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Date: Wed, 6 Jan 2016 02:39:15 +0000 From: "HUANG Weller (CM/ESW12-CN)" <Weller.Huang@...bosch.com> To: Jan Kara <jack@...e.cz> CC: "linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org> Subject: RE: ext4 out of order when use cfq scheduler > So you are running in 'ws' mode of your tool, am I right? Just looking into the > sources you've sent me I've noticed that although you set O_SYNC in openflg > when mode == MODE_WS, you do not use openflg at all. So file won't be synced > at all. That would well explain why you see that not all file contents is written. So > did you just send me a different version of the source or is your test program > really buggy? > Yes, it is a bug of the test code. So the test tool create files without O_SYNC flag actually. But , even in this case, is the out of order acceptable ? or is it normal ? > > > > > [root@...Fatlas6 ~]# debugfs /dev/nandblk0p3 debugfs 1.42.9 > > > > (28-Dec-2013) > > > > debugfs: imap test/hp0000017aMhWY3i0vMv Inode 390 is part of > > > > block group 0 > > > > located at block 141, offset 0x0280 > > > > > > > > 00000280 80 81 00 00 10 00 04 00 c8 09 00 00 66 0a 00 00 > > > > |............f...| > > > > 00000290 66 0a 00 00 00 00 00 00 00 00 01 00 04 02 00 00 > > > > |f...............| > > > > 000002a0 00 00 08 00 01 00 00 00 0a f3 02 00 04 00 00 00 > > > > |................| > > > > 000002b0 00 00 00 00 00 00 00 00 80 00 00 00 00 2c 01 00 > > > > |.............,..| ==> the file contents is at 0x00012c00 > > > > 000002c0 80 00 00 00 01 00 00 00 8e 26 01 00 00 00 00 00 > > > > |.........&......| > > > > > > > > > > > > Search the block number from the journal blocks: > > > > > > > > [root@...Fatlas6 ~]# hexdump j.bin -C | grep "00 2c 01 00" > > > > 00039ab0 00 00 00 00 00 00 00 00 80 00 00 00 00 2c 01 00 > > > > |.............,..| > > > > > > > > Search file name which the file checksum is error in journal blocks: > > > > > > > > [root@...Fatlas6 ~]# hexdump j.bin -C | grep "3i0vMv" -B1 > > > > 00030c60 86 01 00 00 1c 00 14 01 68 70 30 30 30 30 30 31 > > > > |........hp000001| > > > > 00030c70 37 61 4d 68 57 59 33 69 30 76 4d 76 88 01 00 00 > > > > |7aMhWY3i0vMv....| > > > > > > > > > > > > List all journal block record to check which journal block records it: > > > > > > > > [root@...Fatlas6 ~]# hexdump j.bin -C | grep "c0 3b 39 98" > > > > 00000000 c0 3b 39 98 00 00 00 04 00 00 00 00 00 00 08 00 > > > > |.;9.............| > > > > 00000800 c0 3b 39 98 00 00 00 05 00 00 00 6f 00 00 00 24 > > > > |.;9........o...$| > > > > 00001000 c0 3b 39 98 00 00 00 01 00 00 00 6f 00 00 00 75 > > > > |.;9........o...u| > > > > 0000c800 c0 3b 39 98 00 00 00 02 00 00 00 6f 00 00 00 00 > > > > |.;9........o....| > > > > 0000d000 c0 3b 39 98 00 00 00 01 00 00 00 70 00 00 00 65 > > > > |.;9........p...e| > > > > 00016000 c0 3b 39 98 00 00 00 02 00 00 00 70 00 00 00 00 > > > > |.;9........p....| > > > > 00016800 c0 3b 39 98 00 00 00 01 00 00 00 71 00 00 00 7c > > > > |.;9........q...|| > > > > 00021000 c0 3b 39 98 00 00 00 02 00 00 00 71 00 00 00 00 > > > > |.;9........q....| > > > > 00021800 c0 3b 39 98 00 00 00 01 00 00 00 72 00 00 00 82 > > > > |.;9........r....| > > > > 0002d000 c0 3b 39 98 00 00 00 02 00 00 00 72 00 00 00 00 > > > > |.;9........r....| > > > > 0002d800 c0 3b 39 98 00 00 00 01 00 00 00 73 00 00 00 88 > > > > |.;9........s....| > > > ==>00039ab0 is in last block, the file name and the start block > > > number are all recorded in the journals. > > > > 0003a000 c0 3b 39 98 00 00 00 02 00 00 00 73 00 00 00 00 > > > > |.;9........s....| > > > > > > > > > > > > Back to see the kernel log which it print all the block numbers: > > > > > > > > ... > > > > ... > > > > [ 46.222671] 244109 75277 > > > > [ 46.222693] > > > > [ 46.272438] 244352 75520 > > > > [ 46.272460] > > > > [ 46.348417] 238443 69611 > > > > [ 46.348438] > > > > [ 46.349811] 244480 75648 > > > > [ 46.352287] > > > > [ 46.404904] 244609 75777 > > > > [ 46.404926] > > > > [ 46.454698] 244738 75906 > > > > [ 46.454719] > > > > [ 46.505439] 244992 76160 > > > > [ 46.505459] > > > > [ 46.557783] 245120 76288 > > > > [ 46.557804] > > > > [ 46.610075] 245249 76417 > > > > [ 46.610096] > > > > [ 46.660196] 245378 76546 > > > > [ 46.660219] > > > > [ 46.709906] 201691 32859 ==> journal start is 32768, so the offset is 91, > > > block size=2048, so, the offset address in the j.bin is 0x2d800 > > > > [ 46.709928] J [ 46.711233] > > > > [ 46.740635] drop to 9v > > > > [ 46.749540] 201716 32884 > > > > [ 46.749560] J S > > > > [ 46.751039] > > > > [ 46.753151] 245632 76800 ==> 76800 in hex is 0x012c00, it is the same > start > > > block of the file which checksum is error. > > > > [ 46.755284] > > > > nanddisk idle -> 1. > > > > [ 46.800227] 6v irq-2 > > > > > > > > > > > > The j.bin offset 0x2d800 > > > > > > > > 0002d800 c0 3b 39 98 00 00 00 01 00 00 00 73 00 00 00 88 > > > > |.;9........s....| ==>00039ab0 is in last block > > > > 0003a000 c0 3b 39 98 00 00 00 02 00 00 00 73 00 00 00 00 > > > > |.;9........s....| > > > > > > > > > > > > Normally, ext4 will first write the file contents, and then write > > > > the journal and journal commit. Then after some delay, it will > > > > write the meta data. So The journal blocks contains the meta data > > > > of the file which the file contents already been written before. > > > > But from above analysis, the journal sequence 0x73 already > > > > contain the file > > > > name(hp0000017aMhWY3i0vMv) and the start block number(76800). So > > > > from the kernel log, the block > > > > number(76800) should be available before the journal blocks but > > > > NOT after it. It seems that there is out of order happen. > > > > > > > > Could you please help to check this issue ? or give a explanation > > > > about it ? Many thanks. > > > > > > > > Best regards > > > > > > > > Weller HUANG > > > > > > > > > > > > -- > > > > To unsubscribe from this list: send the line "unsubscribe linux-ext4" > > > > in the body of a message to majordomo@...r.kernel.org More > > > > majordomo info at http://vger.kernel.org/majordomo-info.html > > > -- > > > Jan Kara <jack@...e.com> > > > SUSE Labs, CR > > > > -- > Jan Kara <jack@...e.com> > SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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