LinuxLists.cc - [PATCH 00/39] drop null test before destroy functions

2015-09-13 12:14:53

Subject: [PATCH 00/39] drop null test before destroy functions

2015-09-13 12:15:12

by Julia Lawall

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Subject: [PATCH 19/39] jbd2: drop null test before destroy functions

Remove unneeded NULL test.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x;
@@

-if (x != NULL)
\(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);

@@
expression x;
@@

-if (x != NULL) {
\(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
x = NULL;
-}
// </smpl>

Signed-off-by: Julia Lawall <[email protected]>

---
fs/jbd2/journal.c | 15 +++++----------
fs/jbd2/revoke.c | 12 ++++--------
fs/jbd2/transaction.c | 6 ++----
3 files changed, 11 insertions(+), 22 deletions(-)

diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 6b8338e..ab26122 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -51,10 +51,8 @@ int __init jbd2_journal_init_transaction_cache(void)

void jbd2_journal_destroy_transaction_cache(void)
{
- if (transaction_cache) {
- kmem_cache_destroy(transaction_cache);
- transaction_cache = NULL;
- }
+ kmem_cache_destroy(transaction_cache);
+ transaction_cache = NULL;
}

void jbd2_journal_free_transaction(transaction_t *transaction)
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 8270fe9..6b8c2c5 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -2240,8 +2240,7 @@ static void jbd2_journal_destroy_slabs(void)
int i;

for (i = 0; i < JBD2_MAX_SLABS; i++) {
- if (jbd2_slab[i])
- kmem_cache_destroy(jbd2_slab[i]);
+ kmem_cache_destroy(jbd2_slab[i]);
jbd2_slab[i] = NULL;
}
}
@@ -2360,10 +2359,8 @@ static int jbd2_journal_init_journal_head_cache(void)

static void jbd2_journal_destroy_journal_head_cache(void)
{
- if (jbd2_journal_head_cache) {
- kmem_cache_destroy(jbd2_journal_head_cache);
- jbd2_journal_head_cache = NULL;
- }
+ kmem_cache_destroy(jbd2_journal_head_cache);
+ jbd2_journal_head_cache = NULL;
}

/*
@@ -2621,10 +2618,8 @@ static int __init jbd2_journal_init_handle_cache(void)

static void jbd2_journal_destroy_handle_cache(void)
{
- if (jbd2_handle_cache)
- kmem_cache_destroy(jbd2_handle_cache);
- if (jbd2_inode_cache)
- kmem_cache_destroy(jbd2_inode_cache);
+ kmem_cache_destroy(jbd2_handle_cache);
+ kmem_cache_destroy(jbd2_inode_cache);

}

diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
index 0abf2e7..1e77a9d 100644
--- a/fs/jbd2/revoke.c
+++ b/fs/jbd2/revoke.c
@@ -183,14 +183,10 @@ static struct jbd2_revoke_record_s *find_revoke_record(journal_t *journal,

void jbd2_journal_destroy_revoke_caches(void)
{
- if (jbd2_revoke_record_cache) {
- kmem_cache_destroy(jbd2_revoke_record_cache);
- jbd2_revoke_record_cache = NULL;
- }
- if (jbd2_revoke_table_cache) {
- kmem_cache_destroy(jbd2_revoke_table_cache);
- jbd2_revoke_table_cache = NULL;
- }
+ kmem_cache_destroy(jbd2_revoke_record_cache);
+ jbd2_revoke_record_cache = NULL;
+ kmem_cache_destroy(jbd2_revoke_table_cache);
+ jbd2_revoke_table_cache = NULL;
}

int __init jbd2_journal_init_revoke_caches(void)

2015-09-13 12:15:00

by Julia Lawall

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Subject: [PATCH 07/39] fs: ext4: drop null test before destroy functions

Remove unneeded NULL test.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@ expression x; @@
-if (x != NULL)
\(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
// </smpl>

Signed-off-by: Julia Lawall <[email protected]>

---
fs/ext4/crypto.c | 9 +++------
fs/ext4/extents_status.c | 3 +--
fs/ext4/mballoc.c | 3 +--
3 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 26724ae..42096d3 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -161,8 +161,7 @@ int __init ext4_init_es(void)

void ext4_exit_es(void)
{
- if (ext4_es_cachep)
- kmem_cache_destroy(ext4_es_cachep);
+ kmem_cache_destroy(ext4_es_cachep);
}

void ext4_es_init_tree(struct ext4_es_tree *tree)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 34b610e..b5adfb9 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2520,8 +2520,7 @@ static void ext4_groupinfo_destroy_slabs(void)
int i;

for (i = 0; i < NR_GRPINFO_CACHES; i++) {
- if (ext4_groupinfo_caches[i])
- kmem_cache_destroy(ext4_groupinfo_caches[i]);
+ kmem_cache_destroy(ext4_groupinfo_caches[i]);
ext4_groupinfo_caches[i] = NULL;
}
}
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index 4573155..e4d6d30 100644
--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -153,17 +153,14 @@ void ext4_exit_crypto(void)
list_for_each_entry_safe(pos, n, &ext4_free_crypto_ctxs, free_list)
kmem_cache_free(ext4_crypto_ctx_cachep, pos);
INIT_LIST_HEAD(&ext4_free_crypto_ctxs);
- if (ext4_bounce_page_pool)
- mempool_destroy(ext4_bounce_page_pool);
+ mempool_destroy(ext4_bounce_page_pool);
ext4_bounce_page_pool = NULL;
if (ext4_read_workqueue)
destroy_workqueue(ext4_read_workqueue);
ext4_read_workqueue = NULL;
- if (ext4_crypto_ctx_cachep)
- kmem_cache_destroy(ext4_crypto_ctx_cachep);
+ kmem_cache_destroy(ext4_crypto_ctx_cachep);
ext4_crypto_ctx_cachep = NULL;
- if (ext4_crypt_info_cachep)
- kmem_cache_destroy(ext4_crypt_info_cachep);
+ kmem_cache_destroy(ext4_crypt_info_cachep);
ext4_crypt_info_cachep = NULL;
}

2015-09-14 11:55:06

by SF Markus Elfring

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Subject: Re: [PATCH 00/39] drop null test before destroy functions

> Recent commits to kernel/git/torvalds/linux.git have made the following
> functions able to tolerate NULL arguments:
>
> kmem_cache_destroy (commit 3942d29918522)
> mempool_destroy (commit 4e3ca3e033d1)
> dma_pool_destroy (commit 44d7175da6ea)

How do you think about to extend an other SmPL script?

Related topic:
scripts/coccinelle/free: Delete NULL test before freeing functions
https://systeme.lip6.fr/pipermail/cocci/2015-May/001960.html
https://www.mail-archive.com/[email protected]/msg01855.html

> If these changes are OK, I will address the remainder later.

Would anybody like to reuse my general SmPL approach for similar source
code clean-up?

Regards,
Markus