From: Akira Fujita <a-fujita@rs.jp.nec.com>
Subject: Re: [RFC][PATCH] ext4: Fix overflow of metadata block reservation
 counter
Date: Fri, 04 Feb 2011 14:46:05 +0900
Message-ID: <4D4B929D.3090601@rs.jp.nec.com>
References: <4D33FDF6.5040700@rs.jp.nec.com> <87tyh7x01i.fsf@dmon-lp.sw.ru> <4D34E68B.3070804@rs.jp.nec.com>
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Cc: ext4 development <linux-ext4@vger.kernel.org>
To: Dmitry <dmonakhov@openvz.org>
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Hi Dmitry,

Could you reproduce this?
It still occurs on 2.6.38-rc3...

Feb  4 09:19:43 TNESG9423 kernel: [  770.742185] EXT4-fs (sda9): delayed block allocation failed for inode 13 at logical offset 36019 with max blocks 64 with error -28
Feb  4 09:19:43 TNESG9423 kernel: [  770.742253] EXT4-fs (sda9): This should not happen!! Data will be lost
Feb  4 09:19:43 TNESG9423 kernel: [  770.742255]
Feb  4 09:19:43 TNESG9423 kernel: [  770.742298] Total free blocks count 0
Feb  4 09:19:43 TNESG9423 kernel: [  770.742318] Free/Dirty block details
Feb  4 09:19:43 TNESG9423 kernel: [  770.742339] free_blocks=0
Feb  4 09:19:43 TNESG9423 kernel: [  770.742355] dirty_blocks=-4294926403
Feb  4 09:19:43 TNESG9423 kernel: [  770.742375] Block reservation details
Feb  4 09:19:43 TNESG9423 kernel: [  770.742395] i_reserved_data_blocks=40781
Feb  4 09:19:43 TNESG9423 kernel: [  770.742417] i_reserved_meta_blocks=112
Feb  4 09:19:43 TNESG9423 kernel: [  770.742617] EXT4-fs (sda9): delayed block allocation failed for inode 13 at logical offset 36019 with max blocks 64 with error -28
Feb  4 09:19:43 TNESG9423 kernel: [  770.742675] EXT4-fs (sda9): This should not happen!! Data will be lost
Feb  4 09:19:43 TNESG9423 kernel: [  770.742677]
Feb  4 09:19:43 TNESG9423 kernel: [  770.742718] Total free blocks count 0
Feb  4 09:19:43 TNESG9423 kernel: [  770.742738] Free/Dirty block details
Feb  4 09:19:43 TNESG9423 kernel: [  770.742757] free_blocks=0
Feb  4 09:19:43 TNESG9423 kernel: [  770.742772] dirty_blocks=-4294926403
Feb  4 09:19:43 TNESG9423 kernel: [  770.742792] Block reservation details
Feb  4 09:19:43 TNESG9423 kernel: [  770.742812] i_reserved_data_blocks=40781
Feb  4 09:19:43 TNESG9423 kernel: [  770.742833] i_reserved_meta_blocks=112
Feb  4 09:19:43 TNESG9423 kernel: [  770.742878] ------------[ cut here ]------------
Feb  4 09:19:43 TNESG9423 kernel: [  770.742902] kernel BUG at fs/ext4/inode.c:2188!
