zfs/config
Tim Chase 88fa992878 Fix sync behavior for disk vdevs
Prior to b39c22b, which was first generally available in the 0.6.5
release as b39c22b, ZoL never actually submitted synchronous read or write
requests to the Linux block layer.  This means the vdev_disk_dio_is_sync()
function had always returned false and, therefore, the completion in
dio_request_t.dr_comp was never actually used.

In b39c22b, synchronous ZIO operations were translated to synchronous
BIO requests in vdev_disk_io_start().  The follow-on commits 5592404 and
aa159af fixed several problems introduced by b39c22b.  In particular,
5592404 introduced the new flag parameter "wait" to __vdev_disk_physio()
but under ZoL, since vdev_disk_physio() is never actually used, the wait
flag was always zero so the new code had no effect other than to cause
a bug in the use of the dio_request_t.dr_comp which was fixed by aa159af.

The original rationale for introducing synchronous operations in b39c22b
was to hurry certains requests through the BIO layer which would have
otherwise been subject to its unplug timer which would increase the
latency.  This behavior of the unplug timer, however, went away during the
transition of the plug/unplug system between kernels 2.6.32 and 2.6.39.

To handle the unplug timer behavior on 2.6.32-2.6.35 kernels the
BIO_RW_UNPLUG flag is used as a hint to suppress the plugging behavior.

For kernels 2.6.36-2.6.38, the REQ_UNPLUG macro will be available and
ise used for the same purpose.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4858
2017-02-03 10:24:54 -08:00
..
.gitignore Add config/compile to config/.gitignore 2014-10-31 16:25:34 -07:00
Rules.am Use large stacks when available 2017-02-03 10:24:22 -08:00
always-no-bool-compare.m4 Disable gcc bool-compare warning 2015-07-13 12:55:26 -07:00
always-no-unused-but-set-variable.m4 config: compile test rather than run test 2014-03-20 12:11:57 -07:00
config.awk Add build system 2010-08-31 13:41:27 -07:00
deb.am Fix some minor issues with the SYSV init and initramfs scripts. 2015-07-24 15:05:33 -07:00
kernel-acl.m4 Use set_cached_acl and forget_cached_acl when possible 2017-02-03 10:24:50 -08:00
kernel-aio-fsync.m4 Kernel 4.9 compat: file_operations->aio_fsync removal 2017-02-03 10:23:50 -08:00
kernel-automount.m4 Fix snapshot automounting with GrSecurity constify plugin. 2012-08-24 08:56:38 -07:00
kernel-bdev-block-device-operations.m4 3.10 API change: block_device_operations->release() returns void 2013-07-08 15:41:57 -07:00
kernel-bdev-logical-size.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
kernel-bdev-physical-size.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
kernel-bdi-setup-and-register.m4 Linux 4.1 compat: configure bdi_setup_and_register() 2015-08-18 16:43:04 -07:00
kernel-bio-bvec-iter.m4 Linux 3.14 compat: Immutable biovec changes in vdev_disk.c 2014-04-10 14:28:38 -07:00
kernel-bio-end-io-t-args.m4 Linux 4.3 compat: bio_end_io_t / BIO_UPTODATE 2015-09-29 15:27:14 -07:00
kernel-bio-failfast.m4 Linux 2.6.36 compat, use REQ_FAILFAST_MASK and remove pre-2.6.36 support 2015-05-11 15:07:00 -07:00
kernel-bio-op.m4 Linux 4.8 compat: Fix removal of bio->bi_rw member 2016-09-09 13:21:10 -07:00
kernel-bio-rw-barrier.m4 zvol processing should use struct bio 2015-09-04 15:30:24 -04:00
kernel-bio-rw-discard.m4 zvol processing should use struct bio 2015-09-04 15:30:24 -04:00
kernel-blk-queue-flush.m4 Linux 4.7 compat: replace blk_queue_flush with blk_queue_write_cache 2016-09-05 16:07:08 -07:00
