ext4: make some fast commit functions reuse extents path

The ext4_find_extent() can update the extent path so that it does not have
to allocate and free the path repeatedly, thus reducing the consumption of
memory allocation and freeing in the following functions:

    ext4_ext_clear_bb
    ext4_ext_replay_set_iblocks
    ext4_fc_replay_add_range
    ext4_fc_set_bitmaps_and_counters

No functional changes. Note that ext4_find_extent() does not support error
pointers, so in this case set path to NULL first.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20240822023545.1994557-25-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e671ad642cfb7ba066ea2349be042293f1288420..29aaa7340b09485c663189ab8c677b57417b14c3 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -6033,12 +6033,9 @@ int ext4_ext_replay_set_iblocks(struct inode *inode)
        if (IS_ERR(path))
                return PTR_ERR(path);
        ex = path[path->p_depth].p_ext;
-       if (!ex) {
-               ext4_free_ext_path(path);
+       if (!ex)
                goto out;
-       }
        end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
-       ext4_free_ext_path(path);
 
        /* Count the number of data blocks */
        cur = 0;
@@ -6064,32 +6061,28 @@ int ext4_ext_replay_set_iblocks(struct inode *inode)
        ret = skip_hole(inode, &cur);
        if (ret < 0)
                goto out;
-       path = ext4_find_extent(inode, cur, NULL, 0);
+       path = ext4_find_extent(inode, cur, path, 0);
        if (IS_ERR(path))
                goto out;
        numblks += path->p_depth;
-       ext4_free_ext_path(path);
        while (cur < end) {
-               path = ext4_find_extent(inode, cur, NULL, 0);
+               path = ext4_find_extent(inode, cur, path, 0);
                if (IS_ERR(path))
                        break;
                ex = path[path->p_depth].p_ext;
-               if (!ex) {
-                       ext4_free_ext_path(path);
-                       return 0;
-               }
+               if (!ex)
+                       goto cleanup;
+
                cur = max(cur + 1, le32_to_cpu(ex->ee_block) +
                                        ext4_ext_get_actual_len(ex));
                ret = skip_hole(inode, &cur);
-               if (ret < 0) {
-                       ext4_free_ext_path(path);
+               if (ret < 0)
                        break;
-               }
-               path2 = ext4_find_extent(inode, cur, NULL, 0);
-               if (IS_ERR(path2)) {
-                       ext4_free_ext_path(path);
+
+               path2 = ext4_find_extent(inode, cur, path2, 0);
+               if (IS_ERR(path2))
                        break;
-               }
+
                for (i = 0; i <= max(path->p_depth, path2->p_depth); i++) {
                        cmp1 = cmp2 = 0;
                        if (i <= path->p_depth)
@@ -6101,13 +6094,14 @@ int ext4_ext_replay_set_iblocks(struct inode *inode)
                        if (cmp1 != cmp2 && cmp2 != 0)
                                numblks++;
                }
-               ext4_free_ext_path(path);
-               ext4_free_ext_path(path2);
        }
 
 out:
        inode->i_blocks = numblks << (inode->i_sb->s_blocksize_bits - 9);
        ext4_mark_inode_dirty(NULL, inode);
+cleanup:
+       ext4_free_ext_path(path);
+       ext4_free_ext_path(path2);
        return 0;
 }
 
@@ -6128,12 +6122,9 @@ int ext4_ext_clear_bb(struct inode *inode)
        if (IS_ERR(path))
                return PTR_ERR(path);
        ex = path[path->p_depth].p_ext;
-       if (!ex) {
-               ext4_free_ext_path(path);
-               return 0;
-       }
+       if (!ex)
+               goto out;
        end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
-       ext4_free_ext_path(path);
 
        cur = 0;
        while (cur < end) {
@@ -6143,16 +6134,16 @@ int ext4_ext_clear_bb(struct inode *inode)
                if (ret < 0)
                        break;
                if (ret > 0) {
-                       path = ext4_find_extent(inode, map.m_lblk, NULL, 0);
-                       if (!IS_ERR_OR_NULL(path)) {
+                       path = ext4_find_extent(inode, map.m_lblk, path, 0);
+                       if (!IS_ERR(path)) {
                                for (j = 0; j < path->p_depth; j++) {
-
                                        ext4_mb_mark_bb(inode->i_sb,
                                                        path[j].p_block, 1, false);
                                        ext4_fc_record_regions(inode->i_sb, inode->i_ino,
                                                        0, path[j].p_block, 1, 1);
                                }
-                               ext4_free_ext_path(path);
+                       } else {
+                               path = NULL;
                        }
                        ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, false);
                        ext4_fc_record_regions(inode->i_sb, inode->i_ino,
@@ -6161,5 +6152,7 @@ int ext4_ext_clear_bb(struct inode *inode)
                cur = cur + map.m_len;
        }
 
+out:
+       ext4_free_ext_path(path);
        return 0;
 }

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index afcb2e5cdac7220a1f9e1a4d9c5c82f5d0968088..eaa5f5b51f500bf6de3ccd97f1f75c64bfa3907b 100644 (file)
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -1792,7 +1792,7 @@ static int ext4_fc_replay_add_range(struct super_block *sb,
 
                if (ret == 0) {
                        /* Range is not mapped */
-                       path = ext4_find_extent(inode, cur, NULL, 0);
+                       path = ext4_find_extent(inode, cur, path, 0);
                        if (IS_ERR(path))
                                goto out;
                        memset(&newex, 0, sizeof(newex));
@@ -1808,7 +1808,6 @@ static int ext4_fc_replay_add_range(struct super_block *sb,
                        up_write((&EXT4_I(inode)->i_data_sem));
                        if (IS_ERR(path))
                                goto out;
-                       ext4_free_ext_path(path);
                        goto next;
                }
 
@@ -1856,6 +1855,7 @@ next:
        ext4_ext_replay_shrink_inode(inode, i_size_read(inode) >>
                                        sb->s_blocksize_bits);
 out:
+       ext4_free_ext_path(path);
        iput(inode);
        return 0;
 }
@@ -1956,12 +1956,13 @@ static void ext4_fc_set_bitmaps_and_counters(struct super_block *sb)
                                break;
 
                        if (ret > 0) {
-                               path = ext4_find_extent(inode, map.m_lblk, NULL, 0);
+                               path = ext4_find_extent(inode, map.m_lblk, path, 0);
                                if (!IS_ERR(path)) {
                                        for (j = 0; j < path->p_depth; j++)
                                                ext4_mb_mark_bb(inode->i_sb,
                                                        path[j].p_block, 1, true);
-                                       ext4_free_ext_path(path);
+                               } else {
+                                       path = NULL;
                                }
                                cur += ret;
                                ext4_mb_mark_bb(inode->i_sb, map.m_pblk,
@@ -1972,6 +1973,8 @@ static void ext4_fc_set_bitmaps_and_counters(struct super_block *sb)
                }
                iput(inode);
        }
+
+       ext4_free_ext_path(path);
 }
 
 /*