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* Fix typosAndrea Gelmini2020-06-091-1/+1
| | | | | | | | | Correct various typos in the comments and tests. Reviewed-by: Ryan Moeller <[email protected]> Reviewed-by: Matthew Ahrens <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Andrea Gelmini <[email protected]> Closes #10423
* Move platform specific parts of zfs_znode.h to platform codeMatthew Macy2019-11-061-137/+12
| | | | | | | | | Some of the znode fields are different and functions consuming an inode don't exist on FreeBSD. Reviewed-by: Brian Behlendorf <[email protected]> Reviewed-by: Jorgen Lundman <[email protected]> Signed-off-by: Matt Macy <[email protected]> Closes #9536
* Prefix struct rangelockMatthew Macy2019-11-011-1/+1
| | | | | | | | | | A struct rangelock already exists on FreeBSD. Add a zfs_ prefix as per our convention to prevent any conflict with existing symbols. This change is a follow up to 2cc479d0. Reviewed-by: Matt Ahrens <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Matt Macy <[email protected]> Closes #9534
* Add inode accessors to common codeMatthew Macy2019-10-021-1/+9
| | | | | | Reviewed-by: Brian Behlendorf <[email protected]> Reviewed-by: Jorgen Lundman <[email protected]> Signed-off-by: Matt Macy <[email protected]> Closes #9389
* Fix deadlock in 'zfs rollback'Tom Caputi2019-08-271-0/+1
| | | | | | | | | | | | | | | | | | | | Currently, the 'zfs rollback' code can end up deadlocked due to the way the kernel handles unreferenced inodes on a suspended fs. Essentially, the zfs_resume_fs() code path may cause zfs to spawn new threads as it reinstantiates the suspended fs's zil. When a new thread is spawned, the kernel may attempt to free memory for that thread by freeing some unreferenced inodes. If it happens to select inodes that are a a part of the suspended fs a deadlock will occur because freeing inodes requires holding the fs's z_teardown_inactive_lock which is still held from the suspend. This patch corrects this issue by adding an additional reference to all inodes that are still present when a suspend is initiated. This prevents them from being freed by the kernel for any reason. Reviewed-by: Alek Pinchuk <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Tom Caputi <[email protected]> Closes #9203
* Fix out-of-order ZIL txtype lost on hardlinked filesChunwei Chen2019-08-131-1/+1
| | | | | | | | | | | | | | | | We should only call zil_remove_async when an object is removed. However, in current implementation, it is called whenever TX_REMOVE is called. In the case of hardlinked file, every unlink will generate TX_REMOVE and causing operations to be dropped even when the object is not removed. We fix this by only calling zil_remove_async when the file is fully unlinked. Reviewed-by: George Wilson <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Reviewed-by: Prakash Surya <[email protected]> Signed-off-by: Chunwei Chen <[email protected]> Closes #8769 Closes #9061
* Change boolean-like uint8_t fields in znode_t to boolean_tTomohiro Kusumi2019-08-131-8/+8
| | | | | | | | | Given znode_t is an in-core structure, it's more readable to have them as boolean. Also co-locate existing boolean fields with them for space efficiency (expecting 8 booleans to be packed/aligned). Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Tomohiro Kusumi <[email protected]> Closes #9092
* Fix `zfs set atime|relatime=off|on` behavior on inherited datasetsTomohiro Kusumi2019-05-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | `zfs set atime|relatime=off|on` doesn't disable or enable the property on read for datasets whose property was inherited from parent, until a dataset is once unmounted and mounted again. (The properties start to work properly if a dataset is once unmounted and mounted again. The difference comes from regular mount process, e.g. via zpool import, uses mount options based on properties read from ondisk layout for each dataset, whereas `zfs set atime|relatime=off|on` just remounts a specified dataset.) -- # zpool create p1 <device> # zfs create p1/f1 # zfs set atime=off p1 # echo test > /p1/f1/test # sync # zfs list NAME USED AVAIL REFER MOUNTPOINT p1 176K 18.9G 25.5K /p1 p1/f1 26K 18.9G 26K /p1/f1 # zfs get atime NAME PROPERTY VALUE SOURCE p1 atime off local p1/f1 atime off inherited from p1 # stat /p1/f1/test | grep Access | tail -1 Access: 2019-04-26 23:32:33.741205192 +0900 # cat /p1/f1/test test # stat /p1/f1/test | grep Access | tail -1 Access: 2019-04-26 23:32:50.173231861 +0900 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ changed by read(2) -- The problem is that zfsvfs::z_atime which was probably intended to keep incore atime state just gets updated by a callback function of "atime" property change, atime_changed_cb(), and never used for anything else. Since now that all file read and atime update use a common function zpl_iter_read_common() -> file_accessed(), and whether to update atime via ->dirty_inode() is determined by atime_needs_update(), atime_needs_update() needs to return false once atime is turned off. It currently continues to return true on `zfs set atime=off`. Fix atime_changed_cb() by setting or dropping SB_NOATIME in VFS super block depending on a new atime value, so that atime_needs_update() works as expected after property change. The same problem applies to "relatime" except that a self contained relatime test is needed. This is because relatime_need_update() is based on a mount option flag MNT_RELATIME, which doesn't exist in datasets with inherited "relatime" property via `zfs set relatime=...`, hence it needs its own relatime test zfs_relatime_need_update(). Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Tomohiro Kusumi <[email protected]> Closes #8674 Closes #8675
* Linux does not HAVE_SMB_SHAREMatthew Ahrens2018-10-171-1/+0
| | | | | | | | | | Since Linux does not have an in-kernel SMB server, we don't need the code to manage it. Reviewed-by: Brian Behlendorf <[email protected]> Reviewed-by: George Melikov <[email protected]> Reviewed-by: Richard Elling <[email protected]> Signed-off-by: Matthew Ahrens <[email protected]> Closes #8032
* OpenZFS 9689 - zfs range lock code should not be zpl-specificMatt Ahrens2018-10-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ZFS range locking code in zfs_rlock.c/h depends on ZPL-specific data structures, specifically znode_t. However, it's also used by the ZVOL code, which uses a "dummy" znode_t to pass to the range locking code. We should clean this up so that the range locking code is generic and can be used equally by ZPL and ZVOL, and also can be used by future consumers that may need to run in userland (libzpool) as well as the kernel. Porting notes: * Added missing sys/avl.h include to sys/zfs_rlock.h. * Removed 'dbuf is within the locked range' ASSERTs from dmu_sync(). This was needed because ztest does not yet use a locked_range_t. * Removed "Approved by:" tag requirement from OpenZFS commit check to prevent needless warnings when integrating changes which has not been merged to illumos. * Reverted free_list range lock changes which were originally needed to defer the cv_destroy() which was called immediately after cv_broadcast(). With d2733258 this should be safe but if not we may need to reintroduce this logic. * Reverts: The following two commits were reverted and squashed in to this change in order to make it easier to apply OpenZFS 9689. - d88895a0, which removed the dummy znode from zvol_state - e3a07cd0, which updated ztest to use range locks * Preserved optimized rangelock comparison function. Preserved the rangelock free list. The cv_destroy() function will block waiting for all processes in cv_wait() to be scheduled and drop their reference. This is done to ensure it's safe to free the condition variable. However, blocking while holding the rl->rl_lock mutex can result in a deadlock on Linux. A free list is introduced to defer the cv_destroy() and kmem_free() until after the mutex is released. Authored by: Matthew Ahrens <[email protected]> Reviewed by: Brian Behlendorf <[email protected]> Reviewed by: Serapheim Dimitropoulos <[email protected]> Reviewed by: George Wilson <[email protected]> Reviewed by: Brad Lewis <[email protected]> Ported-by: Brian Behlendorf <[email protected]> OpenZFS-issue: https://illumos.org/issues/9689 OpenZFS-commit: https://github.com/openzfs/openzfs/pull/680 External-issue: DLPX-58662 Closes #7980
