| Message ID | 20240706075228.2350978-3-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] block: add a bvec_phys helper | expand |
On 7/6/2024 12:52 AM, Christoph Hellwig wrote: > Work on a single address to simplify the logic, and prepare the callers > from using better helpers. > > Signed-off-by: Christoph Hellwig<hch@lst.de> > --- > block/blk-merge.c | 25 +++++++++++-------------- > 1 file changed, 11 insertions(+), 14 deletions(-) > > diff --git a/block/blk-merge.c b/block/blk-merge.c > index cff20bcc0252a7..e41ea331809936 100644 > --- a/block/blk-merge.c > +++ b/block/blk-merge.c > @@ -209,23 +209,22 @@ static inline unsigned get_max_io_size(struct bio *bio, > /** > * get_max_segment_size() - maximum number of bytes to add as a single segment > * @lim: Request queue limits. > - * @start_page: See below. > - * @offset: Offset from @start_page where to add a segment. > + * @paddr: address of the range to add > + * @max_len: maximum length available to add at @paddr > * > - * Returns the maximum number of bytes that can be added as a single segment. > + * Returns the maximum number of bytes of the range starting at @paddr that can > + * be added to a single segment. > */ > static inline unsigned get_max_segment_size(const struct queue_limits *lim, > - struct page *start_page, unsigned long offset) > + phys_addr_t paddr, unsigned int len) > { > - unsigned long mask = lim->seg_boundary_mask; > - > - offset = mask & (page_to_phys(start_page) + offset); > - > /* > * Prevent an overflow if mask = ULONG_MAX and offset = 0 by adding 1 > * after having calculated the minimum. > */ > - return min(mask - offset, (unsigned long)lim->max_segment_size - 1) + 1; > + return min_t(unsigned long, len, > + min(lim->seg_boundary_mask - (lim->seg_boundary_mask & paddr), > + (unsigned long)lim->max_segment_size - 1) + 1); > } > Looks good, is it possible to re-write last return min_t(..., ..., min(..., ...)) statement something like totally untested in [1] ? Irrespective of that, looks good. Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> -ck [1] static inline unsigned get_max_segment_size(const struct queue_limits *lim, phys_addr_t paddr, unsigned int paddr_len) { unsigned long paddr_max_seg_allowed_len; unsigned long paddr_seg_boundry; paddr_seg_boundry = lim->seg_boundary_mask - (lim->seg_boundary_mask & paddr); /* * Prevent an overflow if mask = ULONG_MAX and offset = 0 by adding 1 * after having calculated the minimum. */ paddr_max_seg_allowed_len = min(paddr_seg_boundry, (unsigned long)lim->max_segment_size - 1) + 1; return min_t(unsigned long, paddr_len, paddr_max_seg_allowed_len); }
