2008-05-13 00:23:51

by Andrew Morton

[permalink] [raw]
Subject: + jbd-eliminate-duplicated-code-in-revocation-table-init-destroy-functions.patch added to -mm tree


The patch titled
jbd: eliminate duplicated code in revocation table init/destroy functions
has been added to the -mm tree. Its filename is
jbd-eliminate-duplicated-code-in-revocation-table-init-destroy-functions.patch

Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/SubmitChecklist when testing your code ***

See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this

The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/

------------------------------------------------------
Subject: jbd: eliminate duplicated code in revocation table init/destroy functions
From: "Duane Griffin" <[email protected]>

The revocation table initialisation/destruction code is repeated for each
of the two revocation tables stored in the journal. Refactoring the
duplicated code into functions is tidier, simplifies the logic in
initialisation in particular, and slightly reduces the code size.

There should not be any functional change.

Signed-off-by: Duane Griffin <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

fs/jbd/revoke.c | 127 ++++++++++++++++++----------------------------
1 file changed, 51 insertions(+), 76 deletions(-)

diff -puN fs/jbd/revoke.c~jbd-eliminate-duplicated-code-in-revocation-table-init-destroy-functions fs/jbd/revoke.c
--- a/fs/jbd/revoke.c~jbd-eliminate-duplicated-code-in-revocation-table-init-destroy-functions
+++ a/fs/jbd/revoke.c
@@ -195,109 +195,84 @@ void journal_destroy_revoke_caches(void)
revoke_table_cache = NULL;
}

-/* Initialise the revoke table for a given journal to a given size. */
-
-int journal_init_revoke(journal_t *journal, int hash_size)
+static struct jbd_revoke_table_s *journal_init_revoke_table(int hash_size)
{
- int shift, tmp;
+ int shift = 0;
+ int tmp = hash_size;
+ struct jbd_revoke_table_s *table;

- J_ASSERT (journal->j_revoke_table[0] == NULL);
+ table = kmem_cache_alloc(revoke_table_cache, GFP_KERNEL);
+ if (!table)
+ goto out;

- shift = 0;
- tmp = hash_size;
while((tmp >>= 1UL) != 0UL)
shift++;

- journal->j_revoke_table[0] = kmem_cache_alloc(revoke_table_cache, GFP_KERNEL);
- if (!journal->j_revoke_table[0])
- return -ENOMEM;
- journal->j_revoke = journal->j_revoke_table[0];
-
- /* Check that the hash_size is a power of two */
- J_ASSERT(is_power_of_2(hash_size));
-
- journal->j_revoke->hash_size = hash_size;
-
- journal->j_revoke->hash_shift = shift;
-
- journal->j_revoke->hash_table =
+ table->hash_size = hash_size;
+ table->hash_shift = shift;
+ table->hash_table =
kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL);
- if (!journal->j_revoke->hash_table) {
- kmem_cache_free(revoke_table_cache, journal->j_revoke_table[0]);
- journal->j_revoke = NULL;
- return -ENOMEM;
+ if (!table->hash_table) {
+ kmem_cache_free(revoke_table_cache, table);
+ table = NULL;
+ goto out;
}

for (tmp = 0; tmp < hash_size; tmp++)
- INIT_LIST_HEAD(&journal->j_revoke->hash_table[tmp]);
+ INIT_LIST_HEAD(&table->hash_table[tmp]);
+
+out:
+ return table;
+}
+
+static void journal_destroy_revoke_table(struct jbd_revoke_table_s *table)
+{
+ int i;
+ struct list_head *hash_list;

- journal->j_revoke_table[1] = kmem_cache_alloc(revoke_table_cache, GFP_KERNEL);
- if (!journal->j_revoke_table[1]) {
- kfree(journal->j_revoke_table[0]->hash_table);
- kmem_cache_free(revoke_table_cache, journal->j_revoke_table[0]);
- return -ENOMEM;
+ for (i = 0; i < table->hash_size; i++) {
+ hash_list = &table->hash_table[i];
+ J_ASSERT(list_empty(hash_list));
}

- journal->j_revoke = journal->j_revoke_table[1];
+ kfree(table->hash_table);
+ kmem_cache_free(revoke_table_cache, table);
+}

- /* Check that the hash_size is a power of two */
+/* Initialise the revoke table for a given journal to a given size. */
+int journal_init_revoke(journal_t *journal, int hash_size)
+{
+ J_ASSERT(journal->j_revoke_table[0] == NULL);
J_ASSERT(is_power_of_2(hash_size));

- journal->j_revoke->hash_size = hash_size;
+ journal->j_revoke_table[0] = journal_init_revoke_table(hash_size);
+ if (!journal->j_revoke_table[0])
+ goto fail0;

- journal->j_revoke->hash_shift = shift;
+ journal->j_revoke_table[1] = journal_init_revoke_table(hash_size);
+ if (!journal->j_revoke_table[1])
+ goto fail1;

- journal->j_revoke->hash_table =
- kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL);
- if (!journal->j_revoke->hash_table) {
- kfree(journal->j_revoke_table[0]->hash_table);
- kmem_cache_free(revoke_table_cache, journal->j_revoke_table[0]);
- kmem_cache_free(revoke_table_cache, journal->j_revoke_table[1]);
- journal->j_revoke = NULL;
- return -ENOMEM;
- }
-
- for (tmp = 0; tmp < hash_size; tmp++)
- INIT_LIST_HEAD(&journal->j_revoke->hash_table[tmp]);
+ journal->j_revoke = journal->j_revoke_table[1];

spin_lock_init(&journal->j_revoke_lock);

return 0;
-}

-/* Destoy a journal's revoke table. The table must already be empty! */
+fail1:
+ journal_destroy_revoke_table(journal->j_revoke_table[0]);
+fail0:
+ return -ENOMEM;
+}

+/* Destroy a journal's revoke table. The table must already be empty! */
void journal_destroy_revoke(journal_t *journal)
{
- struct jbd_revoke_table_s *table;
- struct list_head *hash_list;
- int i;
-
- table = journal->j_revoke_table[0];
- if (!table)
- return;
-
- for (i=0; i<table->hash_size; i++) {
- hash_list = &table->hash_table[i];
- J_ASSERT (list_empty(hash_list));
- }
-
- kfree(table->hash_table);
- kmem_cache_free(revoke_table_cache, table);
- journal->j_revoke = NULL;
-
- table = journal->j_revoke_table[1];
- if (!table)
- return;
-
- for (i=0; i<table->hash_size; i++) {
- hash_list = &table->hash_table[i];
- J_ASSERT (list_empty(hash_list));
- }