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* Use file_dentry and file_inode wrappersChen Haiquan2016-08-111-2/+2
| | | | | | | | | | | | Fix bugs due to kernel change in torvalds/linux@4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay"). This problem crashes system when use zfs as a layer of overlayfs. Signed-off-by: Chen Haiquan <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #4914 Closes #4935
* Linux 4.7 compat: use iterate_shared for concurrent readdirChunwei Chen2016-05-201-1/+1
| | | | | | | | | | | | | Register iterate_shared if it exists so the kernel will used shared lock and allowing concurrent readdir. Also, use shared lock when doing llseek with SEEK_DATA or SEEK_HOLE to allow concurrent seeking. Signed-off-by: Chunwei Chen <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #4664 Closes #4665
* Add temporary mount optionsBrian Behlendorf2015-09-031-5/+2
| | | | | | | | | | | | | Add the required kernel side infrastructure to parse arbitrary mount options. This enables us to support temporary mount options in largely the same way it is handled on other platforms. See the 'Temporary Mount Point Properties' section of zfs(8) for complete details. Signed-off-by: Brian Behlendorf <[email protected]> Closes #985 Closes #3351
* Restructure per-filesystem reclaimBrian Behlendorf2015-03-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Originally when the ARC prune callback was introduced the idea was to register a single callback for the ZPL. The ARC could invoke this call back if it needed the ZPL to drop dentries, inodes, or other cache objects which might be pinning buffers in the ARC. The ZPL would iterate over all ZFS super blocks and perform the reclaim. For the most part this design has worked well but due to limitations in 2.6.35 and earlier kernels there were some problems. This patch is designed to address those issues. 1) iterate_supers_type() is not provided by all kernels which makes it impossible to safely iterate over all zpl_fs_type filesystems in a single callback. The most straight forward and portable way to resolve this is to register a callback per-filesystem during mount. The arc_*_prune_callback() functions have always supported multiple callbacks so this is functionally a very small change. 2) Commit 050d22b removed the non-portable shrink_dcache_memory() and shrink_icache_memory() functions and didn't replace them with equivalent functionality. This meant that for Linux 3.1 and older kernels the ARC had no mechanism to drop dentries and inodes from the caches if needed. This patch adds that missing functionality by calling shrink_dcache_parent() to release dentries which may be pinning inodes. This will result in all unused cache entries being dropped which is a bit heavy handed but it's the only interface available for old kernels. 3) A zpl_drop_inode() callback is registered for kernels older than 2.6.35 which do not support the .evict_inode callback. This ensures that when the last reference on an inode is dropped it is immediately removed from the cache. If this isn't done than inode can end up on the global unused LRU with no mechanism available to ZFS to drop them. Since the ARC buffers are not dropped the hottest inodes can still be recreated without performing disk IO. Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Pavel Snajdr <[email protected]> Issue #3160
* Explicitly include SPL compat headersNed Bass2014-11-191-4/+5
| | | | | | | | | | | Inclusion of SPL compatibility headers was moved out of the public header sys/types.h to avoid conflicts with external packages. Include a few compatiblity headers explicitly to cope with that change. Also, sort some linux-specific inclusions alphabetically. Signed-off-by: Ned Bass <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #2898
* Implement fallocate FALLOC_FL_PUNCH_HOLETim Chase2014-09-081-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | Add support for the FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE mode of fallocate(2). Mimic the behavior of other native file systems such as ext4 in cases where the file might be extended. If the offset is beyond the end of the file, return success without changing the file. If the extent of the punched hole would extend the file, only the existing tail of the file is punched. Add the zfs_zero_partial_page() function, modeled after update_page(), to handle zeroing partial pages in a hole-punching operation. It must be used under a range lock for the requested region in order that the ARC and page cache stay in sync. Move the existing page cache truncation via truncate_setsize() into zfs_freesp() for better source structure compatibility with upstream code. Add page cache truncation to zfs_freesp() and zfs_free_range() to handle hole punching. Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Tim Chase <[email protected]> Closes #2619
* Linux AIO SupportRichard Yao2014-09-051-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nfsd uses do_readv_writev() to implement fops->read and fops->write. do_readv_writev() will attempt to read/write using fops->aio_read and fops->aio_write, but it will fallback to fops->read and fops->write when AIO is not available. However, the fallback will perform a call for each individual data page. Since our default recordsize is 128KB, sequential operations on NFS will generate 32 DMU transactions where only 1 transaction was needed. That was unnecessary overhead and we implement fops->aio_read and fops->aio_write to eliminate it. ZFS originated in OpenSolaris, where the AIO API is entirely implemented in userland's libc by intelligently mapping them to VOP_WRITE, VOP_READ and VOP_FSYNC. Linux implements AIO inside the kernel itself. Linux filesystems therefore must implement their own AIO logic and nearly all of them implement fops->aio_write synchronously. Consequently, they do not implement aio_fsync(). However, since the ZPL works by mapping Linux's VFS calls to the functions implementing Illumos' VFS operations, we instead implement AIO in the kernel by mapping the operations to the VOP_READ, VOP_WRITE and VOP_FSYNC equivalents. We therefore implement fops->aio_fsync. One might be inclined to make our fops->aio_write implementation synchronous to make software that expects this behavior safe. However, there are several reasons not to do this: 1. Other platforms do not implement aio_write() synchronously and since the majority of userland software using AIO should be cross platform, expectations of synchronous behavior should not be a problem. 