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>
This commit is contained in:
Theodore Ts'o
2011-01-10 12:29:43 -05:00
parent 353eb83c14
commit 8aefcd557d
7 changed files with 74 additions and 25 deletions

View File

@@ -94,7 +94,7 @@ extern void jbd2_free(void *ptr, size_t size);
*
* This is an opaque datatype.
**/
typedef struct handle_s handle_t; /* Atomic operation type */
typedef struct jbd2_journal_handle handle_t; /* Atomic operation type */
/**
@@ -416,7 +416,7 @@ struct jbd2_revoke_table_s;
* in so it can be fixed later.
*/
struct handle_s
struct jbd2_journal_handle
{
/* Which compound transaction is this update a part of? */
transaction_t *h_transaction;
@@ -1158,6 +1158,22 @@ static inline void jbd2_free_handle(handle_t *handle)
kmem_cache_free(jbd2_handle_cache, handle);
}
/*
* jbd2_inode management (optional, for those file systems that want to use
* dynamically allocated jbd2_inode structures)
*/
extern struct kmem_cache *jbd2_inode_cache;
static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags)
{
return kmem_cache_alloc(jbd2_inode_cache, gfp_flags);
}
static inline void jbd2_free_inode(struct jbd2_inode *jinode)
{
kmem_cache_free(jbd2_inode_cache, jinode);
}
/* Primary revoke support */
#define JOURNAL_REVOKE_DEFAULT_HASH 256
extern int jbd2_journal_init_revoke(journal_t *, int);