Feb  4 09:19:43 TNESG9423 kernel: [  770.742926] invalid opcode: 0000 [#1] SMP
Feb  4 09:19:43 TNESG9423 kernel: [  770.742954] last sysfs file: /sys/devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda9/alignment_offset
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] CPU 1
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] Modules linked in: ext4 jbd2 crc16 ip6table_filter ip6_tables sunrpc p4_clockmod freq_table speedstep_lib ipv6 uinput ppdev parport_pc parport pcspkr
i2c_i801 iTCO_wdt iTCO_vendor_support e1000e pata_acpi ata_generic pata_via i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: microcode]
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] Pid: 2212, comm: flush-8:0 Not tainted 2.6.38-rc3 #1 MS-7264BLM/PC-MJ18ABZR4
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] RIP: 0010:[<ffffffffa02278be>]  [<ffffffffa02278be>] ext4_da_block_invalidatepages+0x81/0x119 [ext4]
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] RSP: 0018:ffff88007b0d5750  EFLAGS: 00010246
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] RAX: 000000000000000e RBX: 0000000000008cf2 RCX: ffff88007b0d5780
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] RDX: 0000000000000000 RSI: 0100000000000000 RDI: ffffea0000ab3610
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] RBP: ffff88007b0d5820 R08: ffff88007b0d5690 R09: 0000000000000001
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] R10: ffff88002fe49880 R11: ffff88002fe49880 R12: ffff88007b0d5770
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] R13: ffff88007b0d5780 R14: ffff880025c7c1f8 R15: ffffea0000ab3338
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] FS:  0000000000000000(0000) GS:ffff88007f480000(0000) knlGS:0000000000000000
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] CR2: 0000003680ae1560 CR3: 0000000079d19000 CR4: 00000000000006e0
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] Process flush-8:0 (pid: 2212, threadinfo ffff88007b0d4000, task ffff88007b29e900)
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] Stack:
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  372e30373720205b 00205d3333383234 ffff880000000020 ffff88007b0d57c0
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  000000000000000e ffff8800000000a7 ffffea0000ab3338 ffffea0000ab3370
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  ffffea0000ab33a8 ffffea0000ab33e0 ffffea0000ab3418 ffffea0000ab3450
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] Call Trace:
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffffa022afb8>] mpage_da_map_and_submit+0x203/0x2f4 [ext4]
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffffa022b177>] mpage_add_bh_to_extent+0xce/0xdd [ext4]
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffffa022bcf0>] write_cache_pages_da+0x29f/0x3a7 [ext4]
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffffa022c10b>] ext4_da_writepages+0x313/0x50c [ext4]
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff814e148c>] ? kmemleak_free+0x26/0x45
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff810b8e92>] do_writepages+0x21/0x2a
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff810b1658>] __filemap_fdatawrite_range+0x50/0x52
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff810b1bc4>] filemap_fdatawrite_range+0x13/0x15
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffffa02080dc>] jbd2_journal_begin_ordered_truncate+0x6d/0x90 [jbd2]
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffffa0225c98>] ext4_begin_ordered_truncate+0x6d/0x76 [ext4]
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffffa022abbc>] ext4_evict_inode+0x81/0x27a [ext4]
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff8110057b>] evict+0x24/0x8d
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff81100aed>] iput+0x1e9/0x21a
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff8110a806>] writeback_sb_inodes+0xb3/0x102
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff8110b092>] writeback_inodes_wb+0xfd/0x10f
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff8110b2d3>] wb_writeback+0x22f/0x34a
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff810b8116>] ? determine_dirtyable_memory+0x1a/0x2d
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff8110b5cc>] wb_do_writeback+0x1de/0x1fe
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff810491cd>] ? process_timeout+0x0/0x10
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff8110b6af>] bdi_writeback_thread+0xc3/0x1f8
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff8110b5ec>] ? bdi_writeback_thread+0x0/0x1f8
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff8110b5ec>] ? bdi_writeback_thread+0x0/0x1f8
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff810567dd>] kthread+0x82/0x8a
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff81003894>] kernel_thread_helper+0x4/0x10
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff8105675b>] ? kthread+0x0/0x8a
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  [<ffffffff81003890>] ? kernel_thread_helper+0x0/0x10
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] Code: 89 f6 4c 89 e7 e8 dd 1d e9 e0 85 c0 0f 84 9f 00 00 00 4c 89 e9 31 d2 eb 68 4c 8b 39 49 39 5f 20 77 63 49 8b 37 40 80 e6 01 75 04 <0f> 0b eb fe 49
8b 37 48 83 c1 08 f7 c6 00 20 00 00 74 04 0f 0b
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001] RIP  [<ffffffffa02278be>] ext4_da_block_invalidatepages+0x81/0x119 [ext4]
Feb  4 09:19:43 TNESG9423 kernel: [  770.743001]  RSP <ffff88007b0d5750>
Feb  4 09:19:43 TNESG9423 kernel: [  770.833820] ---[ end trace d27d30499e24ac96 ]---
Feb  4 09:19:43 TNESG9423 kernel: [  770.835481] flush-8:0 used greatest stack depth: 2960 bytes left



(2011/01/18 10:02), Akira Fujita wrote:
> 
> 
> (2011/01/17 20:05), Dmitry wrote:
>> On Mon, 17 Jan 2011 17:29:42 +0900, Akira Fujita<a-fujita@rs.jp.nec.com>   wrote:
>>> Hi,
>>>
>>> The metadata block reservation counter overflows with data write
>>> on ext4 (indirect block map) when its disk space is almost full.
