod_log_op op, gfp_t flags);
+				  enum btrfs_mod_log_op op);
 int btrfs_tree_mod_log_free_eb(struct extent_buffer *eb);
 struct extent_buffer *btrfs_tree_mod_log_rewind(struct btrfs_fs_info *fs_info,
 						struct btrfs_path *path,
-- 
2.35.1

Re: [PATCH 2/2] btrfs: remove gfp_t flag from btrfs_tree_mod_log_insert_key()

[Filipe Manana]

On Fri, Oct 14, 2022 at 2:30 PM David Sterba <dsterba@suse.cz> wrote:
>
> On Thu, Oct 13, 2022 at 11:36:26AM +0100, fdmanana@kernel.org wrote:
> >index 8a3a14686d3e..6606534fc36a 100644
> > --- a/fs/btrfs/tree-mod-log.c
> > +++ b/fs/btrfs/tree-mod-log.c
> > @@ -220,7 +220,7 @@ static struct tree_mod_elem *alloc_tree_mod_elem(struct extent_buffer *eb,
> >  }
> >
> >  int btrfs_tree_mod_log_insert_key(struct extent_buffer *eb, int slot,
> > -                               enum btrfs_mod_log_op op, gfp_t flags)
> > +                               enum btrfs_mod_log_op op)
> >  {
> >       struct tree_mod_elem *tm;
> >       int ret;
> > @@ -228,7 +228,7 @@ int btrfs_tree_mod_log_insert_key(struct extent_buffer *eb, int slot,
> >       if (!tree_mod_need_log(eb->fs_info, eb))
> >               return 0;
> >
> > -     tm = alloc_tree_mod_elem(eb, slot, op, flags);
> > +     tm = alloc_tree_mod_elem(eb, slot, op, GFP_NOFS);
>
> And after that alloc_tree_mod_elem is also called only with GFP_NOFS.

Indeed.
Just sent a v2 with that change as well.

Thanks.

>
> >       if (!tm)
> >               return -ENOMEM;
> >

Re: [PATCH v2 0/2] btrfs: drop no longer needed atomic allocation for tree mod log operations

[David Sterba]

On Fri, Oct 14, 2022 at 02:44:31PM +0100, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> We are still doing an atomic memory allocation for tree mod log operations
> which is not needed anymore after we switch extent buffer locks to rw
> semaphores. This replaces that atomic allocation with a GFP_NOFS one, and
> then removes redundant gfp_t argument for btrfs_tree_mod_log_insert_key().
> 
> V2: Updated patch 2/2 to also remove the allocation flag from
>     alloc_tree_mod_elem().

Updated to v2 in misc-next, thanks.