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Message-Id: <1294189270-16733-7-git-send-email-tytso@mit.edu>
Date: Tue, 4 Jan 2011 20:01:10 -0500
From: Theodore Ts'o <tytso@....edu>
To: Ext4 Developers List <linux-ext4@...r.kernel.org>
Cc: Theodore Ts'o <tytso@....edu>
Subject: [PATCH 6/6] 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@....edu>
---
fs/ext4/ext4.h | 2 +-
fs/ext4/ext4_jbd2.h | 2 +-
fs/ext4/file.c | 19 +++++++++++++++++++
fs/ext4/inode.c | 15 +++++++++++----
fs/ext4/super.c | 16 +++++++---------
fs/jbd2/journal.c | 20 +++++++++++++-------
include/linux/jbd2.h | 20 ++++++++++++++++++--
7 files changed, 70 insertions(+), 24 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 8a2603d..50f35e8 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -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;
/*
diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
index b0bd792..d8b992e 100644
--- a/fs/ext4/ext4_jbd2.h
+++ b/fs/ext4/ext4_jbd2.h
@@ -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;
}
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 5a5c55d..45a656f 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -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 +128,24 @@ 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);
+ }
+ spin_unlock(&inode->i_lock);
+ }
return dquot_file_open(inode, filp);
}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 2d60028..de3f2e3 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -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);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f5960d6..7f99ac7 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -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 = 0;
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_JOURNAL(inode) && 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 = 0;
+ }
}
static inline void ext4_show_quota_options(struct seq_file *seq,
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_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);
+
}
/*
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 2ae86aa..27e79c2 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -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);
--
1.7.3.1
--
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