>>> This overflow triggers following BUG_ON.
>>>
>>> Jan 14 09:36:48 TNESG9423 kernel: ------------[ cut here ]------------
>>> Jan 14 09:36:48 TNESG9423 kernel: kernel BUG at fs/ext4/inode.c:2170!
>>> Jan 14 09:36:48 TNESG9423 kernel: invalid opcode: 0000 [#1] SMP
>>> Jan 14 09:36:48 TNESG9423 kernel: last sysfs file: /sys/kernel/mm/ksm/run
>>> Jan 14 09:36:48 TNESG9423 kernel: CPU 0
>>> Jan 14 09:36:48 TNESG9423 kernel: Modules linked in: ip6table_filter ip6_tables ebtable_nat ebtables xt_CHECKSUM iptable_mangle ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4
>>> xt_state nf_conntrack ipt_REJECT bridge stp llc autofs4 sunrpc p4_clockmod freq_table speedstep_lib ipv6 xt_physdev iptable_filter ip_tables nls_utf8 dm_mirror dm_region_hash dm_log dm_mod kvm_intel
>>> kvm uinput ppdev parport_pc parport sg pcspkr i2c_i801 iTCO_wdt iTCO_vendor_support snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore
>>> snd_page_alloc e1000e ext3 jbd sd_mod crc_t10dif sr_mod cdrom pata_via pata_acpi ata_generic ata_piix i915 drm_kms_helper drm i2c_algo_bit i2c_core video output [last unloaded: mperf]
>>> Jan 14 09:36:48 TNESG9423 kernel:
>>> Jan 14 09:36:48 TNESG9423 kernel: Pid: 937, comm: flush-8:0 Not tainted 2.6.37 #1 MS-7264BLM/PC-MJ18ABZR4
>>> Jan 14 09:36:48 TNESG9423 kernel: RIP: 0010:[<ffffffff811c5298>]  [<ffffffff811c5298>] ext4_da_block_invalidatepages+0x168/0x180
>>> Jan 14 09:36:48 TNESG9423 kernel: RSP: 0018:ffff88007613f780  EFLAGS: 00010246
>>> Jan 14 09:36:48 TNESG9423 kernel: RAX: 0010000000000024 RBX: 0000000000008cf2 RCX: 000000000000000e
>>> Jan 14 09:36:48 TNESG9423 kernel: RDX: 000000000000000e RSI: 0000000000000001 RDI: ffffea0000a70d30
>>> Jan 14 09:36:48 TNESG9423 kernel: RBP: ffff88007613f850 R08: 0000000000000001 R09: 0000000000000002
>>> Jan 14 09:36:48 TNESG9423 kernel: R10: ffffea0000a70d38 R11: ffff880035f01b58 R12: ffff88007613f7a0
>>> Jan 14 09:36:48 TNESG9423 kernel: R13: ffff880065eecd68 R14: ffff88007613f7b8 R15: ffffea0000a70a58
>>> Jan 14 09:36:48 TNESG9423 kernel: FS:  0000000000000000(0000) GS:ffff88007f400000(0000) knlGS:0000000000000000
>>> Jan 14 09:36:48 TNESG9423 kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
>>> Jan 14 09:36:48 TNESG9423 kernel: CR2: 0000003680ae1560 CR3: 000000004da45000 CR4: 00000000000006f0
>>> Jan 14 09:36:48 TNESG9423 kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>>> Jan 14 09:36:48 TNESG9423 kernel: DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
>>> Jan 14 09:36:48 TNESG9423 kernel: Process flush-8:0 (pid: 937, threadinfo ffff88007613e000, task ffff8800371b54e0)
>>> Jan 14 09:36:48 TNESG9423 kernel: Stack:
>>> Jan 14 09:36:48 TNESG9423 kernel: ffff88007613f7e0 ffffffff814ee3d6 0000000000000008 0000000e7613f7f0
>>> Jan 14 09:36:48 TNESG9423 kernel: 000000000000000e 000000003741a4b9 ffffea0000a70a58 ffffea0000a70a90
>>> Jan 14 09:36:48 TNESG9423 kernel: ffffea0000a70ac8 ffffea0000a70b00 ffffea0000a70b38 ffffea0000a70b70
>>> Jan 14 09:36:48 TNESG9423 kernel: Call Trace:
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff814ee3d6>] ? printk+0x41/0x43
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff811c9fe4>] mpage_da_map_and_submit+0x274/0x470