* Linux 4.19-rc3+ compat: Remove refcount_t compatTim Schumacher2018-09-261-1/+1
| | | | | | | | | | | | | | | torvalds/linux@59b57717f ("blkcg: delay blkg destruction until after writeback has finished") added a refcount_t to the blkcg structure. Due to the refcount_t compatibility code, zfs_refcount_t was used by mistake. Resolve this by removing the compatibility code and replacing the occurrences of refcount_t with zfs_refcount_t. Reviewed-by: Franz Pletz <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Tim Schumacher <[email protected]> Closes #7885 Closes #7932
* Add missing checks to zpl_xattr_* functionsJohn Gallagher2018-08-021-22/+29
| | | | | | | | | | | | | Linux specific zpl_* entry points, such as xattrs, must include the same unmounted and sa handle checks as the common zfs_ entry points. The additional ZPL_* wrappers are identical to their ZFS_ counterparts except the errno is negated since they are expected to be used at the zpl_ layer. Reviewed by: Matthew Ahrens <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: John Gallagher <[email protected]> Closes #5866 Closes #7761
* Linux 4.18 compat: inode timespec -> timespec64Brian Behlendorf2018-06-191-8/+25
| | | | | | | | | | | | | | | | | | | | | | | | Commit torvalds/linux@95582b0 changes the inode i_atime, i_mtime, and i_ctime members form timespec's to timespec64's to make them 2038 safe. As part of this change the current_time() function was also updated to return the timespec64 type. Resolve this issue by introducing a new inode_timespec_t type which is defined to match the timespec type used by the inode. It should be used when working with inode timestamps to ensure matching types. The timestruc_t type under Illumos was used in a similar fashion but was specified to always be a timespec_t. Rather than incorrectly define this type all timespec_t types have been replaced by the new inode_timespec_t type. Finally, the kernel and user space 'sys/time.h' headers were aligned with each other. They define as appropriate for the context several constants as macros and include static inline implementation of gethrestime(), gethrestime_sec(), and gethrtime(). Reviewed-by: Chunwei Chen <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #7643
* Update build system and packagingBrian Behlendorf2018-05-291-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Minimal changes required to integrate the SPL sources in to the ZFS repository build infrastructure and packaging. Build system and packaging: * Renamed SPL_* autoconf m4 macros to ZFS_*. * Removed redundant SPL_* autoconf m4 macros. * Updated the RPM spec files to remove SPL package dependency. * The zfs package obsoletes the spl package, and the zfs-kmod package obsoletes the spl-kmod package. * The zfs-kmod-devel* packages were updated to add compatibility symlinks under /usr/src/spl-x.y.z until all dependent packages can be updated. They will be removed in a future release. * Updated copy-builtin script for in-kernel builds. * Updated DKMS package to include the spl.ko. * Updated stale AUTHORS file to include all contributors. * Updated stale COPYRIGHT and included the SPL as an exception. * Renamed README.markdown to README.md * Renamed OPENSOLARIS.LICENSE to LICENSE. * Renamed DISCLAIMER to NOTICE. Required code changes: * Removed redundant HAVE_SPL macro. * Removed _BOOT from nvpairs since it doesn't apply for Linux. * Initial header cleanup (removal of empty headers, refactoring). * Remove SPL repository clone/build from zimport.sh. * Use of DEFINE_RATELIMIT_STATE and DEFINE_SPINLOCK removed due to build issues when forcing C99 compilation. * Replaced legacy ACCESS_ONCE with READ_ONCE. * Include needed headers for `current` and `EXPORT_SYMBOL`. Reviewed-by: Tony Hutter <[email protected]> Reviewed-by: Olaf Faaland <[email protected]> Reviewed-by: Matthew Ahrens <[email protected]> Reviewed-by: Pavel Zakharov <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> TEST_ZIMPORT_SKIP="yes" Closes #7556
* Project Quota on ZFSNasf-Fan2018-02-131-1/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Project quota is a new ZFS system space/object usage accounting and enforcement mechanism. Similar as user/group quota, project quota is another dimension of system quota. It bases on the new object attribute - project ID. Project ID is a numerical value to indicate to which project an object belongs. An object only can belong to one project though you (the object owner or privileged user) can change the object project ID via 'chattr -p' or 'zfs project [-s] -p' explicitly. The object also can inherit the project ID from its parent when created if the parent has the project inherit flag (that can be set via 'chattr +P' or 'zfs project -s [-p]'). By accounting the spaces/objects belong to the same project, we can know how many spaces/objects used by the project. And if we set the upper limit then we can control the spaces/objects that are consumed by such project. It is useful when multiple groups and users cooperate for the same project, or a user/group needs to participate in multiple projects. Support the following commands and functionalities: zfs set projectquota@project zfs set projectobjquota@project zfs get projectquota@project zfs get projectobjquota@project zfs get projectused@project zfs get projectobjused@project zfs projectspace zfs allow projectquota zfs allow projectobjquota zfs allow projectused zfs allow projectobjused zfs unallow projectquota zfs unallow projectobjquota zfs unallow projectused zfs unallow projectobjused chattr +/-P chattr -p project_id lsattr -p This patch also supports tree quota based on the project quota via "zfs project" commands set as following: zfs project [-d|-r] <file|directory ...> zfs project -C [-k] [-r] <file|directory ...> zfs project -c [-0] [-d|-r] [-p id] <file|directory ...> zfs project [-p id] [-r] [-s] <file|directory ...> For "df [-i] $DIR" command, if we set INHERIT (project ID) flag on the $DIR, then the proejct [obj]quota and [obj]used values for the $DIR's project ID will be shown as the total/free (avail) resource. Keep the same behavior as EXT4/XFS does. Reviewed-by: Andreas Dilger <[email protected]> Reviewed-by Ned Bass <[email protected]> Reviewed-by: Matthew Ahrens <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Fan Yong <[email protected]> TEST_ZIMPORT_POOLS="zol-0.6.1 zol-0.6.2 master" Change-Id: Ib4f0544602e03fb61fd46a849d7ba51a6005693c Closes #6290
* OpenZFS 8081 - Compiler warnings in zdbBrian Behlendorf2017-10-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix compiler warnings in zdb. With these changes, FreeBSD can compile zdb with all compiler warnings enabled save -Wunused-parameter. usr/src/cmd/zdb/zdb.c usr/src/cmd/zdb/zdb_il.c usr/src/uts/common/fs/zfs/sys/sa.h usr/src/uts/common/fs/zfs/sys/spa.h Fix numerous warnings, including: * const-correctness * shadowing global definitions * signed vs unsigned comparisons * missing prototypes, or missing static declarations * unused variables and functions * Unreadable array initializations * Missing struct initializers usr/src/cmd/zdb/zdb.h Add a header file to declare common symbols usr/src/lib/libzpool/common/sys/zfs_context.h usr/src/uts/common/fs/zfs/arc.c usr/src/uts/common/fs/zfs/dbuf.c usr/src/uts/common/fs/zfs/spa.c usr/src/uts/common/fs/zfs/txg.c Add a function prototype for zk_thread_create, and ensure that every callback supplied to this function actually matches the prototype. usr/src/cmd/ztest/ztest.c usr/src/uts/common/fs/zfs/sys/zil.h usr/src/uts/common/fs/zfs/zfs_replay.c usr/src/uts/common/fs/zfs/zvol.c Add a function prototype for zil_replay_func_t, and ensure that every function of this type actually matches the prototype. usr/src/uts/common/fs/zfs/sys/refcount.h Change FTAG so it discards any constness of __func__, necessary since existing APIs expect it passed as void *. Porting Notes: - Many of these fixes have already been applied to Linux. For consistency the OpenZFS version of a change was applied if the warning was addressed in an equivalent but different fashion. Reviewed by: Matthew Ahrens <[email protected]> Reviewed by: Prakash Surya <[email protected]> Authored by: Alan Somers <[email protected]> Approved by: Richard Lowe <[email protected]> Ported-by: Brian Behlendorf <[email protected]> OpenZFS-issue: https://www.illumos.org/issues/8081 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/843abe1b8a Closes #6787
