diff options
Diffstat (limited to 'fs/jbd2/journal.c')
| -rw-r--r-- | fs/jbd2/journal.c | 90 |
1 files changed, 81 insertions, 9 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 62be7d294ec..e378cb38397 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -38,6 +38,10 @@ #include <linux/debugfs.h> #include <linux/seq_file.h> #include <linux/math64.h> +#include <linux/hash.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/jbd2.h> #include <asm/uaccess.h> #include <asm/page.h> @@ -293,6 +297,7 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, unsigned int new_offset; struct buffer_head *bh_in = jh2bh(jh_in); struct jbd2_buffer_trigger_type *triggers; + journal_t *journal = transaction->t_journal; /* * The buffer really shouldn't be locked: only the current committing @@ -306,6 +311,11 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); + /* keep subsequent assertions sane */ + new_bh->b_state = 0; + init_buffer(new_bh, NULL, NULL); + atomic_set(&new_bh->b_count, 1); + new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */ /* * If a new transaction has already done a buffer copy-out, then @@ -384,14 +394,6 @@ repeat: kunmap_atomic(mapped_data, KM_USER0); } - /* keep subsequent assertions sane */ - new_bh->b_state = 0; - init_buffer(new_bh, NULL, NULL); - atomic_set(&new_bh->b_count, 1); - jbd_unlock_bh_state(bh_in); - - new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */ - set_bh_page(new_bh, new_page, new_offset); new_jh->b_transaction = NULL; new_bh->b_size = jh2bh(jh_in)->b_size; @@ -408,7 +410,11 @@ repeat: * copying is moved to the transaction's shadow queue. */ JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); - jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); + spin_lock(&journal->j_list_lock); + __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); + spin_unlock(&journal->j_list_lock); + jbd_unlock_bh_state(bh_in); + JBUFFER_TRACE(new_jh, "file as BJ_IO"); jbd2_journal_file_buffer(new_jh, transaction, BJ_IO); @@ -2377,6 +2383,72 @@ static void __exit journal_exit(void) jbd2_journal_destroy_caches(); } +/* + * jbd2_dev_to_name is a utility function used by the jbd2 and ext4 + * tracing infrastructure to map a dev_t to a device name. + * + * The caller should use rcu_read_lock() in order to make sure the + * device name stays valid until its done with it. We use + * rcu_read_lock() as well to make sure we're safe in case the caller + * gets sloppy, and because rcu_read_lock() is cheap and can be safely + * nested. + */ +struct devname_cache { + struct rcu_head rcu; + dev_t device; + char devname[BDEVNAME_SIZE]; +}; +#define CACHE_SIZE_BITS 6 +static struct devname_cache *devcache[1 << CACHE_SIZE_BITS]; +static DEFINE_SPINLOCK(devname_cache_lock); + +static void free_devcache(struct rcu_head *rcu) +{ + kfree(rcu); +} + +const char *jbd2_dev_to_name(dev_t device) +{ + int i = hash_32(device, CACHE_SIZE_BITS); + char *ret; + struct block_device *bd; + static struct devname_cache *new_dev; + + rcu_read_lock(); + if (devcache[i] && devcache[i]->device == device) { + ret = devcache[i]->devname; + rcu_read_unlock(); + return ret; + } + rcu_read_unlock(); + + new_dev = kmalloc(sizeof(struct devname_cache), GFP_KERNEL); + if (!new_dev) + return "NODEV-ALLOCFAILURE"; /* Something non-NULL */ + spin_lock(&devname_cache_lock); + if (devcache[i]) { + if (devcache[i]->device == device) { + kfree(new_dev); + ret = devcache[i]->devname; + spin_unlock(&devname_cache_lock); + return ret; + } + call_rcu(&devcache[i]->rcu, free_devcache); + } + devcache[i] = new_dev; + devcache[i]->device = device; + bd = bdget(device); + if (bd) { + bdevname(bd, devcache[i]->devname); + bdput(bd); + } else + __bdevname(device, devcache[i]->devname); + ret = devcache[i]->devname; + spin_unlock(&devname_cache_lock); + return ret; +} +EXPORT_SYMBOL(jbd2_dev_to_name); + MODULE_LICENSE("GPL"); module_init(journal_init); module_exit(journal_exit); |