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff811ca24d>] mpage_add_bh_to_extent+0x6d/0xf0
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff811ca5a0>] write_cache_pages_da+0x2d0/0x4a0
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff811caa4c>] ext4_da_writepages+0x2dc/0x650
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff81105321>] do_writepages+0x21/0x40
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff810fb55b>] __filemap_fdatawrite_range+0x5b/0x60
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff810fb833>] filemap_fdatawrite_range+0x13/0x20
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff811fb6ce>] jbd2_journal_begin_ordered_truncate+0x8e/0xb0
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff811cd02b>] ext4_evict_inode+0x23b/0x3b0
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff81167477>] evict+0x27/0xc0
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff81167a4b>] iput+0x1bb/0x2a0
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff811734a4>] writeback_sb_inodes+0x104/0x180
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff81173cfd>] writeback_inodes_wb+0x9d/0x160
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff8117404b>] wb_writeback+0x28b/0x400
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff810714cc>] ? lock_timer_base+0x3c/0x70
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff81072092>] ? del_timer_sync+0x22/0x30
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff81174257>] wb_do_writeback+0x97/0x1e0
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff81174452>] bdi_writeback_thread+0xb2/0x270
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff811743a0>] ? bdi_writeback_thread+0x0/0x270
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff811743a0>] ? bdi_writeback_thread+0x0/0x270
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff81083356>] kthread+0x96/0xa0
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff8100ce84>] kernel_thread_helper+0x4/0x10
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff810832c0>] ? kthread+0x0/0xa0
>>> Jan 14 09:36:48 TNESG9423 kernel: [<ffffffff8100ce80>] ? kernel_thread_helper+0x0/0x10
>>> Jan 14 09:36:48 TNESG9423 kernel: Code: a8 00 00 00 5b 41 5c 41 5d 41 5e 41 5f c9 c3 0f 1f 40 00 4c 89 e7 48 89 95 40 ff ff ff e8 01 1b f4 ff 48 8b 95 40 ff ff ff eb c9<0f>   0b eb fe 0f 0b 66 90 eb fc
>>> 66 66 66 66 66 2e 0f 1f 84 00 00
>>> Jan 14 09:36:48 TNESG9423 kernel: RIP  [<ffffffff811c5298>] ext4_da_block_invalidatepages+0x168/0x180
>>> Jan 14 09:36:48 TNESG9423 kernel: RSP<ffff88007613f780>
>>> Jan 14 09:36:48 TNESG9423 kernel: ---[ end trace 0496eaed3b9ec629 ]---
>>>
>>> To fix this, I referred to the patch which is for data blocks
>>> reservation counter (commit: ef627929781c98113e6ae93f159dd3c12a884ad8)
>> I cant find that commit in  linus's, and tytso's tries, can you please
>> specify where it can be found.
> 
> Oops, commit ef627929781c98113e6ae93f159dd3c12a884ad8 is on
> http://lkml.indiana.edu/hypermail/linux/kernel/0912.3/01475.html,
> but actually it's incorrect. The correct commit is
> 61820f33e1bcadff14af25a4a894240e7903dd3d in ext4 patch queue.