* Rename zfs_sb_t -> zfsvfs_tBrian Behlendorf2017-03-101-13/+13
| | | | | | | | | | | The use of zfs_sb_t instead of zfsvfs_t results in unnecessary conflicts with the upstream source. Change all instances of zfs_sb_t to zfsvfs_t including updating the variables names. Whenever possible the code was updated to be consistent with hope it appears in the upstream OpenZFS source. Signed-off-by: Brian Behlendorf <[email protected]>
* OpenZFS 7301 - zpool export -f should be able to interrupt file freeingGeorge Melikov2017-01-271-0/+2
| | | | | | | | | | | | | | | Authored by: Alek Pinchuk <[email protected]> Reviewed by: Matthew Ahrens <[email protected]> Reviewed by: Sanjay Nadkarni <[email protected]> Reviewed by: Saso Kiselkov <[email protected]> Reviewed by: John Kennedy <[email protected]> Approved by: Gordon Ross <[email protected]> Reviewed-by: Tim Chase <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Ported-by: George Melikov <[email protected]> OpenZFS-issue: https://www.illumos.org/issues/7301 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/eb72182 Closes #5680
* Fix unlinked file cannot do xattr operationsChunwei Chen2016-11-041-0/+1
| | | | | | | | | | | | | | | | | Currently, doing things like fsetxattr(2) on an unlinked file will result in ENODATA. There's two places that cause this: zfs_dirent_lock and zfs_zget. The fix in zfs_dirent_lock is pretty straightforward. In zfs_zget though, we need it to not return error when the zp is unlinked. This is a pretty big change in behavior, but skimming through all the callers, I don't think this change would cause any problem. Also there's nothing preventing z_unlinked from being set after the z_lock mutex is dropped before but before zfs_zget returns anyway. The rest of the stuff is to make sure we don't log xattr stuff when owner is unlinked. Signed-off-by: Chunwei Chen <[email protected]>
* Remove znode's z_uid/z_gid memberNikolay Borisov2016-07-251-2/+0
| | | | | | | | | | | | | | | Remove duplicate z_uid/z_gid member which are also held in the generic vfs inode struct. This is done by first removing the members from struct znode and then using the KUID_TO_SUID/KGID_TO_SGID macros to access the respective member from struct inode. In cases where the uid/gids are being marshalled from/to disk, use the newly introduced zfs_(uid|gid)_(read|write) functions to properly save the uids rather than the internal kernel representation. Signed-off-by: Nikolay Borisov <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #4685 Issue #227
* Use native inode->i_nlink instead of znode->z_linksChris Dunlop2016-07-141-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | A mostly mechanical change, taking into account i_nlink is 32 bits vs ZFS's 64 bit on-disk link count. We revert "xattr dir doesn't get purged during iput" (ddae16a) as this is a more Linux-integrated fix for the same issue. In addition, setting the initial link count on a new node has been changed from setting one less than required in zfs_mknode() then incrementing to the correct count in zfs_link_create() (which was somewhat bizarre in the first place), to setting the correct count in zfs_mknode() and not incrementing it in zfs_link_create(). This both means we no longer set the link count in sa_bulk_update() twice (once for the initial incorrect count then again for the correct count), as well as adhering to the Linux requirement of not incrementing a zero link count without I_LINKABLE (see linux commit f4e0c30c). Signed-off-by: Chris Dunlop <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Chunwei Chen <[email protected]> Closes #4838 Issue #227
* Kill zp->z_xattr_parent to prevent pinningChunwei Chen2016-07-121-1/+0
| | | | | | | | | | | | | | | | | | | | zp->z_xattr_parent will pin the parent. This will cause huge issue when unlink a file with xattr. Because the unlinked file is pinned, it will never get purged immediately. And because of that, the xattr stuff will never be marked as unlinked. So the whole unlinked stuff will stay there until shrink cache or umount. This change partially reverts e89260a. This is safe because only the zp->z_xattr_parent optimization is removed, zpl_xattr_security_init() is still called from the zpl outside the inode lock. Signed-off-by: Chunwei Chen <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Chris Dunlop <[email protected]> Issue #4359 Issue #3508 Issue #4413 Issue #4827
* OpenZFS 6314 - buffer overflow in dsl_dataset_nameIgor Kozhukhov2016-06-281-12/+1
| | | | | | | | | | | Reviewed by: George Wilson <[email protected]> Reviewed by: Prakash Surya <[email protected]> Reviewed by: Igor Kozhukhov <[email protected]> Approved by: Dan McDonald <[email protected]> Ported-by: Brian Behlendorf <[email protected]> OpenZFS-issue: https://www.illumos.org/issues/6314 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/d6160ee
* Implement large_dnode pool featureNed Bass2016-06-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Justification ------------- This feature adds support for variable length dnodes. Our motivation is to eliminate the overhead associated with using spill blocks. Spill blocks are used to store system attribute data (i.e. file metadata) that does not fit in the dnode's bonus buffer. By allowing a larger bonus buffer area the use of a spill block can be avoided. Spill blocks potentially incur an additional read I/O for every dnode in a dnode block. As a worst case example, reading 32 dnodes from a 16k dnode block and all of the spill blocks could issue 33 separate reads. Now suppose those dnodes have size 1024 and therefore don't need spill blocks. Then the worst case number of blocks read is reduced to from 33 to two--one per dnode block. In practice spill blocks may tend to be co-located on disk with the dnode blocks so the reduction in I/O would not be this drastic. In a badly fragmented pool, however, the improvement could be significant. ZFS-on-Linux systems that make heavy use of extended attributes would benefit from this feature. In particular, ZFS-on-Linux supports the xattr=sa dataset property which allows file extended attribute data to be stored in the dnode bonus buffer as an alternative to the traditional directory-based format. Workloads such as SELinux and the Lustre distributed filesystem often store enough xattr data to force spill bocks when xattr=sa is in effect. Large dnodes may therefore provide a performance benefit to such systems. Other use cases that may benefit from this feature include files with large ACLs and symbolic links with long target names. Furthermore, this feature may be desirable on other platforms in case future applications or features are developed that could make use of a larger bonus buffer area. Implementation -------------- The size of a dnode may be a multiple of 512 bytes up to the size of a dnode block (currently 16384 bytes). A dn_extra_slots field was added to the current on-disk dnode_phys_t structure to describe the size of the physical dnode on disk. The 8 bits for this field were taken from the zero filled dn_pad2 field. The field represents how many "extra" dnode_phys_t slots a dnode consumes in its dnode block. This convention results in a value of 0 for 