2. We would hurt the performance of programs that use POSIX interfaces properly while simultaneously encouraging the creation of more non-compliant software. 3. The broader community concluded that userland software should be patched to properly use POSIX interfaces instead of implementing hacks in filesystems to cater to broken software. This concept is best described as the O_PONIES debate. 4. Making an asynchronous write synchronous is non sequitur. Any software dependent on synchronous aio_write behavior will suffer data loss on ZFSOnLinux in a kernel panic / system failure of at most zfs_txg_timeout seconds, which by default is 5 seconds. This seems like a reasonable consequence of using non-compliant software. It should be noted that this is also a problem in the kernel itself where nfsd does not pass O_SYNC on files opened with it and instead relies on a open()/write()/close() to enforce synchronous behavior when the flush is only guarenteed on last close. Exporting any filesystem that does not implement AIO via NFS risks data loss in the event of a kernel panic / system failure when something else is also accessing the file. Exporting any file system that implements AIO the way this patch does bears similar risk. However, it seems reasonable to forgo crippling our AIO implementation in favor of developing patches to fix this problem in Linux's nfsd for the reasons stated earlier. In the interim, the risk will remain. Failing to implement AIO will not change the problem that nfsd created, so there is no reason for nfsd's mistake to block our implementation of AIO. It also should be noted that `aio_cancel()` will always return `AIO_NOTCANCELED` under this implementation. It is possible to implement aio_cancel by deferring work to taskqs and use `kiocb_set_cancel_fn()` to set a callback function for cancelling work sent to taskqs, but the simpler approach is allowed by the specification: ``` Which operations are cancelable is implementation-defined. ``` http://pubs.opengroup.org/onlinepubs/009695399/functions/aio_cancel.html The only programs on my system that are capable of using `aio_cancel()` are QEMU, beecrypt and fio use it according to a recursive grep of my system's `/usr/src/debug`. That suggests that `aio_cancel()` users are rare. Implementing aio_cancel() is left to a future date when it is clear that there are consumers that benefit from its implementation to justify the work. Lastly, it is important to know that handling of the iovec updates differs between Illumos and Linux in the implementation of read/write. On Linux, it is the VFS' responsibility whle on Illumos, it is the filesystem's responsibility. We take the intermediate solution of copying the iovec so that the ZFS code can update it like on Solaris while leaving the originals alone. This imposes some overhead. We could always revisit this should profiling show that the allocations are a problem. Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #223 Closes #2373
* cstyle: Resolve C style issuesMichael Kjorling2013-12-181-11/+12
| | | | | | | | | | | | | | | | | | 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
* Add I/O Read/Write AccountingBrian Behlendorf2013-11-211-0/+1
| | | | | | | | | | | | | Because ZFS bypasses the page cache we don't inherit per-task I/O accounting for free. However, the Linux kernel does provide helper functions allow us to perform our own accounting. These are most commonly used for direct IO which also bypasses the page cache, but they can be used for the common read/write call paths as well. Signed-off-by: Pavel Snajdr <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #313 Closes #1275
* Honor CONFIG_FS_POSIX_ACL kernel optionMassimo Maggi2013-11-051-0/+14
| | | | | | | | | | | | | | | | The required Posix ACL interfaces are only available for kernels with CONFIG_FS_POSIX_ACL defined. Therefore, only enable Posix ACL support for these kernels. All major distribution kernels enable CONFIG_FS_POSIX_ACL by default. If your kernel does not support Posix ACLs the following warning will be printed at ZFS module load time. "ZFS: Posix ACLs disabled by kernel" Signed-off-by: Massimo Maggi <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #1825
* Posix ACL SupportMassimo Maggi2013-10-291-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | This change adds support for Posix ACLs by storing them as an xattr which is common practice for many Linux file systems. Since the Posix ACL is stored as an xattr it will not overwrite any existing ZFS/NFSv4 ACLs which may have been set. The Posix ACL will also be non-functional on other platforms although it may be visible as an xattr if that platform understands SA based xattrs. By default Posix ACLs are disabled but they may be enabled with the new 'aclmode=noacl|posixacl' property. Set the property to 'posixacl' to enable them. If ZFS/NFSv4 ACL support is ever added an appropriate acltype will be added. This change passes the POSIX Test Suite cleanly with the exception of xacl/00.t test 45 which is incorrect for Linux (Ext4 fails too). http://www.tuxera.com/community/posix-test-suite/ Signed-off-by: Massimo Maggi <[email protected]> Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #170