> 
> 
>>> and made a following patch which prints metadata block inconsistency
>>> and corrects it.
>>> My patch is trial, if you have better idea, feel free to fix this bug.
>>>
>>> # You can reproduce this problem with attached programs.
>>> # In my environment, this occurs in 1 minute.
>>>
>>> Signed-off-by: Akira Fujita<a-fujita@rs.jp.nec.com>
>>> ---
>>>    fs/ext4/inode.c |   10 ++++++++++
>>>    1 file changed, 10 insertions(+)
>>> diff -Nrup -X linux-2.6.37-org/Documentation/dontdiff linux-2.6.37-org/fs/ext4/inode.c linux-2.6.37/fs/ext4/inode.c
>>> --- linux-2.6.37-org/fs/ext4/inode.c	2011-01-17 15:47:59.000000000 +0900
>>> +++ linux-2.6.37/fs/ext4/inode.c	2011-01-17 15:52:25.000000000 +0900
>>> @@ -1127,6 +1127,16 @@ void ext4_da_update_reserve_space(struct
>>>    		used = ei->i_reserved_data_blocks;
>>>    	}
>>>
>>> +	if (unlikely(ei->i_allocated_meta_blocks>
>>> +			ei->i_reserved_meta_blocks)) {
>>> +		ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, "
>>> +			"meta blocks %d with only %d reserved meta blocks\n",
>>> +			__func__, inode->i_ino, ei->i_allocated_meta_blocks,
>>> +			ei->i_reserved_meta_blocks);
>>> +		WARN_ON(1);
>>> +		ei->i_allocated_meta_blocks = ei->i_reserved_meta_blocks;
>>> +	}
>>> +
>> The situation where allocated>   reservation is a very nasty bug and
>> means what reservation is broken, so next moment result in user data
>> drop/corruption, due to ENOSPC, so we definitely have to investigate
>> the root of cause. BTW i cant reproduce the bug with your test
>> on 2.6.34.7-63.fc13 which is really old, but still.
>> Which version should i use to reproduce the issue?
> 
> My kernel is 2.6.37 + ext4 patch queue (2741742fcfca2e19cd26b1cfe8e43e7b444c8e35).
> [akira@bsd086 ~]$ uname -a
> Linux bsd086.bsd.tnes.nec.co.jp 2.6.37 #6 SMP Mon Jan 17 11:54:42 JST 2011 x86_64 x86_64 x86_64 GNU/Linux
> 
> 
>>>    	/* Update per-inode reservations */
>>>    	ei->i_reserved_data_blocks -= used;
>>>    	ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks;
>> Attachment: metadata_blocks_overflow.sh (application/x-shellscript)
>>> #include<stdio.h>
>>> #include<stdlib.h>
>>> #include<unistd.h>
>>> #include<string.h>
>>> #include<sys/file.h>
>>> #include<sys/mman.h>
>>> #include<sys/uio.h>
>>> #include<sys/wait.h>
>>> #include<errno.h>
>>> #include<malloc.h>
>>>
>>> #define	BUFSIZE	4096
>>> #define PATH_MAX 4096
>>> #define	MINIOSIZE 4*1024
>>> #define	MAXIOSIZE 4*1024*1024
>>>
>>> #ifndef O_DIRECT
>>> #define O_DIRECT 040000
>>> #endif
>>>
>>> static int	bufsize = 0;		/* Buffersize. Default random */
>>> static int	bufsize_random = 1;	/* Buffersize random flag. Default random */
>>> static long long	filesize = 0;	/* Target file size */
>>> static long long	target_range = 0;	/* Target range per process */
>>> static int	files_num = 0;
>>> static char	*filenames;
>>> static int	mmap_write = 0;
>>> static int	o_sync = 0;