512 byte dnodes which preserves on-disk format compatibility with older software. Similarly, the in-memory dnode_t structure has a new dn_num_slots field to represent the total number of dnode_phys_t slots consumed on disk. Thus dn->dn_num_slots is 1 greater than the corresponding dnp->dn_extra_slots. This difference in convention was adopted because, unlike on-disk structures, backward compatibility is not a concern for in-memory objects, so we used a more natural way to represent size for a dnode_t. The default size for newly created dnodes is determined by the value of a new "dnodesize" dataset property. By default the property is set to "legacy" which is compatible with older software. Setting the property to "auto" will allow the filesystem to choose the most suitable dnode size. Currently this just sets the default dnode size to 1k, but future code improvements could dynamically choose a size based on observed workload patterns. Dnodes of varying sizes can coexist within the same dataset and even within the same dnode block. For example, to enable automatically-sized dnodes, run # zfs set dnodesize=auto tank/fish The user can also specify literal values for the dnodesize property. These are currently limited to powers of two from 1k to 16k. The power-of-2 limitation is only for simplicity of the user interface. Internally the implementation can handle any multiple of 512 up to 16k, and consumers of the DMU API can specify any legal dnode value. The size of a new dnode is determined at object allocation time and stored as a new field in the znode in-memory structure. New DMU interfaces are added to allow the consumer to specify the dnode size that a newly allocated object should use. Existing interfaces are unchanged to avoid having to update every call site and to preserve compatibility with external consumers such as Lustre. The new interfaces names are given below. The versions of these functions that don't take a dnodesize parameter now just call the _dnsize() versions with a dnodesize of 0, which means use the legacy dnode size. New DMU interfaces: dmu_object_alloc_dnsize() dmu_object_claim_dnsize() dmu_object_reclaim_dnsize() New ZAP interfaces: zap_create_dnsize() zap_create_norm_dnsize() zap_create_flags_dnsize() zap_create_claim_norm_dnsize() zap_create_link_dnsize() The constant DN_MAX_BONUSLEN is renamed to DN_OLD_MAX_BONUSLEN. The spa_maxdnodesize() function should be used to determine the maximum bonus length for a pool. These are a few noteworthy changes to key functions: * The prototype for dnode_hold_impl() now takes a "slots" parameter. When the DNODE_MUST_BE_FREE flag is set, this parameter is used to ensure the hole at the specified object offset is large enough to hold the dnode being created. The slots parameter is also used to ensure a dnode does not span multiple dnode blocks. In both of these cases, if a failure occurs, ENOSPC is returned. Keep in mind, these failure cases are only possible when using DNODE_MUST_BE_FREE. If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0. dnode_hold_impl() will check if the requested dnode is already consumed as an extra dnode slot by an large dnode, in which case it returns ENOENT. * The function dmu_object_alloc() advances to the next dnode block if dnode_hold_impl() returns an error for a requested object. This is because the beginning of the next dnode block is the only location it can safely assume to either be a hole or a valid starting point for a dnode. * dnode_next_offset_level() and other functions that iterate through dnode blocks may no longer use a simple array indexing scheme. These now use the current dnode's dn_num_slots field to advance to the next dnode in the block. This is to ensure we properly skip the current dnode's bonus area and don't interpret it as a valid dnode. zdb --- The zdb command was updated to display a dnode's size under the "dnsize" column when the object is dumped. For ZIL create log records, zdb will now display the slot count for the object. ztest ----- Ztest chooses a random dnodesize for every newly created object. The random distribution is more heavily weighted toward small dnodes to better simulate real-world datasets. Unused bonus buffer space is filled with non-zero values computed from the object number, dataset id, offset, and generation number. This helps ensure that the dnode traversal code properly skips the interior regions of large dnodes, and that these interior regions are not overwritten by data belonging to other dnodes. A new test visits each object in a dataset. It verifies that the actual dnode size matches what was stored in the ztest block tag when it was created. It also verifies that the unused bonus buffer space is filled with the expected data patterns. ZFS Test Suite -------------- Added six new large dnode-specific tests, and integrated the dnodesize property into existing tests for zfs allow and send/recv. Send/Receive ------------ ZFS send streams for datasets containing large dnodes cannot be received on pools that don't support the large_dnode feature. A send stream with large dnodes sets a DMU_BACKUP_FEATURE_LARGE_DNODE flag which will be unrecognized by an incompatible receiving pool so that the zfs receive will fail gracefully. While not implemented here, it may be possible to generate a backward-compatible send stream from a dataset containing large dnodes. The implementation may be tricky, however, because the send object record for a large dnode would need to be resized to a 512 byte dnode, possibly kicking in a spill block in the process. This means we would need to construct a new SA layout and possibly register it in the SA layout object. The SA layout is normally just sent as an ordinary object record. But if we are constructing new layouts while generating the send stream we'd have to build the SA layout object dynamically and send it at the end of the stream. For sending and receiving between pools that do support large dnodes, the drr_object send record type is extended with a new field to store the dnode slot count. This field was repurposed from unused padding in the structure. ZIL Replay ---------- The dnode slot count is stored in the uppermost 8 bits of the lr_foid field. The bits were unused as the object id is currently capped at 48 bits. Resizing Dnodes --------------- It should be possible to resize a dnode when it is dirtied if the current dnodesize dataset property differs from the dnode's size, but this functionality is not currently implemented. Clearly a dnode can only grow if there are sufficient contiguous unused slots in the dnode block, but it should always be possible to shrink a dnode. Growing dnodes may be useful to reduce fragmentation in a pool with many spill blocks in use. Shrinking dnodes may be useful to allow sending a dataset to a pool that doesn't support the large_dnode feature. Feature Reference Counting -------------------------- The reference count for the large_dnode pool feature tracks the number of datasets that have ever contained a dnode of size larger than 512 bytes. The first time a large dnode is created in a dataset the dataset is converted to an extensible dataset. This is a one-way operation and the only way to decrement the feature count is to destroy the dataset, even if the dataset no longer contains any large dnodes. The complexity of reference counting on a per-dnode basis was too high, so we chose to track it on a per-dataset basis similarly to the large_block feature. Signed-off-by: Ned Bass <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3542
* Kill znode->z_gen fieldNikolay Borisov2016-05-191-1/+0
| | | | | | | | | | | | This field is a duplicate of the inode->i_generation, so just kill it. Signed-off-by: Nikolay Borisov <[email protected]> Signed-off-by: Chunwei Chen <[email protected]> Signed-off-by: Tim Chase <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #4538 Closes #4654
* Remove dummy znode from zvol_stateChunwei Chen2016-05-171-3/+2
