zfs/config
Brian Behlendorf 278bee9319 Linux 3.18 compat: Snapshot auto-mounting
Re-factor the .zfs/snapshot auto-mouting code to take in to account
changes made to the upstream kernels.  And to lay the groundwork for
enabling access to .zfs snapshots via NFS clients.  This patch makes
the following core improvements.

* All actively auto-mounted snapshots are now tracked in two global
trees which are indexed by snapshot name and objset id respectively.
This allows for fast lookups of any auto-mounted snapshot regardless
without needing access to the parent dataset.

* Snapshot entries are added to the tree in zfsctl_snapshot_mount().
However, they are now removed from the tree in the context of the
unmount process.  This eliminates the need complicated error logic
in zfsctl_snapshot_unmount() to handle unmount failures.

* References are now taken on the snapshot entries in the tree to
ensure they always remain valid while a task is outstanding.

* The MNT_SHRINKABLE flag is set on the snapshot vfsmount_t right
after the auto-mount succeeds.  This allows to kernel to unmount
idle auto-mounted snapshots if needed removing the need for the
zfsctl_unmount_snapshots() function.

* Snapshots in active use will not be automatically unmounted.  As
long as at least one dentry is revalidated every zfs_expire_snapshot/2
seconds the auto-unmount expiration timer will be extended.

* Commit torvalds/linux@bafc9b7 caused snapshots auto-mounted by ZFS
to be immediately unmounted when the dentry was revalidated.  This
was a consequence of ZFS invaliding all snapdir dentries to ensure that
negative dentries didn't mask new snapshots.  This patch modifies the
behavior such that only negative dentries are invalidated.  This solves
the issue and may result in a performance improvement.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3589
Closes #3344
Closes #3295
Closes #3257
Closes #3243
Closes #3030
Closes #2841
2015-08-31 13:54:39 -07:00
..
.gitignore Add config/compile to config/.gitignore 2014-10-31 16:25:34 -07:00
Rules.am Disable gcc bool-compare warning 2015-07-13 12:55:26 -07:00
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 Make license compatibility checks consistent 2014-10-17 14:58:38 -07:00
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 Eliminate runtime function pointer mods in autotools checks 2013-03-04 08:49:17 -08:00
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-rw-syncio.m4 Fix gcc configure warnings 2011-04-19 10:10:47 -07:00
kernel-blk-end-request.m4 Make license compatibility checks consistent 2014-10-17 14:58:38 -07:00
kernel-blk-fetch-request.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
kernel-blk-queue-discard.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
kernel-blk-queue-flush.m4 Make license compatibility checks consistent 2014-10-17 14:58:38 -07:00
kernel-blk-queue-io-opt.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
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-nonrot.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
kernel-blk-queue-physical-block-size.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
kernel-blk-requeue-request.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
kernel-blk-rq-bytes.m4 Make license compatibility checks consistent 2014-10-17 14:58:38 -07:00
kernel-blk-rq-pos.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -08:00
kernel-blk-rq-sectors.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -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-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-follow-link-nameidata.m4 Linux 4.2 compat: follow_link() / put_link() 2015-07-17 09:18:16 -07:00
kernel-fsync.m4 Eliminate runtime function pointer mods in autotools checks 2013-03-04 08:49:17 -08:00
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-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 Linux 2.6.26 compat, lookup_bdev() 2013-01-28 15:35:00 -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-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-nameidata.m4 Linux 4.2 compat: follow_link() / put_link() 2015-07-17 09:18:16 -07:00
kernel-rq-for-each_segment.m4 Linux 3.14 compat: rq_for_each_segment in dmu_req_copy 2014-04-10 14:28:51 -07:00
kernel-rq-is_sync.m4 Only use gcc -Wunused-but-set-variable when available 2013-01-10 16:09:39 -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-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-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 3.11 compat: fops->iterate() 2013-08-15 16:19:07 -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 Refactor inode_owner_or_capable() autotools check 2014-05-01 10:06:49 -07:00
kernel.m4 Linux 3.18 compat: Snapshot auto-mounting 2015-08-31 13:54:39 -07:00
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