>>> static int	o_async = 0;
>>> static int	o_direct = 0;
>>>
>>> static void setup(void);
>>> static void cleanup(void);
>>>
>>> void prg_usage()
>>> {
>>> 	fprintf(stderr, "Usage: fs_write [-S 0|1] [-D] [-n num_process]\n");
>>> 	fprintf(stderr, "                -s file_size file...\n");
>>> 	fprintf(stderr, "\n");
>>> 	fprintf(stderr, "		-S	sync mode (0:O_ASYNC 1:O_SYNC)\n");
>>> 	fprintf(stderr, "		-D	Direct IO\n");
>>> 	fprintf(stderr, "		-n	Process count (default is 1)\n");
>>> 	fprintf(stderr, "		-s	File size\n");
>>> 	fprintf(stderr, "		file...	Traget file\n");
>>>
>>> 	exit(1);
>>> }
>>>
>>> int runtest(int fd_w[], int childnum)
>>> {
>>> 	int num = 0;
>>> 	int err = 0;
>>> 	long long offset = target_range * childnum;
>>> 	long long  remain = target_range;
>>> 	int len = bufsize;
>>> 	int write_len = 0;
>>> 	int psize = getpagesize();
>>> 	int max_page = MAXIOSIZE / psize;
>>> 	char *buf_w;
>>> 	void *p;
>>>
>>> 	buf_w = (char*)memalign(psize, MAXIOSIZE);
>>>
>>> 	while (remain>   0) {
>>> 		if (bufsize_random == 1) {
>>> 			len = (rand() % max_page) * psize;
>>> 			if (!len)
>>> 				len = MINIOSIZE;
>>> 		}
>>> 		if (len>   remain)
>>> 			len = remain;
>>>
>>> 		for (num = 0; num<   files_num ; num++) {
>>> 			memset(buf_w, childnum+num, len);
>>> 			if (!mmap_write) {
>>> 				if (lseek(fd_w[num], offset, SEEK_SET)<   0) {
>>> 					err = errno;
>>> 					goto out;
>>> 				}
>>> 				if ((write_len = write(fd_w[num], buf_w, len))<   0) {
>>> 					err = errno;
>>> 					goto out;
>>> 				}
>>> 				if (len != write_len)
>>> 					goto out;
>>> 			} else {
>>> 				p = mmap(NULL, len, PROT_WRITE, MAP_SHARED,
>>> 							fd_w[num], offset);
>>> 				if (p == MAP_FAILED) {
>>> 					err = errno;
>>> 					goto out;
>>> 				}
>>> 				memcpy(p, buf_w, len);
>>> 				if (munmap(p, len) == -1) {
>>> 					err = errno;
>>> 					goto out;
>>> 				}
>>> 			}
>>> 		}
>>> 		offset += len;
>>> 		remain -= len;
>>> 	}
>>>
>>> out:
>>> 	if (err == ENOSPC || len != write_len)
>>> 		err = 0;
>>> 	if (err>   0)
>>> 		fprintf(stderr, "%s;\n", strerror(err));
>>> 	free(buf_w);
>>>
>>> 	return err;
>>> }
>>>
>>> int child_function(int childnum)
>>> {
>>> 	int num, ret = -1;
>>> 	int fd_w[files_num];
>>> 	char *filename;
>>> 	
>>> 	for (num = 0; num<   files_num ; num++) {
>>> 		fd_w[num] = -1;
>>> 	}
>>> 	for (num = 0; num<   files_num ; num++) {
>>> 		filename = filenames + (num*PATH_MAX);
>>> 		if ((fd_w[num] = open(filename,
>>> 				O_RDWR|o_sync|o_async|o_direct))<   0) {
>>> 			printf("TINFO:fd_w open failed for %s: %s\n",filename, strerror(errno));
>>> 			goto out;
>>> 		}
>>> 	}
>>>
>>> 	ret = runtest(fd_w, childnum);
>>>
>>> out:
>>> 	for (num = 0; num<   files_num ; num++) {
>>> 		if (fd_w[num] != -1)
>>> 			close(fd_w[num]);
>>> 	}
>>>
>>> 	exit(ret);
>>> }
>>>
>>> static void setup(void)
>>> {
>>> 	int num, fd;
>>> 	char *filename;
>>>
>>> 	for (num = 0; num<   files_num; num++) {
