ext4: dynamically allocate the jbd2_inode in ext4_inode_info as necessary
Replace the jbd2_inode structure (which is 48 bytes) with a pointer
and only allocate the jbd2_inode when it is needed --- that is, when
the file system has a journal present and the inode has been opened
for writing. This allows us to further slim down the ext4_inode_info
structure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 2447bd8..9e46869 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -94,6 +94,7 @@
EXPORT_SYMBOL(jbd2_journal_init_jbd_inode);
EXPORT_SYMBOL(jbd2_journal_release_jbd_inode);
EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate);
+EXPORT_SYMBOL(jbd2_inode_cache);
static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
static void __journal_abort_soft (journal_t *journal, int errno);
@@ -2286,17 +2287,19 @@
#endif
-struct kmem_cache *jbd2_handle_cache;
+struct kmem_cache *jbd2_handle_cache, *jbd2_inode_cache;
static int __init journal_init_handle_cache(void)
{
- jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle",
- sizeof(handle_t),
- 0, /* offset */
- SLAB_TEMPORARY, /* flags */
- NULL); /* ctor */
+ jbd2_handle_cache = KMEM_CACHE(jbd2_journal_handle, SLAB_TEMPORARY);
if (jbd2_handle_cache == NULL) {
- printk(KERN_EMERG "JBD: failed to create handle cache\n");
+ printk(KERN_EMERG "JBD2: failed to create handle cache\n");
+ return -ENOMEM;
+ }
+ jbd2_inode_cache = KMEM_CACHE(jbd2_inode, 0);
+ if (jbd2_inode_cache == NULL) {
+ printk(KERN_EMERG "JBD2: failed to create inode cache\n");
+ kmem_cache_destroy(jbd2_handle_cache);
return -ENOMEM;
}
return 0;
@@ -2306,6 +2309,9 @@
{
if (jbd2_handle_cache)
kmem_cache_destroy(jbd2_handle_cache);
+ if (jbd2_inode_cache)
+ kmem_cache_destroy(jbd2_inode_cache);
+
}
/*