| | | | | | | | | | | | | | | | | | | | | | struct zvol_state contains a dummy znode, which is around 1KB on x64, only for zfs_range_lock. But in reality, other than z_range_lock and z_range_avl, zfs_range_lock only need znode on regular file, which means we add 1KB on a structure and gain nothing. In this patch, we remove the dummy znode for zvol_state. In order to do that, we also need to refactor zfs_range_lock a bit. We move z_range_lock and z_range_avl pair out of znode_t to form zfs_rlock_t. This new struct replaces znode_t as the main handle inside the range lock functions. We also add pointers to z_size, z_blksz, and z_max_blksz so range lock code doesn't depend on znode_t. This allows non-ZPL consumers like Lustre to use the range locks with their equivalent znode_t structure. Signed-off-by: Chunwei Chen <[email protected]> Signed-off-by: Boris Protopopov <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #4510
* Revert "Kill znode->z_gen field"Brian Behlendorf2016-05-121-0/+1
| | | | | | | | | | This reverts commit 4cd77889b684fd0dd1a0a995b692dda3db76a9ac. The i_generation field in the inode is 32-bit and the SA code expects 64-bit fixed values. Revert this optimization for now until this is cleanly addressed. Signed-off-by: Brian Behlendorf <[email protected]> Issue #4538
* Kill znode->z_gen fieldNikolay Borisov2016-05-021-1/+0
| | | | | | | | This field is a duplicate of the inode->i_generation, so just kill it Signed-off-by: Nikolay Borisov <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #4538
* Fix atime handling and relatimeChunwei Chen2016-04-051-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The problem for atime: We have 3 places for atime: inode->i_atime, znode->z_atime and SA. And its handling is a mess. A huge part of mess regarding atime comes from zfs_tstamp_update_setup, zfs_inode_update, and zfs_getattr, which behave inconsistently with those three values. zfs_tstamp_update_setup clears z_atime_dirty unconditionally as long as you don't pass ATTR_ATIME. Which means every write(2) operation which only updates ctime and mtime will cause atime changes to not be written to disk. Also zfs_inode_update from write(2) will replace inode->i_atime with what's inside SA(stale). But doesn't touch z_atime. So after read(2) and write(2). You'll have i_atime(stale), z_atime(new), SA(stale) and z_atime_dirty=0. Now, if you do stat(2), zfs_getattr will actually replace i_atime with what's inside, z_atime. So you will have now you'll have i_atime(new), z_atime(new), SA(stale) and z_atime_dirty=0. These will all gone after umount. And you'll leave with a stale atime. The problem for relatime: We do have a relatime config inside ZFS dataset, but how it should interact with the mount flag MS_RELATIME is not well defined. It seems it wanted relatime mount option to override the dataset config by showing it as temporary in `zfs get`. But at the same time, `zfs set relatime=on|off` would also seems to want to override the mount option. Not to mention that MS_RELATIME flag is actually never passed into ZFS, so it never really worked. How Linux handles atime: The Linux kernel actually handles atime completely in VFS, except for writing it to disk. So if we remove the atime handling in ZFS, things would just work, no matter it's strictatime, relatime, noatime, or even O_NOATIME. And whenever VFS updates the i_atime, it will notify the underlying filesystem via sb->dirty_inode(). And also there's one thing to note about atime flags like MS_RELATIME and other flags like MS_NODEV, etc. They are mount point flags rather than filesystem(sb) flags. Since native linux filesystem can be mounted at multiple places at the same time, they can all have different atime settings. So these flags are never passed down to filesystem drivers. What this patch tries to do: We remove znode->z_atime, since we won't gain anything from it. We remove most of the atime handling and leave it to VFS. The only thing we do with atime is to write it when dirty_inode() or setattr() is called. We also add file_accessed() in zpl_read() since it's not provided in vfs_read(). After this patch, only the MS_RELATIME flag will have effect. The setting in dataset won't do anything. We will make zfstuil to mount ZFS with MS_RELATIME set according to the setting in dataset in future patch. Signed-off-by: Chunwei Chen <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #4482
* Fix zsb->z_hold_mtx deadlockBrian Behlendorf2016-01-151-15/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The zfs_znode_hold_enter() / zfs_znode_hold_exit() functions are used to serialize access to a znode and its SA buffer while the object is being created or destroyed. This kind of locking would normally reside in the znode itself but in this case that's impossible because the znode and SA buffer may not yet exist. Therefore the locking is handled externally with an array of mutexs and AVLs trees which contain per-object locks. In zfs_znode_hold_enter() a per-object lock is created as needed, inserted in to the correct AVL tree and finally the per-object lock is held. In zfs_znode_hold_exit() the process is reversed. The per-object lock is released, removed from the AVL tree and destroyed if there are no waiters. This scheme has two important properties: 1) No memory allocations are performed while holding one of the z_hold_locks. This ensures evict(), which can be called from direct memory reclaim, will never block waiting on a z_hold_locks which just happens to have hashed to the same index. 2) All locks used to serialize access to an object are per-object and never shared. This minimizes lock contention without creating a large number of dedicated locks. On the downside it does require znode_lock_t structures to be frequently allocated and freed. However, because these are backed by a kmem cache and very short lived this cost is minimal. Signed-off-by: Brian Behlendorf <[email protected]> Issue #4106
* Add zfs_object_mutex_size module optionBrian Behlendorf2016-01-151-2/+8
| | | | | | | | | | | Add a zfs_object_mutex_size module option to facilitate resizing the the per-dataset znode mutex array. Increasing this value may help make the deadlock described in #4106 less common, but this is not a proper fix. This patch is primarily to aid debugging and analysis. Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Tim Chase <[email protected]> Issue #4106
* Illumos 5008 - lock contention (rrw_exit) while running a read only loadAlexander Motin2015-07-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | 5008 lock contention (rrw_exit) while running a read only load Reviewed by: Matthew Ahrens <[email protected]> Reviewed by: George Wilson <[email protected]> Reviewed by: Alex Reece <[email protected]> Reviewed by: Christopher Siden <[email protected]> Reviewed by: Richard Yao <[email protected]> Reviewed by: Saso Kiselkov <[email protected]> Approved by: Garrett D'Amore <[email protected]> Porting notes: This patch ported perfectly cleanly to ZoL. During testing 100% cached small-block reads, extreme contention was noticed on rrl->rr_lock from rrw_exit() due to the frequent entering and leaving ZPL. Illumos picked up this patch from FreeBSD and it also helps under Linux. On a 1-minute 4K cached read test with 10 fio processes pinned to a single socket on a 4-socket (10 thread per socket) NUMA system, contentions on rrl->rr_lock were reduced from 508799 to 43085. Ported-by: Tim Chase <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3555
