On Thu, Jul 9, 2015 at 3:41 PM, Dave Chinner <david@xxxxxxxxxxxxx> wrote: > On Wed, Jul 08, 2015 at 11:54:04PM -0700, Ming Lin wrote: >> On Wed, 2015-07-08 at 16:40 -0700, Ming Lin wrote: >> > On Wed, 2015-07-08 at 06:57 -0700, Ming Lin wrote: >> > > On Wed, 2015-07-08 at 10:53 +0200, Christoph Hellwig wrote: >> > > > On Wed, Jul 08, 2015 at 12:01:53AM -0700, Ming Lin wrote: >> > > > > Hi list, >> > > > > >> > > > > I am testing some direct-io patches. >> > > > > xfs_tests/xfs/080 failed. >> > > > > >> > > > > It's strange. >> > > > > There is no hole in "rwtest.file", >> > > > > but when read it at some offset it returns zero because of hole. >> > > > > >> > > > > root@block:~# xfs_io -c bmap /mnt/test/rwtest.file >> > > > > /mnt/test/rwtest.file: >> > > > > 0: [0..125671]: 160..125831 >> > > > >> > > > Sounds like you see an unwritten extent. What does xfs_bmap -pv show on >> > > > the file? >> > > >> > > root@block:~# xfs_bmap -pv /mnt/test/rwtest.file >> > > /mnt/test/rwtest.file: >> > > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL FLAGS >> > > 0: [0..743]: 160..903 0 (160..903) 744 00000 >> > > 1: [744..783]: 904..943 0 (904..943) 40 10000 >> > > 2: [784..951]: 944..1111 0 (944..1111) 168 00000 >> > > 3: [952..1023]: 1112..1183 0 (1112..1183) 72 10000 >> > > 4: [1024..1287]: 1184..1447 0 (1184..1447) 264 00000 >> > > 5: [1288..1383]: 1448..1543 0 (1448..1543) 96 10000 >> > >> > file offset 659456 is in EXT 5. >> > I guess FLAGS 1 means it's an unwritten extent, right? >> > >> > xfs_tests/xfs/080 basically does: >> > 1. direct io write >> > 2. then buffered read to check the previous dio write >> > >> > Here is an example of error logs. >> > >> > doio ( 3626) 16:13:23 >> > --------------------- >> > *** DATA COMPARISON ERROR *** >> > check_file(/mnt/test/rwtest.file, 239616, 81408, H:3626:block:doio*, >> > 18, 0) failed >> > >> > Comparison fd is 5, with open flags 0 >> > Corrupt regions follow - unprintable chars are represented as '.' >> > ----------------------------------------------------------------- >> > corrupt bytes starting at file offset 241664 >> > 1st 32 expected bytes: oio*H:3626:block:doio*H:3626:blo >> > 1st 32 actual bytes: ................................ >> > >> > Request number 981 >> > fd 4 is file /mnt/test/rwtest.file - open flags are 040001 >> > O_WRONLY,O_DIRECT, >> > write done at file offset 239616 - pattern is H (0110) >> > number of requests is 1, strides per request is 1 >> > i/o byte count = 81408 >> > memory alignment is aligned >> > DIRECT I/O: offset % 512 = 0 length % 81408 = 0 >> > mem alignment 0x200 xfer size: small: 512 large: 2147483136 >> > >> > syscall: writev(4, (iov on stack), 1) >> > >> > >> > The "expected bytes" was actually written to the disk successfully, >> > but for some bug the xfs extent flag was not set correctly. >> > The flag should be "XFS_EXT_NORM", but now it's "XFS_EXT_UNWRITTEN". >> > >> > Could you share the code path the extent flag was updated? >> > Is it also updated through direct io? >> >> For XFS direct IO, are below the only 2 paths to convert unwritten >> extent to written extent? >> >> [ 72.279043] Call Trace: >> [ 72.279719] [<ffffffff8169c2f3>] dump_stack+0x4f/0x7b >> [ 72.280898] [<ffffffff8127140f>] xfs_bmapi_convert_unwritten+0x73/0x176 >> [ 72.282393] [<ffffffff8127a233>] xfs_bmapi_write+0x2a0/0x7ee >> [ 72.283705] [<ffffffff812b8ae8>] xfs_iomap_write_direct+0x23e/0x2f0 >> [ 72.285132] [<ffffffff8129ef88>] __xfs_get_blocks+0x14c/0xf6c >> [ 72.286456] [<ffffffff8103d74b>] ? get_user_pages_fast+0xee/0x14c >> [ 72.287847] [<ffffffff8129fdcf>] xfs_get_blocks_direct+0x14/0x16 >> [ 72.289246] [<ffffffff811879c6>] get_blocks+0x86/0x182 >> [ 72.297467] [<ffffffff8103d74b>] ? get_user_pages_fast+0xee/0x14c >> [ 72.298845] [<ffffffff81187fe6>] __blockdev_direct_IO+0x372/0x666 >> [ 72.300266] [<ffffffff8129fdbb>] ? xfs_get_blocks+0x13/0x13 >> [ 72.301555] [<ffffffff8116f9ac>] ? __mnt_drop_write_file+0x12/0x14 >> [ 72.302936] [<ffffffff8116a017>] ? file_update_time+0xb5/0xcb >> [ 72.304279] [<ffffffff8129d890>] xfs_vm_direct_IO+0x89/0x90 >> [ 72.305555] [<ffffffff8129d943>] ? xfs_setfilesize_trans_alloc+0xac/0xac >> [ 72.307064] [<ffffffff8169ae5e>] xfs_file_dio_aio_write+0x2e0/0x449 >> [ 72.308509] [<ffffffff813e1028>] ? __clear_user+0x36/0x5b >> [ 72.309755] [<ffffffff812af9c6>] xfs_file_write_iter+0x75/0x105 >> [ 72.311107] [<ffffffff81151524>] __vfs_write+0x97/0xc0 >> [ 72.312347] [<ffffffff81151b1f>] vfs_write+0xb5/0x16f >> [ 72.313526] [<ffffffff811522c3>] SyS_write+0x4a/0x94 >> [ 72.314683] [<ffffffff816a4b17>] system_call_fastpath+0x12/0x6f > > There should not be unwritten extent conversion happening through > the allocation path here. Indeed, xfs_iomap_write_direct() only uses > the XFS_BMAPI_PREALLOC flag, which means > xfs_bmapi_convert_unwritten() returns without doing anything to the > newly allocated extent... > >> [ 72.328096] Call Trace: >> [ 72.328786] [<ffffffff8169c2f3>] dump_stack+0x4f/0x7b >> [ 72.330002] [<ffffffff8127140f>] xfs_bmapi_convert_unwritten+0x73/0x176 >> [ 72.331565] [<ffffffff8126cd9d>] ? xfs_bmap_search_extents+0x60/0xd6 >> [ 72.333059] [<ffffffff812c96f1>] ? kmem_zone_alloc+0x6e/0xba >> [ 72.334412] [<ffffffff8127a233>] xfs_bmapi_write+0x2a0/0x7ee >> [ 72.335777] [<ffffffff812b9455>] xfs_iomap_write_unwritten+0x205/0x413 >> [ 72.337300] [<ffffffff8129d7e2>] xfs_end_io+0x50/0x75 >> [ 72.338495] [<ffffffff8129dab9>] xfs_end_io_direct_write+0x176/0x26c >> [ 72.339952] [<ffffffff810d20a4>] ? delayacct_end+0x55/0x5e >> [ 72.341238] [<ffffffff8118759d>] dio_complete+0x7c/0x134 >> [ 72.342488] [<ffffffff811882a7>] __blockdev_direct_IO+0x633/0x666 >> [ 72.343908] [<ffffffff8129fdbb>] ? xfs_get_blocks+0x13/0x13 >> [ 72.345263] [<ffffffff8129d890>] xfs_vm_direct_IO+0x89/0x90 >> [ 72.346598] [<ffffffff8129d943>] ? xfs_setfilesize_trans_alloc+0xac/0xac >> [ 72.348185] [<ffffffff8169ae5e>] xfs_file_dio_aio_write+0x2e0/0x449 >> [ 72.349652] [<ffffffff813e1028>] ? __clear_user+0x36/0x5b >> [ 72.350950] [<ffffffff812af9c6>] xfs_file_write_iter+0x75/0x105 >> [ 72.352369] [<ffffffff81151524>] __vfs_write+0x97/0xc0 >> [ 72.353607] [<ffffffff81151b1f>] vfs_write+0xb5/0x16f >> [ 72.354832] [<ffffffff811522c3>] SyS_write+0x4a/0x94 >> [ 72.356060] [<ffffffff816a4b17>] system_call_fastpath+0x12/0x6f > > This is the only unwritten conversion path that should occur through > direct IO - the IO completion path.... There is a bug in the direct io rewrite patches. I have fixed it here: https://git.kernel.org/cgit/linux/kernel/git/mlin/linux.git/commit/?h=block-dio-rewrite&id=ceeccaa16 Thanks. _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