On Sat, Jul 06, 2024 at 10:37:11AM +0000, Chaitanya Kulkarni wrote: > > - return min(mask - offset, (unsigned long)lim->max_segment_size - 1) + 1; > > + return min_t(unsigned long, len, > > + min(lim->seg_boundary_mask - (lim->seg_boundary_mask & paddr), > > + (unsigned long)lim->max_segment_size - 1) + 1); > > } > > > > Looks good, is it possible to re-write last > return min_t(..., ..., min(..., ...)) statement something like totally > untested in [1] ? > paddr_seg_boundry = > lim->seg_boundary_mask - (lim->seg_boundary_mask & paddr); > /* > * Prevent an overflow if mask = ULONG_MAX and offset = 0 by > adding 1 > * after having calculated the minimum. > */ > paddr_max_seg_allowed_len = min(paddr_seg_boundry, > (unsigned long)lim->max_segment_size - > 1) + 1; > return min_t(unsigned long, paddr_len, paddr_max_seg_allowed_len); > } What would be the point of that? It is way harder to read and longer. But except for that we probably could. > > ---end quoted text---
Hi Christoph, On Sat, Jul 6, 2024 at 9:52 AM Christoph Hellwig <hch@lst.de> wrote: > Work on a single address to simplify the logic, and prepare the callers > from using better helpers. > > Signed-off-by: Christoph Hellwig <hch@lst.de> Thanks for your patch, which is now commit 09595e0c9d654743 ("block: pass a phys_addr_t to get_max_segment_size") in block/for-next This is causing the following crash on landisk when starting a Debian userspace: Run /sbin/init as init process process '/sbin/init' started with executable stack ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at block/blk-merge.c:607 __blk_rq_map_sg+0x74/0x240 Modules linked in: CPU: 0 PID: 1 Comm: init Not tainted 6.10.0-rc3-landisk-00178-g09595e0c9d65 #228 PC is at __blk_rq_map_sg+0x74/0x240 PR is at __blk_rq_map_sg+0x1ee/0x240 PC : 8c1d58f8 SP : 8c825bec SR : 40008100 TEA : 295ce8b0 R0 : 00000002 R1 : 00000002 R2 : fffffffe R3 : 8c1fc2a0 R4 : 8c825c0c R5 : 8c825c00 R6 : 00000000 R7 : 00000001 R8 : 8cb2c040 R9 : 8c825c50 R10 : 00000000 R11 : 00000003 R12 : 00000000 R13 : 8cb2c158 R14 : 00000000 MACH: 0000565d MACL: 00000000 GBR : 00000000 PR : 8c1d5a72 Call trace: [<8c26a1c8>] scsi_alloc_sgtables+0xb8/0x1ac [<8c2736aa>] sd_init_command+0x2a2/0x70a [<8c03a910>] irqd_irq_disabled.isra.0+0x0/0xc [<8c26b296>] scsi_queue_rq+0x512/0x634 [<8c1db0d0>] blk_mq_dispatch_rq_list+0x1c8/0x358 [<8c1dac28>] blk_mq_get_driver_tag+0x0/0x14 [<8c20ef8e>] sbitmap_get+0x5a/0x78 [<8c1dab01>] blk_mq_dequeue_from_ctx+0xd/0x64 [<8c1deaf6>] __blk_mq_sched_dispatch_requests+0x24a/0x38c [<8c1dec9a>] blk_mq_sched_dispatch_requests+0x22/0x50 [<8c1d86fa>] blk_rq_is_passthrough.isra.0+0x0/0xc [<8c1dec78>] blk_mq_sched_dispatch_requests+0x0/0x50 [<8c1de8ac>] __blk_mq_sched_dispatch_requests+0x0/0x38c [<8c1da158>] blk_mq_run_hw_queue+0xc8/0xf8 [<8c1db3d4>] blk_mq_flush_plug_list+0x174/0x28c [<8c1d86fa>] blk_rq_is_passthrough.isra.0+0x0/0xc [<8c1d1e32>] __blk_flush_plug+0x3e/0xd8 [<8c0025d8>] arch_local_irq_restore+0x0/0x24 [<8c071838>] arch_local_irq_save+0x0/0x24 [<8c071a0c>] readahead_folio+0x0/0x60 [<8c1d1ee4>] blk_finish_plug+0x18/0x30 [<8c0025d8>] arch_local_irq_restore+0x0/0x24 [<8c071838>] arch_local_irq_save+0x0/0x24 [<8c071a0c>] readahead_folio+0x0/0x60 [<8c071ada>] read_pages+0x4c/0x106 [<8c071c26>] page_cache_ra_unbounded+0x92/0x14c [<8c06c37c>] filemap_fault+0x2c8/0x43c [<8c087d30>] __do_fault+0x1c/0x6c [<8c08b0cc>] handle_mm_fault+0x588/0x780 [<8c00cb14>] do_page_fault+0x10c/0x1a0 [<8c006108>] ret_from_exception+0x0/0xc [<8c006108>] ret_from_exception+0x0/0xc [<8c006108>] ret_from_exception+0x0/0xc ---[ end trace 0000000000000000 ]--- ------------[ cut here ]------------ kernel BUG at drivers/scsi/scsi_lib.c:1160! Kernel BUG: 003e [#1] Modules linked in: CPU: 0 PID: 1 Comm: init Tainted: G W 6.10.0-rc3-landisk-00178-g09595e0c9d65 #228 PC is at scsi_alloc_sgtables+0x144/0x1ac PR is at scsi_alloc_sgtables+0xb8/0x1ac PC : 8c26a254 SP : 8c825c50 SR : 40008100 TEA : 295ce8b0 R0 : 00000003 R1 : 00000002 R2 : 8cb2c180 R3 : 000000bc R4 : 8c825c0c R5 : 8c825c00 R6 : 00000000 R7 : 00000000 R8 : 8cb2c09c R9 : 8cb4cafc R10 : 8c51b12c R11 : 8cb2c118 R12 : 8cb2c000 R13 : 00000000 R14 : 00000003 MACH: 0000565d MACL: 00000000 GBR : 00000000 PR : 8c26a1c8 Call trace: [<8c2736aa>] sd_init_command+0x2a2/0x70a [<8c03a910>] irqd_irq_disabled.isra.0+0x0/0xc [<8c26b296>] scsi_queue_rq+0x512/0x634 [<8c1db0d0>] blk_mq_dispatch_rq_list+0x1c8/0x358 [<8c1dac28>] blk_mq_get_driver_tag+0x0/0x14 [<8c20ef8e>] sbitmap_get+0x5a/0x78 [<8c1dab01>] blk_mq_dequeue_from_ctx+0xd/0x64 [<8c1deaf6>] __blk_mq_sched_dispatch_requests+0x24a/0x38c [<8c1dec9a>] blk_mq_sched_dispatch_requests+0x22/0x50 [<8c1d86fa>] blk_rq_is_passthrough.isra.0+0x0/0xc [<8c1dec78>] blk_mq_sched_dispatch_requests+0x0/0x50 [<8c1de8ac>] __blk_mq_sched_dispatch_requests+0x0/0x38c [<8c1da158>] blk_mq_run_hw_queue+0xc8/0xf8 [<8c1db3d4>] blk_mq_flush_plug_list+0x174/0x28c [<8c1d86fa>] blk_rq_is_passthrough.isra.0+0x0/0xc [<8c1d1e32>] __blk_flush_plug+0x3e/0xd8 [<8c0025d8>] arch_local_irq_restore+0x0/0x24 [<8c071838>] arch_local_irq_save+0x0/0x24 [<8c071a0c>] readahead_folio+0x0/0x60 [<8c1d1ee4>] blk_finish_plug+0x18/0x30 [<8c0025d8>] arch_local_irq_restore+0x0/0x24 [<8c071838>] arch_local_irq_save+0x0/0x24 [<8c071a0c>] readahead_folio+0x0/0x60 [<8c071ada>] read_pages+0x4c/0x106 [<8c071c26>] page_cache_ra_unbounded+0x92/0x14c [<8c06c37c>] filemap_fault+0x2c8/0x43c [<8c087d30>] __do_fault+0x1c/0x6c [<8c08b0cc>] handle_mm_fault+0x588/0x780 [<8c00cb14>] do_page_fault+0x10c/0x1a0 [<8c006108>] ret_from_exception+0x0/0xc [<8c006108>] ret_from_exception+0x0/0xc [<8c006108>] ret_from_exception+0x0/0xc Process: init (pid: 1, stack limit = (ptrval)) Stack: (0x8c825c50 to 0x8c826000) 5c40: 8cb2c180 c4b8bd37 8c2736aa 8cb2c000 5c60: 00000001 00000000 8c93e800 00000088 0008d350 8cb2c09c 8cb25200 8c03a910 5c80: 8c807840 8cb4c800 8cb28600 00000088 00080700 00000000 00000020 8c26b296 5ca0: 8cb2c118 8cb2c11c 8cb4c800 8c93e800 8cb2c000 8cb4c800 8cb2c09c 8cb2c13c 5cc0: 8c93e800 00000003 8cb28014 8cb4cafc 8cb29000 8c825d20 8cb4c8fc 8c1db0d0 5ce0: 00000000 8c1dac28 8cb2c034 8cb25100 8cb2c000 8cb25100 8c825d5c 00000000 5d00: 8c20ef8e 8c825d20 00000000 00000000 ffffffff 00000000 00000000 8cb29000 5d20: 8cb2c000 8c1dab01 c4b8bd37 8c1deaf6 00000000 00000002 8cb28c00 00000000 5d40: 00000001 8c825d5c 8cb25100 00000000 fffede60 8c825d54 8c825d54 8c825d5c 5d60: 8c825d5c 8cb2c000 8cb29000 c4b8bd37 8c1dec9a 00000000 8c1d86fa 8cb25140 5d80: 8c1dec78 00000000 8c1de8ac 8cb25100 8c1da158 8cb25100 8c93e8a0 8c1db3d4 5da0: 8c1d86fa 8cb25140 8cb2c034 8cb25100 8c825dd0 8c825e2c 