* Illumos 5027 - zfs large block supportMatthew Ahrens2015-05-111-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 5027 zfs large block support Reviewed by: Alek Pinchuk <[email protected]> Reviewed by: George Wilson <[email protected]> Reviewed by: Josef 'Jeff' Sipek <[email protected]> Reviewed by: Richard Elling <[email protected]> Reviewed by: Saso Kiselkov <[email protected]> Reviewed by: Brian Behlendorf <[email protected]> Approved by: Dan McDonald <[email protected]> References: https://www.illumos.org/issues/5027 https://github.com/illumos/illumos-gate/commit/b515258 Porting Notes: * Included in this patch is a tiny ISP2() cleanup in zio_init() from Illumos 5255. * Unlike the upstream Illumos commit this patch does not impose an arbitrary 128K block size limit on volumes. Volumes, like filesystems, are limited by the zfs_max_recordsize=1M module option. * By default the maximum record size is limited to 1M by the module option zfs_max_recordsize. This value may be safely increased up to 16M which is the largest block size supported by the on-disk format. At the moment, 1M blocks clearly offer a significant performance improvement but the benefits of going beyond this for the majority of workloads are less clear. * The illumos version of this patch increased DMU_MAX_ACCESS to 32M. This was determined not to be large enough when using 16M blocks because the zfs_make_xattrdir() function will fail (EFBIG) when assigning a TX. This was immediately observed under Linux because all newly created files must have a security xattr created and that was failing. Therefore, we've set DMU_MAX_ACCESS to 64M. * On 32-bit platforms a hard limit of 1M is set for blocks due to the limited virtual address space. We should be able to relax this one the ABD patches are merged. Ported-by: Brian Behlendorf <[email protected]> Closes #354
* Fix kernel panic due to tsd_exit in ZFS_EXIT(zsb)Chunwei Chen2015-04-241-1/+0
| | | | | | | | | | | | | | | | | | | | | | The following panic would occur under certain heavy load: [ 4692.202686] Kernel panic - not syncing: thread ffff8800c4f5dd60 terminating with rrw lock ffff8800da1b9c40 held [ 4692.228053] CPU: 1 PID: 6250 Comm: mmap_deadlock Tainted: P OE 3.18.10 #7 The culprit is that ZFS_EXIT(zsb) would call tsd_exit() every time, which would purge all tsd data for the thread. However, ZFS_ENTER is designed to be reentrant, so we cannot allow ZFS_EXIT to blindly purge tsd data. Instead, we rely on the new behavior of tsd_set. When NULL is passed as the new value to tsd_set, it will automatically remove the tsd entry specified the the key for the current thread. rrw_tsd_key and zfs_allow_log_key already calls tsd_set(key, NULL) when they're done. The zfs_fsyncer_key relied on ZFS_EXIT(zsb) to call tsd_exit() to do clean up. Now we explicitly call tsd_set(key, NULL) on them. Signed-off-by: Chunwei Chen <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3247
* Fix zil_commit() NULL dereferenceBrian Behlendorf2014-07-171-0/+1
| | | | | | | | | | | | Update the current code to ensure inodes are never dirtied if they are part of a read-only file system or snapshot. If they do somehow get dirtied an attempt will make made to write them to disk. In the case of snapshots, which don't have a ZIL, this will result in a NULL dereference in zil_commit(). Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #2405
* Use local variable to read zp->z_modeBrian Behlendorf2014-01-091-1/+1
| | | | | | | | | | | | | | | | | | When accessing the zp->z_mode through the SA bulk interface we expect that 64-bits are available to hold the result. However, on 32-bit platforms mode_t will only be 32-bits so we cannot pass it to SA_ADD_BULK_ATTR(). Instead a local uint64_t variable must be used and the result assigned to zp->z_mode. This went unnoticed on 32-bit little endian platforms because the bytes happen to end up in the correct 32-bits. But on big endian platforms like Sparc the zp->z_mode will always end up set to zero. Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Ned Bass <[email protected]> Signed-off-by: marku89 <[email protected]> Issue #1700
* cstyle: Resolve C style issuesMichael Kjorling2013-12-181-2/+2
| | | | | | | | | | | | | | | | | | The vast majority of these changes are in Linux specific code. They are the result of not having an automated style checker to validate the code when it was originally written. Others were caused when the common code was slightly adjusted for Linux. This patch contains no functional changes. It only refreshes the code to conform to style guide. Everyone submitting patches for inclusion upstream should now run 'make checkstyle' and resolve any warning prior to opening a pull request. The automated builders have been updated to fail a build if when 'make checkstyle' detects an issue. Signed-off-by: Brian Behlendorf <[email protected]> Closes #1821
* Only commit the ZIL once in zpl_writepages() (msync() case).Etienne Dechamps2013-11-231-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, using msync() results in the following code path: sys_msync -> zpl_fsync -> filemap_write_and_wait_range -> zpl_writepages -> write_cache_pages -> zpl_putpage In such a code path, zil_commit() is called as part of zpl_putpage(). This means that for each page, the write is handed to the DMU, the ZIL is committed, and only then do we move on to the next page. As one might imagine, this results in atrocious performance where there is a large number of pages to write: instead of committing a batch of N writes, we do N commits containing one page each. In some extreme cases this can result in msync() being ~700 times slower than it should be, as well as very inefficient use of ZIL resources. This patch fixes this issue by making sure that the requested writes are batched and then committed only once. Unfortunately, the implementation is somewhat non-trivial because there is no way to run write_cache_pages in SYNC mode (so that we get all pages) without making it wait on the writeback tag for each page. The solution implemented here is composed of two parts: - I added a new callback system to the ZIL, which allows the caller to be notified when its ITX gets written to stable storage. One nice thing is that the callback is called not only in zil_commit() but in zil_sync() as well, which means that the caller doesn't have to care whether the write ended up in the ZIL or the DMU: it will get notified as soon as it's safe, period. This is an improvement over dmu_tx_callback_register() that was used previously, which only supports DMU writes. The rationale for this change is to allow zpl_putpage() to be notified when a ZIL commit is completed without having to block on zil_commit() itself. - zpl_writepages() now calls write_cache_pages in non-SYNC mode, which will prevent (1) write_cache_pages from blocking, and (2) zpl_putpage from issuing ZIL commits. zpl_writepages() will issue the commit itself instead of relying on zpl_putpage() to do it, thus nicely batching the writes. Note, however, that we still have to call write_cache_pages() again in SYNC mode because there is an edge case documented in the implementation of write_cache_pages() whereas it will not give us all dirty pages when running in non-SYNC mode. Thus we need to run it at least once in SYNC mode to make sure we honor persistency guarantees. This only happens when the pages are modified at the same time msync() is running, which should be rare. In most cases there won't be any additional pages and this second call will do nothing. Note that this change also fixes a bug related to #907 whereas calling msync() on pages that were already handed over to the DMU in a previous writepages() call would make msync() block until the next TXG sync instead of returning as soon as the ZIL commit is complete. The new callback system fixes that problem. Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #1849 Closes #907
* Illumos #3742Will Andrews2013-11-041-9/+7
| | | | | | | | | | | | | | | | | | | | | 3742 zfs comments need cleaner, more consistent style Reviewed by: Matthew Ahrens <[email protected]> Reviewed by: George Wilson <[email protected]> Reviewed by: Eric Schrock <[email protected]> Approved by: Christopher Siden <[email protected]> References: https://www.illumos.org/issues/3742 illumos/illumos-gate@f7170741490edba9d1d9c697c177c887172bc741 Ported-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #1775 Porting notes: 1. The change to zfs_vfsops.c was dropped because it involves zfs_mount_label_policy, which does not exist in the Linux port.
