From 71f2be213a0009098819e5c04f75ff19f84f2122 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Wed, 23 Dec 2009 07:45:44 -0500 Subject: ext4: Add new tracepoint for jbd2_cleanup_journal_tail Signed-off-by: "Theodore Ts'o" --- fs/jbd2/checkpoint.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/jbd2') diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c index 886849370950..30beb11ef928 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -507,6 +507,7 @@ int jbd2_cleanup_journal_tail(journal_t *journal) if (blocknr < journal->j_tail) freed = freed + journal->j_last - journal->j_first; + trace_jbd2_cleanup_journal_tail(journal, first_tid, blocknr, freed); jbd_debug(1, "Cleaning journal tail from %d to %d (offset %lu), " "freeing %lu\n", -- cgit v1.2.3 From d2eecb03936878ec574ade5532fa83df7d75dde7 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 7 Dec 2009 10:36:20 -0500 Subject: ext4: Use slab allocator for sub-page sized allocations Now that the SLUB seems to be fixed so that it respects the requested alignment, use kmem_cache_alloc() to allocator if the block size of the buffer heads to be allocated is less than the page size. Previously, we were using 16k page on a Power system for each buffer, even when the file system was using 1k or 4k block size. Signed-off-by: "Theodore Ts'o" --- fs/jbd2/journal.c | 132 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/jbd2.h | 11 +---- 2 files changed, 134 insertions(+), 9 deletions(-) (limited to 'fs/jbd2') diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index ac0d027595d0..c03d4dce4d76 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -39,6 +39,8 @@ #include #include #include +#include +#include #define CREATE_TRACE_POINTS #include @@ -93,6 +95,7 @@ EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate); static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *); static void __journal_abort_soft (journal_t *journal, int errno); +static int jbd2_journal_create_slab(size_t slab_size); /* * Helper function used to manage commit timeouts @@ -1248,6 +1251,13 @@ int jbd2_journal_load(journal_t *journal) } } + /* + * Create a slab for this blocksize + */ + err = jbd2_journal_create_slab(be32_to_cpu(sb->s_blocksize)); + if (err) + return err; + /* Let the recovery code check whether it needs to recover any * data from the journal. */ if (jbd2_journal_recover(journal)) @@ -1806,6 +1816,127 @@ size_t journal_tag_bytes(journal_t *journal) return JBD2_TAG_SIZE32; } +/* + * JBD memory management + * + * These functions are used to allocate block-sized chunks of memory + * used for making copies of buffer_head data. Very often it will be + * page-sized chunks of data, but sometimes it will be in + * sub-page-size chunks. (For example, 16k pages on Power systems + * with a 4k block file system.) For blocks smaller than a page, we + * use a SLAB allocator. There are slab caches for each block size, + * which are allocated at mount time, if necessary, and we only free + * (all of) the slab caches when/if the jbd2 module is unloaded. For + * this reason we don't need to a mutex to protect access to + * jbd2_slab[] allocating or releasing memory; only in + * jbd2_journal_create_slab(). + */ +#define JBD2_MAX_SLABS 8 +static struct kmem_cache *jbd2_slab[JBD2_MAX_SLABS]; +static DECLARE_MUTEX(jbd2_slab_create_sem); + +static const char *jbd2_slab_names[JBD2_MAX_SLABS] = { + "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k", + "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k" +}; + + +static void jbd2_journal_destroy_slabs(void) +{ + int i; + + for (i = 0; i < JBD2_MAX_SLABS; i++) { + if (jbd2_slab[i]) + kmem_cache_destroy(jbd2_slab[i]); + jbd2_slab[i] = NULL; + } +} + +static int jbd2_journal_create_slab(size_t size) +{ + int i = order_base_2(size) - 10; + size_t slab_size; + + if (size == PAGE_SIZE) + return 0; + + if (i >= JBD2_MAX_SLABS) + return -EINVAL; + + if (unlikely(i < 0)) + i = 0; + down(&jbd2_slab_create_sem); + if (jbd2_slab[i]) { + up(&jbd2_slab_create_sem); + return 0; /* Already created */ + } + + slab_size = 1 << (i+10); + jbd2_slab[i] = kmem_cache_create(jbd2_slab_names[i], slab_size, + slab_size, 0, NULL); + up(&jbd2_slab_create_sem); + if (!jbd2_slab[i]) { + printk(KERN_EMERG "JBD2: no memory for jbd2_slab cache\n"); + return -ENOMEM; + } + return 0; +} + +static struct kmem_cache *get_slab(size_t size) +{ + int i = order_base_2(size) - 10; + + BUG_ON(i >= JBD2_MAX_SLABS); + if (unlikely(i < 0)) + i = 0; + BUG_ON(jbd2_slab[i] == 0); + return jbd2_slab[i]; +} + +void *jbd2_alloc(size_t size, gfp_t flags) +{ + void *ptr; + + BUG_ON(size & (size-1)); /* Must be a power of 2 */ + + flags |= __GFP_REPEAT; + if (size == PAGE_SIZE) + ptr = (void *)__get_free_pages(flags, 0); + else if (size > PAGE_SIZE) { + int order = get_order(size); + + if (order < 3) + ptr = (void *)__get_free_pages(flags, order); + else + ptr = vmalloc(size); + } else + ptr = kmem_cache_alloc(get_slab(size), flags); + + /* Check alignment; SLUB has gotten this wrong in the past, + * and this can lead to user data corruption! */ + BUG_ON(((unsigned long) ptr) & (size-1)); + + return ptr; +} + +void jbd2_free(void *ptr, size_t size) +{ + if (size == PAGE_SIZE) { + free_pages((unsigned long)ptr, 0); + return; + } + if (size > PAGE_SIZE) { + int order = get_order(size); + + if (order < 3) + free_pages((unsigned long)ptr, order); + else + vfree(ptr); + return; + } + kmem_cache_free(get_slab(size), ptr); +}; + /* * Journal_head storage management */ @@ -2204,6 +2335,7 @@ static void jbd2_journal_destroy_caches(void) jbd2_journal_destroy_revoke_caches(); jbd2_journal_destroy_jbd2_journal_head_cache(); jbd2_journal_destroy_handle_cache(); + jbd2_journal_destroy_slabs(); } static int __init journal_init(void) diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 638ce4554c76..8ada2a129d08 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -69,15 +69,8 @@ extern u8 jbd2_journal_enable_debug; #define jbd_debug(f, a...) /**/ #endif -static inline void *jbd2_alloc(size_t size, gfp_t flags) -{ - return (void *)__get_free_pages(flags, get_order(size)); -} - -static inline void jbd2_free(void *ptr, size_t size) -{ - free_pages((unsigned long)ptr, get_order(size)); -}; +extern void *jbd2_alloc(size_t size, gfp_t flags); +extern void jbd2_free(void *ptr, size_t size); #define JBD2_MIN_JOURNAL_BLOCKS 1024 -- cgit v1.2.3 From ba869023eac8354b17acdcff82b851ea8e7b1809 Mon Sep 17 00:00:00 2001 From: dingdinghua Date: Mon, 15 Feb 2010 16:35:42 -0500 Subject: jbd2: delay discarding buffers in journal_unmap_buffer Delay discarding buffers in journal_unmap_buffer until we know that "add to orphan" operation has definitely been committed, otherwise the log space of committing transation may be freed and reused before truncate get committed, updates may get lost if crash happens. Signed-off-by: dingdinghua Signed-off-by: "Theodore Ts'o" --- fs/jbd2/commit.c | 10 +++++----- fs/jbd2/transaction.c | 43 +++++++++++++++++++++++++++++++------------ 2 files changed, 36 insertions(+), 17 deletions(-) (limited to 'fs/jbd2') diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 1bc74b6f26d2..3ee211ed58f1 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -930,12 +930,12 @@ restart_loop: /* A buffer which has been freed while still being * journaled by a previous transaction may end up still * being dirty here, but we want to avoid writing back - * that buffer in the future now that the last use has - * been committed. That's not only a performance gain, - * it also stops aliasing problems if the buffer is left - * behind for writeback and gets reallocated for another + * that buffer in the future after the "add to orphan" + * operation been committed, That's not only a performance + * gain, it also stops aliasing problems if the buffer is + * left behind for writeback and gets reallocated for another * use in a different page. */ - if (buffer_freed(bh)) { + if (buffer_freed(bh) && !jh->b_next_transaction) { clear_buffer_freed(bh); clear_buffer_jbddirty(bh); } diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index a0512700542f..bfc70f57900f 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1727,6 +1727,21 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) if (!jh) goto zap_buffer_no_jh; + /* + * We cannot remove the buffer from checkpoint lists until the + * transaction adding inode to orphan list (let's call it T) + * is committed. Otherwise if the transaction changing the + * buffer would be cleaned from the journal before T is + * committed, a crash will cause that the correct contents of + * the buffer will be lost. On the other hand we have to + * clear the buffer dirty bit at latest at the moment when the + * transaction marking the buffer as freed in the filesystem + * structures is committed because from that moment on the + * buffer can be reallocated and used by a different page. + * Since the block hasn't been freed yet but the inode has + * already been added to orphan list, it is safe for us to add + * the buffer to BJ_Forget list of the newest transaction. + */ transaction = jh->b_transaction; if (transaction == NULL) { /* First case: not on any transaction. If it @@ -1783,16 +1798,15 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) } else if (transaction == journal->j_committing_transaction) { JBUFFER_TRACE(jh, "on committing transaction"); /* - * If it is committing, we simply cannot touch it. We - * can remove it's next_transaction pointer from the - * running transaction if that is set, but nothing - * else. */ + * The buffer is committing, we simply cannot touch + * it. So we just set j_next_transaction to the + * running transaction (if there is one) and mark + * buffer as freed so that commit code knows it should + * clear dirty bits when it is done with the buffer. + */ set_buffer_freed(bh); - if (jh->b_next_transaction) { - J_ASSERT(jh->b_next_transaction == - journal->j_running_transaction); - jh->b_next_transaction = NULL; - } + if (journal->j_running_transaction && buffer_jbddirty(bh)) + jh->b_next_transaction = journal->j_running_transaction; jbd2_journal_put_journal_head(jh); spin_unlock(&journal->j_list_lock); jbd_unlock_bh_state(bh); @@ -1969,7 +1983,7 @@ void jbd2_journal_file_buffer(struct journal_head *jh, */ void __jbd2_journal_refile_buffer(struct journal_head *jh) { - int was_dirty; + int was_dirty, jlist; struct buffer_head *bh = jh2bh(jh); J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); @@ -1991,8 +2005,13 @@ void __jbd2_journal_refile_buffer(struct journal_head *jh) __jbd2_journal_temp_unlink_buffer(jh); jh->b_transaction = jh->b_next_transaction; jh->b_next_transaction = NULL; - __jbd2_journal_file_buffer(jh, jh->b_transaction, - jh->b_modified ? BJ_Metadata : BJ_Reserved); + if (buffer_freed(bh)) + jlist = BJ_Forget; + else if (jh->b_modified) + jlist = BJ_Metadata; + else + jlist = BJ_Reserved; + __jbd2_journal_file_buffer(jh, jh->b_transaction, jlist); J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING); if (was_dirty) -- cgit v1.2.3 From 23e2af3518facab6838d7aac1f46fbd7a5a290ce Mon Sep 17 00:00:00 2001 From: dingdinghua Date: Wed, 24 Feb 2010 12:11:20 -0500 Subject: jbd2: clean up an assertion in jbd2_journal_commit_transaction() commit_transaction has the same value as journal->j_running_transaction, so we can simplify the assert statement. Signed-off-by: dingdinghua Signed-off-by: "Theodore Ts'o" --- fs/jbd2/commit.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'fs/jbd2') diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 3ee211ed58f1..671da7fb7ffd 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -883,8 +883,7 @@ restart_loop: spin_unlock(&journal->j_list_lock); bh = jh2bh(jh); jbd_lock_bh_state(bh); - J_ASSERT_JH(jh, jh->b_transaction == commit_transaction || - jh->b_transaction == journal->j_running_transaction); + J_ASSERT_JH(jh, jh->b_transaction == commit_transaction); /* * If there is undo-protected committed data against -- cgit v1.2.3