>>> 		filename = filenames + (num * PATH_MAX);
>>> 		if ((fd = open(filename, O_CREAT|O_EXCL|O_WRONLY|O_TRUNC, 0666))<   0) {
>>> 			printf("TBROK, Couldn't create test file %s: %s\n", filename, strerror(errno));
>>> 			cleanup();
>>> 		}
>>>
>>> 		if (mmap_write) {
>>> 			if (ftruncate(fd, filesize)<   0) {
>>> 				printf("TBROK2: Couldn't create test file %s: %s\n", filename, strerror(errno));
>>> 				cleanup();
>>> 			}
>>> 		}
>>> 		close(fd);
>>> 	}
>>> }
>>>
>>> static void cleanup(void)
>>> {
>>> 	int num;
>>> 	for (num = 0; num<   files_num; num++)
>>> 		unlink(filenames + (num * PATH_MAX));
>>> 	free(filenames);
>>> 	exit(1);
>>> }
>>>
>>> int main(int argc, char *argv[])
>>> {
>>> 	int	numchild = 1;	/* Number of children. Default 5 */
>>> 	int	i, num;
>>> 	int	err = 0;
>>> 	int	sync_mode = 0;
>>> 	int	*cpid;
>>> 	int 	status;
>>>
>>> 	while ((i = getopt(argc, argv, "MS:Dn:s:")) != -1) {
>>> 		switch(i) {
>>> 		case 'M':
>>> 			mmap_write = 1;
>>> 			break;
>>> 		case 'S':
>>> 			if ((sync_mode = atoi(optarg))<   0) {
>>> 				fprintf(stderr, "sync mode must be 0 or 1;\n");
>>> 				prg_usage();
>>> 			}
>>> 			switch (sync_mode) {
>>> 			case 0:
>>> 				o_async = O_ASYNC;
>>> 				break;
>>> 			case 1:
>>> 				o_sync = O_SYNC;
>>> 				break;
>>> 			default:
>>> 				fprintf(stderr, "sync mode must be 0 or 1;\n");
>>> 				prg_usage();
>>> 			}
>>> 			break;
>>> 		case 'D':
>>> 			o_direct = O_DIRECT;
>>> 			break;
>>> 		case 'n':
>>> 			if ((numchild = atoi(optarg))<= 0) {
>>> 				fprintf(stderr, "no of children must be>   0;\n");
>>> 				prg_usage();
>>> 			}
>>> 			break;
>>> 		case 's':
>>> 			filesize = atol(optarg);
>>> 			if (filesize<= 0) {
>>> 				fprintf(stderr, "filesize must be>   0;\n");
>>> 				prg_usage();
>>> 			}
>>> 			break;
>>> 		default:
>>> 			prg_usage();
>>> 		}
>>> 	}
>>>
>>> 	files_num = argc - optind;
>>> 	if (files_num<= 0)
>>> 		prg_usage();
>>> 	if (filesize % numchild != 0 || (filesize / numchild) % BUFSIZE != 0) {
>>> 		fprintf(stderr, "filesize must be multiple of 4k*numchild:"
>>> 				"filesize=%lld;\n", filesize);
>>> 		prg_usage();
>>> 	}
>>>
>>> 	if ((filenames = (char *)malloc(files_num * PATH_MAX)) == NULL ||
>>> 	    (cpid = (int *)malloc(sizeof(int)*numchild)) == NULL) {
>>> 		perror("malloc");
>>> 		exit(1);
>>> 	}
>>> 	for(i = optind, num = 0 ; i<   argc; i++, num++)
>>> 		strcpy((char *)filenames + (num * PATH_MAX), argv[i]);
>>> 	target_range = filesize / numchild;
>>>
>>>
>>> 	setup();
>>>
>>> 	for(i = 0; i<   numchild; i++) {
>>> 		*(cpid+i) = fork();
>>> 		if (*(cpid+i) == 0)
>>> 			child_function(i);
>>> 	}
>>> 	for(i = 0; i<   numchild; i++) {
>>> 		waitpid(*(cpid+1),&status, 0);
>>> 	}
>>>
>>> 	cleanup();
>>> 	return err;
>>> }
>>
> 

-- 
Akira Fujita <a-fujita@rs.jp.nec.com>

The First Fundamental Software Development Group,
Software Development Division,
NEC Software Tohoku, Ltd.