Commit 8aefcd55 authored by Theodore Ts'o's avatar Theodore Ts'o
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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: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 353eb83c
......@@ -811,7 +811,7 @@ struct ext4_inode_info {
*/
struct rw_semaphore i_data_sem;
struct inode vfs_inode;
struct jbd2_inode jinode;
struct jbd2_inode *jinode;
struct ext4_ext_cache i_cached_extent;
/*
......
......@@ -253,7 +253,7 @@ static inline int ext4_journal_force_commit(journal_t *journal)
static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode)
{
if (ext4_handle_valid(handle))
return jbd2_journal_file_inode(handle, &EXT4_I(inode)->jinode);
return jbd2_journal_file_inode(handle, EXT4_I(inode)->jinode);
return 0;
}
......
......@@ -104,6 +104,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
{
struct super_block *sb = inode->i_sb;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct ext4_inode_info *ei = EXT4_I(inode);
struct vfsmount *mnt = filp->f_path.mnt;
struct path path;
char buf[64], *cp;
......@@ -127,6 +128,27 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
ext4_mark_super_dirty(sb);
}
}
/*
* Set up the jbd2_inode if we are opening the inode for
* writing and the journal is present
*/
if (sbi->s_journal && !ei->jinode && (filp->f_mode & FMODE_WRITE)) {
struct jbd2_inode *jinode = jbd2_alloc_inode(GFP_KERNEL);
spin_lock(&inode->i_lock);
if (!ei->jinode) {
if (!jinode) {
spin_unlock(&inode->i_lock);
return -ENOMEM;
}
ei->jinode = jinode;
jbd2_journal_init_jbd_inode(ei->jinode, inode);
jinode = NULL;
}
spin_unlock(&inode->i_lock);
if (unlikely(jinode != NULL))
jbd2_free_inode(jinode);
}
return dquot_file_open(inode, filp);
}
......
......@@ -55,10 +55,17 @@ static inline int ext4_begin_ordered_truncate(struct inode *inode,
loff_t new_size)
{
trace_ext4_begin_ordered_truncate(inode, new_size);
return jbd2_journal_begin_ordered_truncate(
EXT4_SB(inode->i_sb)->s_journal,
&EXT4_I(inode)->jinode,
new_size);
/*
* If jinode is zero, then we never opened the file for
* writing, so there's no need to call
* jbd2_journal_begin_ordered_truncate() since there's no
* outstanding writes we need to flush.
*/
if (!EXT4_I(inode)->jinode)
return 0;
return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode),
EXT4_I(inode)->jinode,
new_size);
}
static void ext4_invalidatepage(struct page *page, unsigned long offset);
......@@ -4054,7 +4061,7 @@ int ext4_block_truncate_page(handle_t *handle,
if (ext4_should_journal_data(inode)) {
err = ext4_handle_dirty_metadata(handle, inode, bh);
} else {
if (ext4_should_order_data(inode))
if (ext4_should_order_data(inode) && EXT4_I(inode)->jinode)
err = ext4_jbd2_file_inode(handle, inode);
mark_buffer_dirty(bh);
}
......
......@@ -818,12 +818,6 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
INIT_LIST_HEAD(&ei->i_prealloc_list);
spin_lock_init(&ei->i_prealloc_lock);
/*
* Note: We can be called before EXT4_SB(sb)->s_journal is set,
* therefore it can be null here. Don't check it, just initialize
* jinode.
*/
jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
ei->i_reserved_data_blocks = 0;
ei->i_reserved_meta_blocks = 0;
ei->i_allocated_meta_blocks = 0;
......@@ -832,6 +826,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
#ifdef CONFIG_QUOTA
ei->i_reserved_quota = 0;
#endif
ei->jinode = NULL;
INIT_LIST_HEAD(&ei->i_completed_io_list);
spin_lock_init(&ei->i_completed_io_lock);
ei->cur_aio_dio = NULL;
......@@ -900,9 +895,12 @@ void ext4_clear_inode(struct inode *inode)
end_writeback(inode);
dquot_drop(inode);
ext4_discard_preallocations(inode);
if (EXT4_JOURNAL(inode))
jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
&EXT4_I(inode)->jinode);
if (EXT4_I(inode)->jinode) {
jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
EXT4_I(inode)->jinode);
jbd2_free_inode(EXT4_I(inode)->jinode);
EXT4_I(inode)->jinode = NULL;
}
}
static inline void ext4_show_quota_options(struct seq_file *seq,
......
......@@ -94,6 +94,7 @@ EXPORT_SYMBOL(jbd2_journal_file_inode);
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 @@ static void __exit jbd2_remove_jbd_stats_proc_entry(void)
#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 @@ 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);
}
/*
......
......@@ -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);
......
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