* Illumos #3464Matthew Ahrens2013-09-041-1/+2
| | | | | | | | | | | | | | | | | 3464 zfs synctask code needs restructuring Reviewed by: Dan Kimmel <[email protected]> Reviewed by: Adam Leventhal <[email protected]> Reviewed by: George Wilson <[email protected]> Reviewed by: Christopher Siden <[email protected]> Approved by: Garrett D'Amore <[email protected]> References: https://www.illumos.org/issues/3464 illumos/illumos-gate@3b2aab18808792cbd248a12f1edf139b89833c13 Ported-by: Tim Chase <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #1495
* Constify structures containing function pointersRichard Yao2013-03-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The PaX team modified the kernel's modpost to report writeable function pointers as section mismatches because they are potential exploit targets. We could ignore the warnings, but their presence can obscure actual issues. Proper const correctness can also catch programming mistakes. Building the kernel modules against a PaX/GrSecurity patched Linux 3.4.2 kernel reports 133 section mismatches prior to this patch. This patch eliminates 130 of them. The quantity of writeable function pointers eliminated by constifying each structure is as follows: vdev_opts_t 52 zil_replay_func_t 24 zio_compress_info_t 24 zio_checksum_info_t 9 space_map_ops_t 7 arc_byteswap_func_t 5 The remaining 3 writeable function pointers cannot be addressed by this patch. 2 of them are in zpl_fs_type. The kernel's sget function requires that this be non-const. The final writeable function pointer is created by SPL_SHRINKER_DECLARE. The kernel's set_shrinker() and remove_shrinker() functions also require that this be non-const. Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #1300
* Fix 'zfs rollback' on mounted file systemsBrian Behlendorf2013-01-171-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rolling back a mounted filesystem with open file handles and cached dentries+inodes never worked properly in ZoL. The major issue was that Linux provides no easy mechanism for modules to invalidate the inode cache for a file system. Because of this it was possible that an inode from the previous filesystem would not get properly dropped from the cache during rolling back. Then a new inode with the same inode number would be create and collide with the existing cached inode. Ideally this would trigger an VERIFY() but in practice the error wasn't handled and it would just NULL reference. Luckily, this issue can be resolved by sprucing up the existing Solaris zfs_rezget() functionality for the Linux VFS. The way it works now is that when a file system is rolled back all the cached inodes will be traversed and refetched from disk. If a version of the cached inode exists on disk the in-core copy will be updated accordingly. If there is no match for that object on disk it will be unhashed from the inode cache and marked as stale. This will effectively make the inode unfindable for lookups allowing the inode number to be immediately recycled. The inode will then only be accessible from the cached dentries. Subsequent dentry lookups which reference a stale inode will result in the dentry being invalidated. Once invalidated the dentry will drop its reference on the inode allowing it to be safely pruned from the cache. Special care is taken for negative dentries since they do not reference any inode. These dentires will be invalidate based on when they were added to the dentry cache. Entries added before the last rollback will be invalidate to prevent them from masking real files in the dataset. Two nice side effects of this fix are: * Removes the dependency on spl_invalidate_inodes(), it can now be safely removed from the SPL when we choose to do so. * zfs_znode_alloc() no longer requires a dentry to be passed. This effectively reverts this portition of the code to its upstream counterpart. The dentry is not instantiated more correctly in the Linux ZPL layer. Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Ned Bass <[email protected]> Closes #795
* Directory xattr znodes hold a reference on their parentBrian Behlendorf2012-12-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unlike normal file or directory znodes, an xattr znode is guaranteed to only have a single parent. Therefore, we can take a refernce on that parent if it is provided at create time and cache it. Additionally, we take care to cache it on any subsequent zfs_zaccess() where the parent is provided as an optimization. This allows us to avoid needing to do a zfs_zget() when setting up the SELinux security xattr in the create path. This is critical because a hash lookup on the directory will deadlock since it is locked. The zpl_xattr_security_init() call has also been moved up to the zpl layer to ensure TXs to create the required xattrs are performed after the create TX. Otherwise we run the risk of deadlocking on the open create TX. Ideally the security xattr should be fully constructed before the new inode is unlocked. However, doing so would require far more extensive changes to ZFS. This change may also have the benefitial side effect of ensuring xattr directory znodes are evicted from the cache before normal file or directory znodes due to the extra reference. Signed-off-by: Brian Behlendorf <[email protected]> Closes #671
* Add .zfs control directoryBrian Behlendorf2012-03-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for the .zfs control directory. This was accomplished by leveraging as much of the existing ZFS infrastructure as posible and updating it for Linux as required. The bulk of the core functionality is now all there with the following limitations. *) The .zfs/snapshot directory automount support requires a 2.6.37 or newer kernel. The exception is RHEL6.2 which has backported the d_automount patches. *) Creating/destroying/renaming snapshots with mkdir/rmdir/mv in the .zfs/snapshot directory works as expected. However, this functionality is only available to root until zfs delegations are finished. * mkdir - create a snapshot * rmdir - destroy a snapshot * mv - rename a snapshot The following issues are known defeciences, but we expect them to be addressed by future commits. *) Add automount support for kernels older the 2.6.37. This should be possible using follow_link() which is what Linux did before. *) Accessing the .zfs/snapshot directory via NFS is not yet possible. The majority of the ground work for this is complete. However, finishing this work will require resolving some lingering integration issues with the Linux NFS kernel server. *) The .zfs/shares directory exists but no futher smb functionality has yet been implemented. Contributions-by: Rohan Puri <[email protected]> Contributiobs-by: Andrew Barnes <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #173
* Implement SA based xattrsBrian Behlendorf2011-11-281-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current ZFS implementation stores xattrs on disk using a hidden directory. In this directory a file name represents the xattr name and the file contexts are the xattr binary data. This approach is very flexible and allows for arbitrarily large xattrs. However, it also suffers from a significant performance penalty. Accessing a single xattr can requires up to three disk seeks. 1) Lookup the dnode object. 2) Lookup the dnodes's xattr directory object. 3) Lookup the xattr object in the directory. To avoid this performance penalty Linux filesystems such as ext3 and xfs try to store the xattr as part of the inode on disk. When the xattr is to large to store in the inode then a single external block is allocated for them. In practice most xattrs are small and this approach works well. The addition of System Attributes (SA) to zfs provides us a clean way to make this optimization. When the dataset property 'xattr=sa' is set then xattrs will be preferentially stored as System Attributes. This allows tiny xattrs (~100 bytes) to be stored with the dnode and up to 64k of xattrs to be stored in the spill block. If additional xattr space is required, which is unlikely under Linux, they will be stored using the traditional directory approach. This optimization results in roughly a 3x performance improvement when accessing xattrs which brings zfs roughly to parity with ext4 and xfs (see table below). When multiple xattrs are stored per-file the performance improvements are even greater because all of the xattrs stored in the spill block will be cached. However, by default SA based xattrs are disabled in the Linux port to maximize compatibility with other implementations. If you do enable SA based xattrs then they will not be visible on platforms which do not support this feature. ---------------------------------------------------------------------- Time in seconds to get/set one xattr of N bytes on 100,000 files ------+--------------------------------+------------------------------ | setxattr | getxattr bytes | ext4 xfs zfs-dir zfs-sa | ext4 xfs zfs-dir zfs-sa ------+--------------------------------+------------------------------ 1 | 2.33 31.88 21.50 4.57 | 2.35 2.64 6.29 2.43 32 | 2.79 30.68 21.98 4.60 | 2.44 2.59 6.78 2.48 256 | 3.25 31.99 21.36 5.92 | 2.32 2.71 6.22 3.14 1024 | 3.30 32.61 22.83 8.45 | 2.40 2.79 6.24 3.27 4096 | 3.57 317.46 22.52 10.73 | 2.78 28.62 6.90 3.94 16384 | n/a 2342.39 34.30 19.20 | n/a 45.44 145.90 7.55 65536 | n/a 2941.39 128.15 131.32* | n/a 141.92 256.85 262.12* Legend: * ext4 - Stock RHEL6.1 ext4 mounted with '-o user_xattr'. * xfs - Stock RHEL6.1 xfs mounted with default options. * zfs-dir - Directory based xattrs only. * zfs-sa - Prefer SAs but spill in to directories as needed, a trailing * indicates overflow in to directories occured. NOTE: Ext4 supports 4096 bytes of xattr name/value pairs per file. NOTE: XFS and ZFS have no limit on xattr name/value pairs per file. NOTE: Linux limits individual name/value pairs to 65536 bytes. NOTE: All setattr/getattr's were done after dropping the cache. NOTE: All tests were run against a single hard drive. Signed-off-by: Brian Behlendorf <[email protected]> Issue #443
