diff options
| -rw-r--r-- | fs/buffer.c | 50 | ||||
| -rw-r--r-- | include/linux/sched.h | 7 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 6 |
3 files changed, 61 insertions, 2 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index 4cc679d5bf58..11f93532d012 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -955,10 +955,20 @@ grow_dev_page(struct block_device *bdev, sector_t block, end_block = init_page_buffers(page, bdev, (sector_t)index << sizebits, size); +#ifdef CONFIG_DEBUG_AID_FOR_SYZBOT + current->getblk_executed |= 0x01; +#endif goto done; } - if (!try_to_free_buffers(page)) + if (!try_to_free_buffers(page)) { +#ifdef CONFIG_DEBUG_AID_FOR_SYZBOT + current->getblk_executed |= 0x02; +#endif goto failed; + } +#ifdef CONFIG_DEBUG_AID_FOR_SYZBOT + current->getblk_executed |= 0x04; +#endif } /* @@ -978,6 +988,9 @@ grow_dev_page(struct block_device *bdev, sector_t block, spin_unlock(&inode->i_mapping->private_lock); done: ret = (block < end_block) ? 1 : -ENXIO; +#ifdef CONFIG_DEBUG_AID_FOR_SYZBOT + current->getblk_executed |= 0x08; +#endif failed: unlock_page(page); put_page(page); @@ -1033,6 +1046,12 @@ __getblk_slow(struct block_device *bdev, sector_t block, return NULL; } +#ifdef CONFIG_DEBUG_AID_FOR_SYZBOT + current->getblk_stamp = jiffies; + current->getblk_executed = 0; + current->getblk_bh_count = 0; + current->getblk_bh_state = 0; +#endif for (;;) { struct buffer_head *bh; int ret; @@ -1044,6 +1063,18 @@ __getblk_slow(struct block_device *bdev, sector_t block, ret = grow_buffers(bdev, block, size, gfp); if (ret < 0) return NULL; + +#ifdef CONFIG_DEBUG_AID_FOR_SYZBOT + if (!time_after(jiffies, current->getblk_stamp + 3 * HZ)) + continue; + printk(KERN_ERR "%s(%u): getblk(): executed=%x bh_count=%d bh_state=%lx\n", + current->comm, current->pid, current->getblk_executed, + current->getblk_bh_count, current->getblk_bh_state); + current->getblk_executed = 0; + current->getblk_bh_count = 0; + current->getblk_bh_state = 0; + current->getblk_stamp = jiffies; +#endif } } @@ -3216,6 +3247,11 @@ EXPORT_SYMBOL(sync_dirty_buffer); */ static inline int buffer_busy(struct buffer_head *bh) { +#ifdef CONFIG_DEBUG_AID_FOR_SYZBOT + current->getblk_executed |= 0x80; + current->getblk_bh_count = atomic_read(&bh->b_count); + current->getblk_bh_state = bh->b_state; +#endif return atomic_read(&bh->b_count) | (bh->b_state & ((1 << BH_Dirty) | (1 << BH_Lock))); } @@ -3254,11 +3290,18 @@ int try_to_free_buffers(struct page *page) int ret = 0; BUG_ON(!PageLocked(page)); - if (PageWriteback(page)) + if (PageWriteback(page)) { +#ifdef CONFIG_DEBUG_AID_FOR_SYZBOT + current->getblk_executed |= 0x10; +#endif return 0; + } if (mapping == NULL) { /* can this still happen? */ ret = drop_buffers(page, &buffers_to_free); +#ifdef CONFIG_DEBUG_AID_FOR_SYZBOT + current->getblk_executed |= 0x20; +#endif goto out; } @@ -3282,6 +3325,9 @@ int try_to_free_buffers(struct page *page) if (ret) cancel_dirty_page(page); spin_unlock(&mapping->private_lock); +#ifdef CONFIG_DEBUG_AID_FOR_SYZBOT + current->getblk_executed |= 0x40; +#endif out: if (buffers_to_free) { struct buffer_head *bh = buffers_to_free; diff --git a/include/linux/sched.h b/include/linux/sched.h index 977cb57d7bc9..0770678dcc42 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1192,6 +1192,13 @@ struct task_struct { void *security; #endif +#ifdef CONFIG_DEBUG_AID_FOR_SYZBOT + unsigned long getblk_stamp; + unsigned int getblk_executed; + unsigned int getblk_bh_count; + unsigned long getblk_bh_state; +#endif + /* * New fields for task_struct should be added above here, so that * they are included in the randomized portion of task_struct. diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 3589765141a8..aeb630972418 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2031,6 +2031,12 @@ config IO_STRICT_DEVMEM If in doubt, say Y. +config DEBUG_AID_FOR_SYZBOT + bool "Additional debug code for syzbot" + default n + help + This option is intended for testing by syzbot. + source "arch/$(SRCARCH)/Kconfig.debug" endmenu # Kernel hacking |