kernel-blk-queue-max-hw-sectors.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
kernel-blk-queue-max-segments.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
kernel-blk-queue-unplug.m4 Fix sync behavior for disk vdevs 2017-02-03 10:24:54 -08:00
kernel-blkdev-get-by-path.m4 When checking for symbol exports, try compiling. 2012-07-26 13:42:57 -07:00
kernel-blkdev-get.m4 Move partition scanning from userspace to module. 2012-07-17 09:17:31 -07:00
kernel-block-device-operations-release-void.m4 3.10 API change: block_device_operations->release() returns void 2013-07-08 15:41:57 -07:00
kernel-check-disk-size-change.m4 When checking for symbol exports, try compiling. 2012-07-26 13:42:57 -07:00
kernel-clear-inode.m4 When checking for symbol exports, try compiling. 2012-07-26 13:42:57 -07:00
kernel-commit-metadata.m4 Implement .commit_metadata hook for NFS export 2012-10-03 10:49:45 -07:00
kernel-create-nameidata.m4 Linux 4.2 compat: follow_link() / put_link() 2015-07-17 09:18:16 -07:00
kernel-current_bio_tail.m4 zvol processing should use struct bio 2015-09-04 15:30:24 -04:00
kernel-d-make-root.m4 When checking for symbol exports, try compiling. 2012-07-26 13:42:57 -07:00
kernel-d-obtain-alias.m4 When checking for symbol exports, try compiling. 2012-07-26 13:42:57 -07:00
kernel-d-prune-aliases.m4 Add zfs_sb_prune_aliases() function 2015-06-22 10:22:49 -07:00
kernel-declare-event-class.m4 Swap DTRACE_PROBE* with Linux tracepoints 2014-11-17 11:13:55 -08:00
kernel-dentry-operations.m4 Eliminate runtime function pointer mods in autotools checks 2013-03-04 08:49:17 -08:00
kernel-dirty-inode.m4 Eliminate runtime function pointer mods in autotools checks 2013-03-04 08:49:17 -08:00
kernel-discard-granularity.m4 Set zvol discard_granularity to the volblocksize. 2012-08-07 14:55:31 -07:00
kernel-elevator-change.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
kernel-encode-fh-inode.m4 Linux 3.5 compat, eops->encode_fh() takes inodes 2012-07-23 12:29:23 -07:00
kernel-evict-inode.m4 Fix build failures on PaX/GRSecurity patched kernels 2012-07-17 09:22:43 -07:00
kernel-fallocate.m4 Eliminate runtime function pointer mods in autotools checks 2013-03-04 08:49:17 -08:00
kernel-file-inode.m4 Linux 3.19 compat: file_inode was added 2015-02-10 11:24:51 -08:00
kernel-fmode-t.m4 Fix gcc configure warnings 2011-04-19 10:10:47 -07:00
kernel-follow-down-one.m4 Linux 3.18 compat: Snapshot auto-mounting 2015-08-31 13:54:39 -07:00
kernel-fsync.m4 Eliminate runtime function pointer mods in autotools checks 2013-03-04 08:49:17 -08:00
kernel-generic_io_acct.m4 Reintroduce IO accounting on zvols on Linux 3.19+ 2015-09-09 09:29:24 -07:00
kernel-get-disk-ro.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
kernel-get-gendisk.m4 When checking for symbol exports, try compiling. 2012-07-26 13:42:57 -07:00
kernel-get-link.m4 Linux 4.5 compat: get_link() / put_link() 2016-01-29 09:52:13 -08:00
kernel-insert-inode-locked.m4 When checking for symbol exports, try compiling. 2012-07-26 13:42:57 -07:00
kernel-invalidate-bdev-args.m4 Fix gcc configure warnings 2011-04-19 10:10:47 -07:00
kernel-is_owner_or_cap.m4 Refactor inode_owner_or_capable() autotools check 2014-05-01 10:06:49 -07:00
kernel-kmap-atomic-args.m4 Add compatibility layer for {kmap,kunmap}_atomic 2015-08-24 10:13:25 -07:00
kernel-kobj-name-len.m4 Fix gcc configure warnings 2011-04-19 10:10:47 -07:00
