[PATCH] fs/ext4: remove redundant initialization of variable busy
From: Wen Yang <hidden>
Date: 2021-04-21 15:55:47
Also in:
lkml
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
The variable status is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and could be removed. Also put the variable declarations into reverse christmas tree order. Finally, we add the log printing and ext4_mb_show_pa() for troubleshooting, they are enabled only when CONFIG_EXT4_DEBUG is set. Signed-off-by: Wen Yang <redacted> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Baoyou Xie <redacted> Cc: linux-ext4@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- fs/ext4/mballoc.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index a02fadf..1402b14 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c@@ -351,6 +351,8 @@ static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap, ext4_group_t group); static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac); +static inline void ext4_mb_show_pa(struct super_block *sb); + /* * The algorithm using this percpu seq counter goes below: * 1. We sample the percpu discard_pa_seq counter before trying for block
@@ -4217,9 +4219,9 @@ static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac) struct ext4_prealloc_space *pa, *tmp; struct list_head list; struct ext4_buddy e4b; + int free_total = 0; + int busy, free; int err; - int busy = 0; - int free, free_total = 0; mb_debug(sb, "discard preallocation for group %u\n", group); if (list_empty(&grp->bb_prealloc_list))
@@ -4247,6 +4249,7 @@ static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac) INIT_LIST_HEAD(&list); repeat: + busy = 0; free = 0; ext4_lock_group(sb, group); list_for_each_entry_safe(pa, tmp,
@@ -4255,6 +4258,8 @@ static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac) if (atomic_read(&pa->pa_count)) { spin_unlock(&pa->pa_lock); busy = 1; + mb_debug(sb, "used pa while discarding for group %u\n", group); + ext4_mb_show_pa(sb); continue; } if (pa->pa_deleted) {
@@ -4300,7 +4305,6 @@ static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac) if (free_total < needed && busy) { ext4_unlock_group(sb, group); cond_resched(); - busy = 0; goto repeat; } ext4_unlock_group(sb, group);
--
1.8.3.1