(2011/01/17 20:05), Dmitry wrote: > On Mon, 17 Jan 2011 17:29:42 +0900, Akira Fujita<a-fujita@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx> >> --- >> 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@xxxxxxxxxxxxx> The First Fundamental Software Development Group, Software Development Division, NEC Software Tohoku, Ltd. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
