On Mon, Nov 25, 2019 at 09:14:51PM -0600, Goldwyn Rodrigues wrote: > This is an effort to use iomap for direct I/O in btrfs. This would > change the call from __blockdev_direct_io() to iomap_dio_rw(). > > The main objective is to lose the buffer head and use bio defined by > iomap code, and hopefully to use more of generic-FS codebase. > > These patches are based on xfs/iomap-for-next, though I tested it > against the patches on xfs/iomap-for-next on top of v5.4 (there are no > changes to existing iomap patches). > > I have tested it against xfstests/btrfs. > > Changes since v1 > - Incorporated back the efficiency change for inode locking > - Review comments about coding style and git comments > - Merge related patches into one > - Direct read to go through btrfs_direct_IO() > - Removal of no longer used function dio_end_io() I see a lockdep assertion during test btrfs/004 iomap_dio_rw() ... lockdep_assert_held(&inode->i_rwsem); btrfs/004 [15:46:30][ 69.749908] run fstests btrfs/004 at 2019-11-27 15:46:30 [ 70.180401] BTRFS info (device vda): disk space caching is enabled [ 70.183496] BTRFS info (device vda): has skinny extents [ 70.378865] BTRFS: device fsid a10200b4-f17d-49a0-8c82-b06b69871613 devid 1 transid 5 /dev/vdb scanned by mkfs.btrfs (21271) [ 70.405858] BTRFS info (device vdb): turning on discard [ 70.408279] BTRFS info (device vdb): disk space caching is enabled [ 70.410630] BTRFS info (device vdb): has skinny extents [ 70.412358] BTRFS info (device vdb): flagging fs with big metadata feature [ 70.420386] BTRFS info (device vdb): checking UUID tree [ 70.427675] ------------[ cut here ]------------ [ 70.429375] WARNING: CPU: 2 PID: 21300 at fs/iomap/direct-io.c:413 iomap_dio_rw+0x255/0x560 [ 70.432208] Modules linked in: xxhash_generic btrfs blake2b_generic libcrc32c crc32c_intel xor zstd_decompress zstd_compress xxhash lzo_compress lzo_decompress raid6_pq loop [ 70.437096] CPU: 2 PID: 21300 Comm: fsstress Not tainted 5.4.0-default+ #881 [ 70.439135] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-rebuilt.opensuse.org 04/01/2014 [ 70.442462] RIP: 0010:iomap_dio_rw+0x255/0x560 [ 70.449092] RSP: 0018:ffffa36dc5b37c80 EFLAGS: 00010246 [ 70.450701] RAX: 0000000000000000 RBX: ffffa36dc5b37e78 RCX: 0000000000000001 [ 70.453062] RDX: ffff88d5b3f75500 RSI: ffff88d5a0c29018 RDI: ffff88d5b3f75d10 [ 70.455308] RBP: ffffa36dc5b37d20 R08: 0000000000000001 R09: ffffffffaef84850 [ 70.457479] R10: ffffa36dc5b37d40 R11: 0000000000007000 R12: ffffa36dc5b37e50 [ 70.459479] R13: 0000000000049000 R14: ffff88d5a0c28ec0 R15: 0000000000049000 [ 70.461790] FS: 00007fab1f5cdb80(0000) GS:ffff88d5bda00000(0000) knlGS:0000000000000000 [ 70.464601] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 70.466503] CR2: 000000000041e000 CR3: 0000000061097006 CR4: 0000000000160ee0 [ 70.468475] Call Trace: [ 70.469477] ? btrfs_direct_IO+0x215/0x360 [btrfs] [ 70.471201] ? __lock_acquired+0x1f0/0x320 [ 70.472837] ? btrfs_direct_IO+0xda/0x360 [btrfs] [ 70.474453] btrfs_direct_IO+0xda/0x360 [btrfs] [ 70.476101] ? lockdep_hardirqs_on+0x103/0x190 [ 70.477732] btrfs_file_write_iter+0x20b/0x5f0 [btrfs] [ 70.479450] ? _copy_to_user+0x76/0x90 [ 70.480943] new_sync_write+0x118/0x1b0 [ 70.482446] vfs_write+0xde/0x1d0 [ 70.483789] ksys_write+0x68/0xe0 [ 70.485136] do_syscall_64+0x50/0x210 [ 70.486578] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 70.488390] RIP: 0033:0x7fab1f7a8f93 [ 70.495054] RSP: 002b:00007ffea7b21208 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 70.497693] RAX: ffffffffffffffda RBX: 0000000000007000 RCX: 00007fab1f7a8f93 [ 70.499708] RDX: 0000000000007000 RSI: 0000000000416000 RDI: 0000000000000003 [ 70.501754] RBP: 0000000000000003 R08: 0000000000416000 R09: 0000000000000231 [ 70.503682] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 [ 70.505622] R13: 0000000000049000 R14: 0000000000416000 R15: 0000000000000000 [ 70.507683] irq event stamp: 1532 [ 70.508931] hardirqs last enabled at (1531): [<ffffffffc01d7bfb>] get_alloc_profile+0x1ab/0x2b0 [btrfs] [ 70.512256] hardirqs last disabled at (1532): [<ffffffffad002a8b>] trace_hardirqs_off_thunk+0x1a/0x1c [ 70.515039] softirqs last enabled at (0): [<ffffffffad07efd0>] copy_process+0x680/0x1b70 [ 70.517193] softirqs last disabled at (0): [<0000000000000000>] 0x0 [ 70.519153] ---[ end trace 7fa25c75a89dbc97 ]--- The branch is xfs/iomap-for-next + this patchset.
