Patch "ext4: factor out __es_alloc_extent() and __es_free_extent()" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ext4: factor out __es_alloc_extent() and __es_free_extent()

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ext4-factor-out-__es_alloc_extent-and-__es_free_exte.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 3a95c0d4b9186ca1e7c119fe84485f11d0c9c7fe
Author: Baokun Li <libaokun1@xxxxxxxxxx>
Date:   Mon Apr 24 11:38:37 2023 +0800

    ext4: factor out __es_alloc_extent() and __es_free_extent()
    
    [ Upstream commit 73a2f033656be11298912201ad50615307b4477a ]
    
    Factor out __es_alloc_extent() and __es_free_extent(), which only allocate
    and free extent_status in these two helpers.
    
    The ext4_es_alloc_extent() function is split into __es_alloc_extent()
    and ext4_es_init_extent(). In __es_alloc_extent() we allocate memory using
    GFP_KERNEL | __GFP_NOFAIL | __GFP_ZERO if the memory allocation cannot
    fail, otherwise we use GFP_ATOMIC. and the ext4_es_init_extent() is used to
    initialize extent_status and update related variables after a successful
    allocation.
    
    This is to prepare for the use of pre-allocated extent_status later.
    
    Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
    Reviewed-by: Jan Kara <jack@xxxxxxx>
    Link: https://lore.kernel.org/r/20230424033846.4732-4-libaokun1@xxxxxxxxxx
    Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
    Stable-dep-of: 8e387c89e96b ("ext4: make sure allocate pending entry not fail")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 59812c5bbe1ba..dfabb15afd3dd 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -452,14 +452,17 @@ static inline bool ext4_es_must_keep(struct extent_status *es)
 	return false;
 }
 
-static struct extent_status *
-ext4_es_alloc_extent(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t len,
-		     ext4_fsblk_t pblk)
+static inline struct extent_status *__es_alloc_extent(bool nofail)
+{
+	if (!nofail)
+		return kmem_cache_alloc(ext4_es_cachep, GFP_ATOMIC);
+
+	return kmem_cache_zalloc(ext4_es_cachep, GFP_KERNEL | __GFP_NOFAIL);
+}
+
+static void ext4_es_init_extent(struct inode *inode, struct extent_status *es,
+		ext4_lblk_t lblk, ext4_lblk_t len, ext4_fsblk_t pblk)
 {
-	struct extent_status *es;
-	es = kmem_cache_alloc(ext4_es_cachep, GFP_ATOMIC);
-	if (es == NULL)
-		return NULL;
 	es->es_lblk = lblk;
 	es->es_len = len;
 	es->es_pblk = pblk;
@@ -474,8 +477,11 @@ ext4_es_alloc_extent(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t len,
 
 	EXT4_I(inode)->i_es_all_nr++;
 	percpu_counter_inc(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
+}
 
-	return es;
+static inline void __es_free_extent(struct extent_status *es)
+{
+	kmem_cache_free(ext4_es_cachep, es);
 }
 
 static void ext4_es_free_extent(struct inode *inode, struct extent_status *es)
@@ -492,7 +498,7 @@ static void ext4_es_free_extent(struct inode *inode, struct extent_status *es)
 					s_es_stats.es_stats_shk_cnt);
 	}
 
-	kmem_cache_free(ext4_es_cachep, es);
+	__es_free_extent(es);
 }
 
 /*
@@ -794,10 +800,12 @@ static int __es_insert_extent(struct inode *inode, struct extent_status *newes)
 		}
 	}
 
-	es = ext4_es_alloc_extent(inode, newes->es_lblk, newes->es_len,
-				  newes->es_pblk);
+	es = __es_alloc_extent(false);
 	if (!es)
 		return -ENOMEM;
+	ext4_es_init_extent(inode, es, newes->es_lblk, newes->es_len,
+			    newes->es_pblk);
+
 	rb_link_node(&es->rb_node, parent, p);
 	rb_insert_color(&es->rb_node, &tree->root);