kernel-lookup-bdev.m4 Fix lookup_bdev() on Ubuntu 2017-02-03 10:24:34 -08:00
kernel-lookup-nameidata.m4 Linux 4.2 compat: follow_link() / put_link() 2015-07-17 09:18:16 -07:00
kernel-lseek-execute.m4 Add SEEK_DATA/SEEK_HOLE to lseek()/llseek() 2013-07-02 09:24:43 -07:00
kernel-mk-request-fn.m4 Linux 4.4 compat: make_request_fn returns blk_qc_t 2015-12-04 14:58:32 -08:00
kernel-mkdir-umode-t.m4 Eliminate runtime function pointer mods in autotools checks 2013-03-04 08:49:17 -08:00
kernel-mount-nodev.m4 When checking for symbol exports, try compiling. 2012-07-26 13:42:57 -07:00
kernel-open-bdev-exclusive.m4 When checking for symbol exports, try compiling. 2012-07-26 13:42:57 -07:00
kernel-put-link.m4 Linux 4.5 compat: get_link() / put_link() 2016-01-29 09:52:13 -08:00
kernel-rename.m4 Linux 4.9 compat: iops->rename() wants flags 2017-02-03 10:23:57 -08:00
kernel-security-inode-init.m4 Use -Werror for all kernel configure tests. 2013-02-24 10:20:28 -08:00
kernel-set-nlink.m4 Linux 3.2 compat: set_nlink() 2011-12-16 20:02:52 -08:00
kernel-setattr-prepare.m4 Linux 4.9 compat: inode_change_ok() renamed setattr_prepare() 2017-02-03 10:24:06 -08:00
kernel-sget-args.m4 Linux 3.6 compat, sget() 2012-10-14 13:06:48 -07:00
kernel-show-options.m4 Fix NULL pointer dereference on PaX/GRSecurity patched Linux 3.3 and later kernels 2012-07-20 12:31:45 -07:00
kernel-shrink.m4 3.12 compat, NUMA-aware per-superblock shrinker 2015-06-17 10:43:13 -07:00
kernel-submit_bio.m4 Linux 4.8 compat: submit_bio() 2016-09-09 13:21:09 -07:00
kernel-truncate-range.m4 Linux 3.5 compat, iops->truncate_range() removed 2012-07-23 12:29:32 -07:00
kernel-truncate-setsize.m4 When checking for symbol exports, try compiling. 2012-07-26 13:42:57 -07:00
kernel-vfs-iterate.m4 Linux 4.7 compat: use iterate_shared for concurrent readdir 2016-09-05 16:07:08 -07:00
kernel-vfs-rw-iterate.m4 Linux 4.1 compat: use read_iter() / write_iter() 2015-06-18 12:06:59 -07:00
kernel-xattr-handler.m4 Linux 4.9 compat: remove iops->{set,get,remove}xattr 2017-02-03 10:24:00 -08:00
kernel.m4 Fix sync behavior for disk vdevs 2017-02-03 10:24:54 -08:00
mount-helper.m4 The mount helper mount.zfs MUST be in /sbin (not '$sbindir'). 2015-05-18 16:54:36 -07:00
rpm.am Support parallel build trees (VPATH builds) 2015-07-17 13:42:51 -07:00
suppressed-warnings.txt Suppress packaging warning 2011-11-08 11:32:04 -08:00
tgz.am Refresh RPM packaging 2013-03-18 15:33:17 -07:00
user-arch.m4 Add build system 2010-08-31 13:41:27 -07:00
user-dracut.m4 Accept udev and dracut paths specified by ./configure 2014-06-11 16:32:57 -07:00
user-frame-larger-than.m4 config: compile test rather than run test 2014-03-20 12:11:57 -07:00
user-libblkid.m4 Fix libblkid support 2013-10-10 16:56:51 -07:00
user-libuuid.m4 Add build system 2010-08-31 13:41:27 -07:00
user-runstatedir.m4 Add defs for makefile installation dir vars 2014-03-31 16:11:13 -07:00
user-systemd.m4 Make systemd-modules-load.service file directory configurable 2014-10-28 09:41:14 -07:00
user-sysvinit.m4 Add systemd unit files for ZFS startup 2014-02-05 12:25:30 -08:00
user-udev.m4 Accept udev and dracut paths specified by ./configure 2014-06-11 16:32:57 -07:00
user-zlib.m4 Add build system 2010-08-31 13:41:27 -07:00
user.m4 Make directory into which mount.zfs is installed configurable 2014-10-28 09:40:59 -07:00
zfs-build.m4 Disable gcc bool-compare warning 2015-07-13 12:55:26 -07:00
zfs-meta.m4 Restrict release number to META version 2014-05-29 19:31:50 -07:00