btrfs: scrub: remove the unnecessary path parameter for scrub_raid56_parity()

In function scrub_stripe() we allocated two btrfs_path's, one @path for
extent tree search and another @ppath for full stripe extent tree search
for RAID56.

This is totally umncessary, as the @ppath usage is completely inside
scrub_raid56_parity(), thus we can move the path allocation into
scrub_raid56_parity() completely.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index f28ae41b1df39aba85d74863717d25e36e678c6d..92fd2be6cd65f9fb59644a6acfea957ec7f43024 100644 (file)
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -2885,7 +2885,6 @@ static void scrub_parity_put(struct scrub_parity *sparity)
 static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
                                                  struct map_lookup *map,
                                                  struct btrfs_device *sdev,
-                                                 struct btrfs_path *path,
                                                  u64 logic_start,
                                                  u64 logic_end)
 {
@@ -2894,6 +2893,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
        struct btrfs_root *csum_root;
        struct btrfs_extent_item *extent;
        struct btrfs_io_context *bioc = NULL;
+       struct btrfs_path *path;
        u64 flags;
        int ret;
        int slot;
@@ -2912,6 +2912,16 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
        int extent_mirror_num;
        int stop_loop = 0;
 
+       path = btrfs_alloc_path();
+       if (!path) {
+               spin_lock(&sctx->stat_lock);
+               sctx->stat.malloc_errors++;
+               spin_unlock(&sctx->stat_lock);
+               return -ENOMEM;
+       }
+       path->search_commit_root = 1;
+       path->skip_locking = 1;
+
        ASSERT(map->stripe_len <= U32_MAX);
        nsectors = map->stripe_len >> fs_info->sectorsize_bits;
        bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
@@ -2921,6 +2931,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
                spin_lock(&sctx->stat_lock);
                sctx->stat.malloc_errors++;
                spin_unlock(&sctx->stat_lock);
+               btrfs_free_path(path);
                return -ENOMEM;
        }
 
@@ -3110,7 +3121,7 @@ out:
        scrub_wr_submit(sctx);
        mutex_unlock(&sctx->wr_lock);
 
-       btrfs_release_path(path);
+       btrfs_free_path(path);
        return ret < 0 ? ret : 0;
 }
 
@@ -3160,7 +3171,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
                                           int num, u64 base, u64 length,
                                           struct btrfs_block_group *cache)
 {
-       struct btrfs_path *path, *ppath;
+       struct btrfs_path *path;
        struct btrfs_fs_info *fs_info = sctx->fs_info;
        struct btrfs_root *root;
        struct btrfs_root *csum_root;
@@ -3222,12 +3233,6 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
        if (!path)
                return -ENOMEM;
 
-       ppath = btrfs_alloc_path();
-       if (!ppath) {
-               btrfs_free_path(path);
-               return -ENOMEM;
-       }
-
        /*
         * work on commit root. The related disk blocks are static as
         * long as COW is applied. This means, it is save to rewrite
@@ -3236,8 +3241,6 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
        path->search_commit_root = 1;
        path->skip_locking = 1;
 
-       ppath->search_commit_root = 1;
-       ppath->skip_locking = 1;
        /*
         * trigger the readahead for extent tree csum tree and wait for
         * completion. During readahead, the scrub is officially paused
@@ -3340,7 +3343,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
                                stripe_logical += base;
                                stripe_end = stripe_logical + increment;
                                ret = scrub_raid56_parity(sctx, map, scrub_dev,
-                                                         ppath, stripe_logical,
+                                                         stripe_logical,
                                                          stripe_end);
                                if (ret)
                                        goto out;
@@ -3511,7 +3514,7 @@ loop:
                                                stripe_end = stripe_logical +
                                                                increment;
                                                ret = scrub_raid56_parity(sctx,
-                                                       map, scrub_dev, ppath,
+                                                       map, scrub_dev,
                                                        stripe_logical,
                                                        stripe_end);
                                                if (ret)
@@ -3558,7 +3561,6 @@ out:
 
        blk_finish_plug(&plug);
        btrfs_free_path(path);
-       btrfs_free_path(ppath);
 
        if (sctx->is_dev_replace && ret >= 0) {
                int ret2;