diff options
Diffstat (limited to 'fs/jbd/transaction.c')
| -rw-r--r-- | fs/jbd/transaction.c | 104 |
1 files changed, 68 insertions, 36 deletions
diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c index 7fce94b04bc..1695ba8334a 100644 --- a/fs/jbd/transaction.c +++ b/fs/jbd/transaction.c @@ -26,7 +26,6 @@ #include <linux/mm.h> #include <linux/highmem.h> #include <linux/hrtimer.h> -#include <linux/backing-dev.h> static void __journal_temp_unlink_buffer(struct journal_head *jh); @@ -100,10 +99,11 @@ static int start_this_handle(journal_t *journal, handle_t *handle) alloc_transaction: if (!journal->j_running_transaction) { - new_transaction = kzalloc(sizeof(*new_transaction), GFP_NOFS); + new_transaction = kzalloc(sizeof(*new_transaction), + GFP_NOFS|__GFP_NOFAIL); if (!new_transaction) { - congestion_wait(BLK_RW_ASYNC, HZ/50); - goto alloc_transaction; + ret = -ENOMEM; + goto out; } } @@ -245,7 +245,6 @@ static handle_t *new_handle(int nblocks) handle_t *handle = jbd_alloc_handle(GFP_NOFS); if (!handle) return NULL; - memset(handle, 0, sizeof(*handle)); handle->h_buffer_credits = nblocks; handle->h_ref = 1; @@ -676,7 +675,7 @@ repeat: jbd_alloc(jh2bh(jh)->b_size, GFP_NOFS); if (!frozen_buffer) { - printk(KERN_EMERG + printk(KERN_ERR "%s: OOM for frozen_buffer\n", __func__); JBUFFER_TRACE(jh, "oom!"); @@ -718,9 +717,9 @@ done: "Possible IO failure.\n"); page = jh2bh(jh)->b_page; offset = offset_in_page(jh2bh(jh)->b_data); - source = kmap_atomic(page, KM_USER0); + source = kmap_atomic(page); memcpy(jh->b_frozen_data, source+offset, jh2bh(jh)->b_size); - kunmap_atomic(source, KM_USER0); + kunmap_atomic(source); } jbd_unlock_bh_state(bh); @@ -899,7 +898,7 @@ repeat: if (!jh->b_committed_data) { committed_data = jbd_alloc(jh2bh(jh)->b_size, GFP_NOFS); if (!committed_data) { - printk(KERN_EMERG "%s: No memory for committed data\n", + printk(KERN_ERR "%s: No memory for committed data\n", __func__); err = -ENOMEM; goto out; @@ -1259,7 +1258,7 @@ int journal_forget (handle_t *handle, struct buffer_head *bh) goto not_jbd; } - /* keep track of wether or not this transaction modified us */ + /* keep track of whether or not this transaction modified us */ was_modified = jh->b_modified; /* @@ -1433,8 +1432,6 @@ int journal_stop(handle_t *handle) } } - if (handle->h_sync) - transaction->t_synchronous_commit = 1; current->journal_info = NULL; spin_lock(&journal->j_state_lock); spin_lock(&transaction->t_handle_lock); @@ -1845,15 +1842,16 @@ static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction) * We're outside-transaction here. Either or both of j_running_transaction * and j_committing_transaction may be NULL. */ -static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) +static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh, + int partial_page) { transaction_t *transaction; struct journal_head *jh; int may_free = 1; - int ret; BUFFER_TRACE(bh, "entry"); +retry: /* * It is safe to proceed here without the j_list_lock because the * buffers cannot be stolen by try_to_free_buffers as long as we are @@ -1881,10 +1879,18 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) * 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. + * block 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. + * + * Also we have to clear buffer_mapped flag of a truncated buffer + * because the buffer_head may be attached to the page straddling + * i_size (can happen only when blocksize < pagesize) and thus the + * buffer_head can be reused when the file is extended again. So we end + * up keeping around invalidated buffers attached to transactions' + * BJ_Forget list just to stop checkpointing code from cleaning up + * the transaction this buffer was modified in. */ transaction = jh->b_transaction; if (transaction == NULL) { @@ -1911,13 +1917,9 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) * committed, the buffer won't be needed any * longer. */ JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget"); - ret = __dispose_buffer(jh, + may_free = __dispose_buffer(jh, journal->j_running_transaction); - journal_put_journal_head(jh); - spin_unlock(&journal->j_list_lock); - jbd_unlock_bh_state(bh); - spin_unlock(&journal->j_state_lock); - return ret; + goto zap_buffer; } else { /* There is no currently-running transaction. So the * orphan record which we wrote for this file must have @@ -1925,13 +1927,9 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) * the committing transaction, if it exists. */ if (journal->j_committing_transaction) { JBUFFER_TRACE(jh, "give to committing trans"); - ret = __dispose_buffer(jh, + may_free = __dispose_buffer(jh, journal->j_committing_transaction); - journal_put_journal_head(jh); - spin_unlock(&journal->j_list_lock); - jbd_unlock_bh_state(bh); - spin_unlock(&journal->j_state_lock); - return ret; + goto zap_buffer; } else { /* The orphan record's transaction has * committed. We can cleanse this buffer */ @@ -1952,10 +1950,26 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) } /* * 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. + * it. If the page is straddling i_size we have to wait + * for commit and try again. + */ + if (partial_page) { + tid_t tid = journal->j_committing_transaction->t_tid; + + journal_put_journal_head(jh); + spin_unlock(&journal->j_list_lock); + jbd_unlock_bh_state(bh); + spin_unlock(&journal->j_state_lock); + unlock_buffer(bh); + log_wait_commit(journal, tid); + lock_buffer(bh); + goto retry; + } + /* + * OK, buffer won't be reachable after truncate. 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 (journal->j_running_transaction && buffer_jbddirty(bh)) @@ -1978,6 +1992,14 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) } zap_buffer: + /* + * This is tricky. Although the buffer is truncated, it may be reused + * if blocksize < pagesize and it is attached to the page straddling + * EOF. Since the buffer might have been added to BJ_Forget list of the + * running transaction, journal_get_write_access() won't clear + * b_modified and credit accounting gets confused. So clear b_modified + * here. */ + jh->b_modified = 0; journal_put_journal_head(jh); zap_buffer_no_jh: spin_unlock(&journal->j_list_lock); @@ -1997,16 +2019,20 @@ zap_buffer_unlocked: * void journal_invalidatepage() - invalidate a journal page * @journal: journal to use for flush * @page: page to flush - * @offset: length of page to invalidate. + * @offset: offset of the range to invalidate + * @length: length of the range to invalidate * - * Reap page buffers containing data after offset in page. + * Reap page buffers containing data in specified range in page. */ void journal_invalidatepage(journal_t *journal, struct page *page, - unsigned long offset) + unsigned int offset, + unsigned int length) { struct buffer_head *head, *bh, *next; + unsigned int stop = offset + length; unsigned int curr_off = 0; + int partial_page = (offset || length < PAGE_CACHE_SIZE); int may_free = 1; if (!PageLocked(page)) @@ -2014,6 +2040,8 @@ void journal_invalidatepage(journal_t *journal, if (!page_has_buffers(page)) return; + BUG_ON(stop > PAGE_CACHE_SIZE || stop < length); + /* We will potentially be playing with lists other than just the * data lists (especially for journaled data mode), so be * cautious in our locking. */ @@ -2023,10 +2051,14 @@ void journal_invalidatepage(journal_t *journal, unsigned int next_off = curr_off + bh->b_size; next = bh->b_this_page; + if (next_off > stop) + return; + if (offset <= curr_off) { /* This block is wholly outside the truncation point */ lock_buffer(bh); - may_free &= journal_unmap_buffer(journal, bh); + may_free &= journal_unmap_buffer(journal, bh, + partial_page); unlock_buffer(bh); } curr_off = next_off; @@ -2034,7 +2066,7 @@ void journal_invalidatepage(journal_t *journal, } while (bh != head); - if (!offset) { + if (!partial_page) { if (may_free && try_to_free_buffers(page)) J_ASSERT(!page_has_buffers(page)); } |