diff options
Diffstat (limited to 'fs/buffer.c')
| -rw-r--r-- | fs/buffer.c | 66 |
1 files changed, 38 insertions, 28 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index 561e63a1496..6cbfceabd95 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -40,6 +40,7 @@ #include <linux/cpu.h> #include <linux/bitops.h> #include <linux/mpage.h> +#include <linux/bit_spinlock.h> static int fsync_buffers_list(spinlock_t *lock, struct list_head *list); static void invalidate_bh_lrus(void); @@ -513,8 +514,8 @@ static void free_more_memory(void) */ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) { - static DEFINE_SPINLOCK(page_uptodate_lock); unsigned long flags; + struct buffer_head *first; struct buffer_head *tmp; struct page *page; int page_uptodate = 1; @@ -536,7 +537,9 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) * two buffer heads end IO at almost the same time and both * decide that the page is now completely done. */ - spin_lock_irqsave(&page_uptodate_lock, flags); + first = page_buffers(page); + local_irq_save(flags); + bit_spin_lock(BH_Uptodate_Lock, &first->b_state); clear_buffer_async_read(bh); unlock_buffer(bh); tmp = bh; @@ -549,7 +552,8 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) } tmp = tmp->b_this_page; } while (tmp != bh); - spin_unlock_irqrestore(&page_uptodate_lock, flags); + bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); + local_irq_restore(flags); /* * If none of the buffers had errors and they are all @@ -561,7 +565,8 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) return; still_busy: - spin_unlock_irqrestore(&page_uptodate_lock, flags); + bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); + local_irq_restore(flags); return; } @@ -572,8 +577,8 @@ still_busy: void end_buffer_async_write(struct buffer_head *bh, int uptodate) { char b[BDEVNAME_SIZE]; - static DEFINE_SPINLOCK(page_uptodate_lock); unsigned long flags; + struct buffer_head *first; struct buffer_head *tmp; struct page *page; @@ -594,7 +599,10 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate) SetPageError(page); } - spin_lock_irqsave(&page_uptodate_lock, flags); + first = page_buffers(page); + local_irq_save(flags); + bit_spin_lock(BH_Uptodate_Lock, &first->b_state); + clear_buffer_async_write(bh); unlock_buffer(bh); tmp = bh->b_this_page; @@ -605,12 +613,14 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate) } tmp = tmp->b_this_page; } - spin_unlock_irqrestore(&page_uptodate_lock, flags); + bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); + local_irq_restore(flags); end_page_writeback(page); return; still_busy: - spin_unlock_irqrestore(&page_uptodate_lock, flags); + bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); + local_irq_restore(flags); return; } @@ -908,8 +918,7 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list) * contents - it is a noop if I/O is still in * flight on potentially older contents. */ - wait_on_buffer(bh); - ll_rw_block(WRITE, 1, &bh); + ll_rw_block(SWRITE, 1, &bh); brelse(bh); spin_lock(lock); } @@ -2784,21 +2793,22 @@ int submit_bh(int rw, struct buffer_head * bh) /** * ll_rw_block: low-level access to block devices (DEPRECATED) - * @rw: whether to %READ or %WRITE or maybe %READA (readahead) + * @rw: whether to %READ or %WRITE or %SWRITE or maybe %READA (readahead) * @nr: number of &struct buffer_heads in the array * @bhs: array of pointers to &struct buffer_head * - * ll_rw_block() takes an array of pointers to &struct buffer_heads, - * and requests an I/O operation on them, either a %READ or a %WRITE. - * The third %READA option is described in the documentation for - * generic_make_request() which ll_rw_block() calls. + * ll_rw_block() takes an array of pointers to &struct buffer_heads, and + * requests an I/O operation on them, either a %READ or a %WRITE. The third + * %SWRITE is like %WRITE only we make sure that the *current* data in buffers + * are sent to disk. The fourth %READA option is described in the documentation + * for generic_make_request() which ll_rw_block() calls. * * This function drops any buffer that it cannot get a lock on (with the - * BH_Lock state bit), any buffer that appears to be clean when doing a - * write request, and any buffer that appears to be up-to-date when doing - * read request. Further it marks as clean buffers that are processed for - * writing (the buffer cache won't assume that they are actually clean until - * the buffer gets unlocked). + * BH_Lock state bit) unless SWRITE is required, any buffer that appears to be + * clean when doing a write request, and any buffer that appears to be + * up-to-date when doing read request. Further it marks as clean buffers that + * are processed for writing (the buffer cache won't assume that they are + * actually clean until the buffer gets unlocked). * * ll_rw_block sets b_end_io to simple completion handler that marks * the buffer up-to-date (if approriate), unlocks the buffer and wakes @@ -2814,11 +2824,13 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[]) for (i = 0; i < nr; i++) { struct buffer_head *bh = bhs[i]; - if (test_set_buffer_locked(bh)) + if (rw == SWRITE) + lock_buffer(bh); + else if (test_set_buffer_locked(bh)) continue; get_bh(bh); - if (rw == WRITE) { + if (rw == WRITE || rw == SWRITE) { if (test_clear_buffer_dirty(bh)) { bh->b_end_io = end_buffer_write_sync; submit_bh(WRITE, bh); @@ -3037,10 +3049,9 @@ struct buffer_head *alloc_buffer_head(unsigned int __nocast gfp_flags) { struct buffer_head *ret = kmem_cache_alloc(bh_cachep, gfp_flags); if (ret) { - preempt_disable(); - __get_cpu_var(bh_accounting).nr++; + get_cpu_var(bh_accounting).nr++; recalc_bh_state(); - preempt_enable(); + put_cpu_var(bh_accounting); } return ret; } @@ -3050,10 +3061,9 @@ void free_buffer_head(struct buffer_head *bh) { BUG_ON(!list_empty(&bh->b_assoc_buffers)); kmem_cache_free(bh_cachep, bh); - preempt_disable(); - __get_cpu_var(bh_accounting).nr--; + get_cpu_var(bh_accounting).nr--; recalc_bh_state(); - preempt_enable(); + put_cpu_var(bh_accounting); } EXPORT_SYMBOL(free_buffer_head); |