00000000 8ff7666c 5dc0: 00000000 8c825dcc 8cb25100 00000000 8c825dd0 8c825dd0 c4b8bd37 8c1d1e32 5de0: 8c0025d8 8c071838 8c071a0c 00000000 8c51b12c 8c825e44 8c825e2c 00000001 5e00: 8c825e10 c4b8bd37 8c1d1ee4 8c0025d8 8c071838 8c071a0c 8c51b12c 00112cca 5e20: 00000000 8c825eac 8c071ada 00000000 00000000 ce7eb754 00000002 00000001 5e40: 00110100 8c825e44 8c825e44 c4b8bd37 8c071c26 00000011 8c825eac 8cb95cec 5e60: 0000002a 00112cca 8cb95ce0 8ff8cb20 0000003a 00000011 00402100 00000008 5e80: 8c06c37c 0000003a 8cb95ce0 8cb95ce0 8ca56280 8c825f18 8ca56280 8ca562c0 5ea0: 00000000 8ca56280 8cb95c0c 8ca56280 8cb95ce0 8ca562c0 0000003b 00000000 5ec0: 00000000 00000000 00000000 c4b8bd37 8c087d30 01000000 00000000 00000d73 5ee0: 295ce8b0 8cbc81f8 8c825f18 8cbc81f8 8c08b0cc 00000001 8ff8c900 8cbc81f8 5f00: ffffffff 8c931784 295ce000 00000255 8c825fa4 00000040 8cbc81f8 00100cca 5f20: 0000003a 295ce000 295ce8b0 00000a55 8cc06294 8cc06294 00000000 8ff8c900 5f40: 00000000 00000000 8c9317ac 00000000 c4b8bd37 8c00cb14 01000000 8c825fe4 5f60: 295ce8b0 00000255 00000001 8c825fa4 00000001 00000812 0000003a 8c931780 5f80: 00000001 8c006108 7bb436b4 295d8de4 29581000 295ce8b0 8c006108 8c006108 5fa0: 00000001 00000007 00000000 0000f686 000000ea 295ce8b0 00000000 00000000 5fc0: 295ce8b0 295cf000 7bb43668 29581a58 295ce8b0 29581000 295d8de4 7bb436b4 5fe0: 7bb43650 2956c3d8 2955cd1a 00008000 00000000 0000002c 00000030 ffffffff ---[ end trace 0000000000000000 ]--- ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at kernel/exit.c:823 do_exit+0x68/0x704 Modules linked in: CPU: 0 PID: 1 Comm: init Tainted: G D W 6.10.0-rc3-landisk-00178-g09595e0c9d65 #228 PC is at do_exit+0x68/0x704 PR is at do_exit+0x5c/0x704 PC : 8c011a2c SP : 8c825b5c SR : 40008100 TEA : 295ce8b0 R0 : 00000040 R1 : 8c825e2c R2 : 40008100 R3 : 00000000 R4 : 00000000 R5 : ffd0b128 R6 : 00000000 R7 : 00000001 R8 : 8c822000 R9 : 8c010da4 R10 : 8c8222fc R11 : 8c010d94 R12 : 0000000b R13 : 8c3b4d70 R14 : 00000003 MACH: 00000244 MACL: 0000afa8 GBR : 00000000 PR : 8c011a20 Call trace: [<8c035e60>] vprintk_emit+0xc0/0x13c [<8c3b4d70>] _printk+0x0/0x48 [<8c0121a2>] make_task_dead+0xda/0x130 [<8c3b4d70>] _printk+0x0/0x48 [<8c003ede>] die+0xde/0x14c [<8c1fce6c>] bust_spinlocks+0x0/0x38 [<8c0025d8>] arch_local_irq_restore+0x0/0x24 [<8c0040f8>] bug_trap_handler+0x8c/0xc8 [<8c26a254>] scsi_alloc_sgtables+0x144/0x1ac [<8c0061be>] debug_trap+0xe/0x18 [<8c00406c>] bug_trap_handler+0x0/0xc8 [<8c26a254>] scsi_alloc_sgtables+0x144/0x1ac [<8c26a1c8>] scsi_alloc_sgtables+0xb8/0x1ac [<8c2736aa>] sd_init_command+0x2a2/0x70a [<8c03a910>] irqd_irq_disabled.isra.0+0x0/0xc [<8c26b296>] scsi_queue_rq+0x512/0x634 [<8c1db0d0>] blk_mq_dispatch_rq_list+0x1c8/0x358 [<8c1dac28>] blk_mq_get_driver_tag+0x0/0x14 [<8c20ef8e>] sbitmap_get+0x5a/0x78 [<8c1dab01>] blk_mq_dequeue_from_ctx+0xd/0x64 [<8c1deaf6>] __blk_mq_sched_dispatch_requests+0x24a/0x38c [<8c1dec9a>] blk_mq_sched_dispatch_requests+0x22/0x50 [<8c1d86fa>] blk_rq_is_passthrough.isra.0+0x0/0xc [<8c1dec78>] blk_mq_sched_dispatch_requests+0x0/0x50 [<8c1de8ac>] __blk_mq_sched_dispatch_requests+0x0/0x38c [<8c1da158>] blk_mq_run_hw_queue+0xc8/0xf8 [<8c1db3d4>] blk_mq_flush_plug_list+0x174/0x28c [<8c1d86fa>] blk_rq_is_passthrough.isra.0+0x0/0xc [<8c1d1e32>] __blk_flush_plug+0x3e/0xd8 [<8c0025d8>] arch_local_irq_restore+0x0/0x24 [<8c071838>] arch_local_irq_save+0x0/0x24 [<8c071a0c>] readahead_folio+0x0/0x60 [<8c1d1ee4>] blk_finish_plug+0x18/0x30 [<8c0025d8>] arch_local_irq_restore+0x0/0x24 [<8c071838>] arch_local_irq_save+0x0/0x24 [<8c071a0c>] readahead_folio+0x0/0x60 [<8c071ada>] read_pages+0x4c/0x106 [<8c071c26>] page_cache_ra_unbounded+0x92/0x14c [<8c06c37c>] filemap_fault+0x2c8/0x43c [<8c087d30>] __do_fault+0x1c/0x6c [<8c08b0cc>] handle_mm_fault+0x588/0x780 [<8c00cb14>] do_page_fault+0x10c/0x1a0 [<8c006108>] ret_from_exception+0x0/0xc [<8c006108>] ret_from_exception+0x0/0xc [<8c006108>] ret_from_exception+0x0/0xc ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Rebooting in 10 seconds.. Other people seem to have run into similar issues https://lore.kernel.org/all/58a667c3-e884-4fa0-9855-3a73a1880260@nvidia.com/ > --- a/block/blk-merge.c > +++ b/block/blk-merge.c > @@ -209,23 +209,22 @@ static inline unsigned get_max_io_size(struct bio *bio, > /** > * get_max_segment_size() - maximum number of bytes to add as a single segment > * @lim: Request queue limits. > - * @start_page: See below. > - * @offset: Offset from @start_page where to add a segment. > + * @paddr: address of the range to add > + * @max_len: maximum length available to add at @paddr > * > - * Returns the maximum number of bytes that can be added as a single segment. > + * Returns the maximum number of bytes of the range starting at @paddr that can > + * be added to a single segment. > */ > static inline unsigned get_max_segment_size(const struct queue_limits *lim, > - struct page *start_page, unsigned long offset) > + phys_addr_t paddr, unsigned int len) > { > - unsigned long mask = lim->seg_boundary_mask; > - > - offset = mask & (page_to_phys(start_page) + offset); > - > /* > * Prevent an overflow if mask = ULONG_MAX and offset = 0 by adding 1 > * after having calculated the minimum. > */ > - return min(mask - offset, (unsigned long)lim->max_segment_size - 1) + 1; > + return min_t(unsigned long, len, > + min(lim->seg_boundary_mask - (lim->seg_boundary_mask & paddr), > + (unsigned long)lim->max_segment_size - 1) + 1); > } > > /** > @@ -258,9 +257,7 @@ static bool bvec_split_segs(const struct queue_limits *lim, > unsigned seg_size = 0; > > while (len && *nsegs < max_segs) { > - seg_size = get_max_segment_size(lim, bv->bv_page, > - bv->bv_offset + total_len); > - seg_size = min(seg_size, len); > + seg_size = get_max_segment_size(lim, bvec_phys(bv) + total_len, len); > > (*nsegs)++; > total_len += seg_size; > @@ -494,8 +491,8 @@ static unsigned blk_bvec_map_sg(struct request_queue *q, > > while (nbytes > 0) { > unsigned offset = bvec->bv_offset + total; > - unsigned len = min(get_max_segment_size(&q->limits, > - bvec->bv_page, offset), nbytes); > + unsigned len = get_max_segment_size(&q->limits, bvec_phys(bvec), > + nbytes); > struct page *page = bvec->bv_page; > > /* Gr{oetje,eeting}s, Geert