* Linux compat 2.6.39: mount_nodev()Brian Behlendorf2011-07-011-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The .get_sb callback has been replaced by a .mount callback in the file_system_type structure. When using the new interface the caller must now use the mount_nodev() helper. Unfortunately, the new interface no longer passes the vfsmount down to the zfs layers. This poses a problem for the existing implementation because we currently save this pointer in the super block for latter use. It provides our only entry point in to the namespace layer for manipulating certain mount options. This needed to be done originally to allow commands like 'zfs set atime=off tank' to work properly. It also allowed me to keep more of the original Solaris code unmodified. Under Solaris there is a 1-to-1 mapping between a mount point and a file system so this is a fairly natural thing to do. However, under Linux they many be multiple entries in the namespace which reference the same filesystem. Thus keeping a back reference from the filesystem to the namespace is complicated. Rather than introduce some ugly hack to get the vfsmount and continue as before. I'm leveraging this API change to update the ZFS code to do things in a more natural way for Linux. This has the upside that is resolves the compatibility issue for the long term and fixes several other minor bugs which have been reported. This commit updates the code to remove this vfsmount back reference entirely. All modifications to filesystem mount options are now passed in to the kernel via a '-o remount'. This is the expected Linux mechanism and allows the namespace to properly handle any options which apply to it before passing them on to the file system itself. Aside from fixing the compatibility issue, removing the vfsmount has had the benefit of simplifying the code. This change which fairly involved has turned out nicely. Closes #246 Closes #217 Closes #187 Closes #248 Closes #231
* Fix evict() deadlockBrian Behlendorf2011-03-221-0/+2
| | | | | | | | | | | | | | | | | | | | | Now that KM_SLEEP is not defined as GFP_NOFS there is the possibility of synchronous reclaim deadlocks. These deadlocks never existed in the original OpenSolaris code because all memory reclaim on Solaris is done asyncronously. Linux does both synchronous (direct) and asynchronous (indirect) reclaim. This commit addresses a deadlock caused by inode eviction. A KM_SLEEP allocation may trigger direct memory reclaim and shrink the inode cache. This can occur while a mutex in the array of ZFS_OBJ_HOLD mutexes is held. Through the ->shrink_icache_memory()->evict()->zfs_inactive()-> zfs_zinactive() call path the same mutex may be reacquired resulting in a deadlock. To avoid this deadlock the process must not reacquire the mutex when it is already holding it. This is a reasonable fix for now but longer term the ZFS_OBJ_HOLD mutex locking should be reevaluated. This infrastructure already prevents us from ever using the Linux lock dependency analysis tools, and it may limit scalability.
* Register .sync_fs handlerBrian Behlendorf2011-03-151-1/+1
| | | | | | | | | Register the missing .sync_fs handler. This is a noop in most cases because the usual requirement is that sync just be initiated. As part of the DMU's normal transaction processing txgs will be frequently synced. However, when the 'wait' flag is set the requirement is that .sync_fs must not return until the data is safe on disk. With the addition of the .sync_fs handler this is now properly implemented.
* Drop HAVE_XVATTR macrosBrian Behlendorf2011-03-021-7/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When I began work on the Posix layer it immediately became clear to me that to integrate cleanly with the Linux VFS certain Solaris specific things would have to go. One of these things was to elimate as many Solaris specific types from the ZPL layer as possible. They would be replaced with their Linux equivalents. This would not only be good for performance, but for the general readability and health of the code. The Solaris and Linux VFS are different beasts and should be treated as such. Most of the code remains common for constructing transactions and such, but there are subtle and important differenced which need to be repsected. This policy went quite for for certain types such as the vnode_t, and it initially seemed to be working out well for the vattr_t. There was a relatively small amount of related xvattr_t code I was forced to comment out with HAVE_XVATTR. But it didn't look that hard to come back soon and replace it all with a native Linux type. However, after going doing this path with xvattr some distance it clear that this code was woven in the ZPL more deeply than I thought. In particular its hooks went very deep in to the ZPL replay code and replacing it would not be as easy as I originally thought. Rather than continue persuing replacing and removing this code I've taken a step back and reevaluted things. This commit reverts many of my previous commits which removed xvattr related code. It restores much of the code to its original upstream state and now relies on improved xvattr_t support in the zfs package itself. The result of this is that much of the code which I had commented out, which accidentally broke things like replay, is now back in place and working. However, there may be a small performance impact for getattr/setattr operations because they now require a translation from native Linux to Solaris types. For now that's a price I'm willing to pay. Once everything is completely functional we can revisting the issue of removing the vattr_t/xvattr_t types. Closes #111
* Add mmap(2) supportBrian Behlendorf2011-02-101-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's worth taking a moment to describe how mmap is implemented for zfs because it differs considerably from other Linux filesystems. However, this issue is handled the same way under OpenSolaris. The issue is that by design zfs bypasses the Linux page cache and leaves all caching up to the ARC. This has been shown to work well for the common read(2)/write(2) case. However, mmap(2) is problem because it relies on being tightly integrated with the page cache. To handle this we cache mmap'ed files twice, once in the ARC and a second time in the page cache. The code is careful to keep both copies synchronized. When a file with an mmap'ed region is written to using write(2) both the data in the ARC and existing pages in the page cache are updated. For a read(2) data will be read first from the page cache then the ARC if needed. Neither a write(2) or read(2) will will ever result in new pages being added to the page cache. New pages are added to the page cache only via .readpage() which is called when the vfs needs to read a page off disk to back the virtual memory region. These pages may be modified without notifying the ARC and will be written out periodically via .writepage(). This will occur due to either a sync or the usual page aging behavior. Note because a read(2) of a mmap'ed file will always check the page cache first even when the ARC is out of date correct data will still be returned. While this implementation ensures correct behavior it does have have some drawbacks. The most obvious of which is that it increases the required memory footprint when access mmap'ed files. It also adds additional complexity to the code keeping both caches synchronized. Longer term it may be possible to cleanly resolve this wart by mapping page cache pages directly on to the ARC buffers. The Linux address space operations are flexible enough to allow selection of which pages back a particular index. The trick would be working out the details of which subsystem is in charge, the ARC, the page cache, or both. It may also prove helpful to move the ARC buffers to a scatter-gather lists rather than a vmalloc'ed region. Additionally, zfs_write/read_common() were used in the readpage and writepage hooks because it was fairly easy. However, it would be better to update zfs_fillpage and zfs_putapage to be Linux friendly and use them instead.
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