Hi Geert, the fix is queued up here: https://git.kernel.dk/cgit/linux-block/commit/?h=for-6.11/block&id=61353a63a22890f2c642232ae1ab4a2e02e6a27c and should be in linux-next. And next time I need to do a full retest after doing your suggested patch order change :)
Hi Christoph, On Wed, Jul 10, 2024 at 7:52 AM Christoph Hellwig <hch@lst.de> wrote: > the fix is queued up here: > > https://git.kernel.dk/cgit/linux-block/commit/?h=for-6.11/block&id=61353a63a22890f2c642232ae1ab4a2e02e6a27c Thanks, that fixed the issue! > and should be in linux-next. And next time I need to do a full > retest after doing your suggested patch order change :) Always run git diff and git range-diff against the original after a rebase ;-) Gr{oetje,eeting}s, Geert
diff --git a/block/blk-merge.c b/block/blk-merge.c index cff20bcc0252a7..e41ea331809936 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -209,23 +209,22 @@ static inline unsigned get_max_io_size(struct bio *bio, /** * get_max_segment_size() - maximum number of bytes to add as a single segment * @lim: Request queue limits. - * @start_page: See below. - * @offset: Offset from @start_page where to add a segment. + * @paddr: address of the range to add + * @max_len: maximum length available to add at @paddr * - * Returns the maximum number of bytes that can be added as a single segment. + * Returns the maximum number of bytes of the range starting at @paddr that can + * be added to a single segment. */ static inline unsigned get_max_segment_size(const struct queue_limits *lim, - struct page *start_page, unsigned long offset) + phys_addr_t paddr, unsigned int len) { - unsigned long mask = lim->seg_boundary_mask; - - offset = mask & (page_to_phys(start_page) + offset); - /* * Prevent an overflow if mask = ULONG_MAX and offset = 0 by adding 1 * after having calculated the minimum. */ - return min(mask - offset, (unsigned long)lim->max_segment_size - 1) + 1; + return min_t(unsigned long, len, + min(lim->seg_boundary_mask - (lim->seg_boundary_mask & paddr), + (unsigned long)lim->max_segment_size - 1) + 1); } /** @@ -258,9 +257,7 @@ static bool bvec_split_segs(const struct queue_limits *lim, unsigned seg_size = 0; while (len && *nsegs < max_segs) { - seg_size = get_max_segment_size(lim, bv->bv_page, - bv->bv_offset + total_len); - seg_size = min(seg_size, len); + seg_size = get_max_segment_size(lim, bvec_phys(bv) + total_len, len); (*nsegs)++; total_len += seg_size; @@ -494,8 +491,8 @@ static unsigned blk_bvec_map_sg(struct request_queue *q, while (nbytes > 0) { unsigned offset = bvec->bv_offset + total; - unsigned len = min(get_max_segment_size(&q->limits, - bvec->bv_page, offset), nbytes); + unsigned len = get_max_segment_size(&q->limits, bvec_phys(bvec), + nbytes); struct page *page = bvec->bv_page; /*
Work on a single address to simplify the logic, and prepare the callers from using better helpers. Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/blk-merge.c | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-)