* Linux 3.11 compat: fops->iterate()Richard Yao2013-08-151-0/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit torvalds/linux@2233f31aade393641f0eaed43a71110e629bb900 replaced ->readdir() with ->iterate() in struct file_operations. All filesystems must now use the new ->iterate method. To handle this the code was reworked to use the new ->iterate interface. Care was taken to keep the majority of changes confined to the ZPL layer which is already Linux specific. However, minor changes were required to the common zfs_readdir() function. Compatibility with older kernels was accomplished by adding versions of the trivial dir_emit* helper functions. Also the various *_readdir() functions were reworked in to wrappers which create a dir_context structure to pass to the new *_iterate() functions. Unfortunately, the new dir_emit* functions prevent us from passing a private pointer to the filldir function. The xattr directory code leveraged this ability through zfs_readdir() to generate the list of xattr names. Since we can no longer use zfs_readdir() a simplified zpl_xattr_readdir() function was added to perform the same task. Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #1653 Issue #1591
* Fix 'zfs rollback' on mounted file systemsBrian Behlendorf2013-01-171-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Linux 3.3 compat, iops->create()/mkdir()/mknod()Brian Behlendorf2012-04-301-1/+1
| | | | | | | | | | The mode argument of iops->create()/mkdir()/mknod() was changed from an 'int' to a 'umode_t'. To prevent a compiler warning an autoconf check was added to detect the API change and then correctly set a zpl_umode_t typedef. There is no functional change. Signed-off-by: Brian Behlendorf <[email protected]> Closes #701
* Add .zfs control directoryBrian Behlendorf2012-03-221-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Support the fallocate() file operation.Etienne Dechamps2012-02-091-0/+3
| | | | | | | | | | | | | | Currently only the (FALLOC_FL_PUNCH_HOLE) flag combination is supported, since it's the only one that matches the behavior of zfs_space(). This makes it pretty much useless in its current form, but it's a start. To support other flag combinations we would need to modify zfs_space() to make it more flexible, or emulate the desired functionality in zpl_fallocate(). Signed-off-by: Brian Behlendorf <[email protected]> Issue #334
* Linux 3.1 compat, super_block->s_shrinkBrian Behlendorf2012-01-111-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Linux 3.1 kernel has introduced the concept of per-filesystem shrinkers which are directly assoicated with a super block. Prior to this change there was one shared global shrinker. The zfs code relied on being able to call the global shrinker when the arc_meta_limit was exceeded. This would cause the VFS to drop references on a fraction of the dentries in the dcache. The ARC could then safely reclaim the memory used by these entries and honor the arc_meta_limit. Unfortunately, when per-filesystem shrinkers were added the old interfaces were made unavailable. This change adds support to use the new per-filesystem shrinker interface so we can continue to honor the arc_meta_limit. The major benefit of the new interface is that we can now target only the zfs filesystem for dentry and inode pruning. Thus we can minimize any impact on the caching of other filesystems. In the context of making this change several other important issues related to managing the ARC were addressed, they include: * The dnlc_reduce_cache() function which was called by the ARC to drop dentries for the Posix layer was replaced with a generic zfs_prune_t callback. The ZPL layer now registers a callback to drop these dentries removing a layering violation which dates back to the Solaris code. This callback can also be used by other ARC consumers such as Lustre. arc_add_prune_callback() arc_remove_prune_callback() * The arc_reduce_dnlc_percent module option has been changed to arc_meta_prune for clarity. The dnlc functions are specific to Solaris's VFS and have already been largely eliminated already. The replacement tunable now represents the number of bytes the prune callback will request when invoked. * Less aggressively invoke the prune callback. We used to call this whenever we exceeded the arc_meta_limit however that's not strictly correct since it results in over zeleous reclaim of dentries and inodes. It is now only called once the arc_meta_limit is exceeded and every effort has been made to evict other data from the ARC cache. * More promptly manage exceeding the arc_meta_limit. When reading meta data in to the cache if a buffer was unable to be recycled notify the arc_reclaim thread to invoke the required prune. * Added arcstat_prune kstat which is incremented when the ARC is forced to request that a consumer prune its cache. Remember this will only occur when the ARC has no other choice. If it can evict buffers safely without invoking the prune callback it will. * This change is also expected to resolve the unexpect collapses of the ARC cache. This would occur because when exceeded just the arc_meta_limit reclaim presure would be excerted on the arc_c value via arc_shrink(). This effectively shrunk the entire cache when really we just needed to reclaim meta data. Signed-off-by: Brian Behlendorf <[email protected]> Closes #466 Closes #292
* Linux compat 2.6.39: mount_nodev()Brian Behlendorf2011-07-011-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Linux compat 2.6.39: security_inode_init_security()Brian Behlendorf2011-07-011-1/+2
| | | | | | | | | | | The security_inode_init_security() function now takes an additional qstr argument which must be passed in from the dentry if available. Passing a NULL is safe when no qstr is available the relevant security checks will just be skipped. Closes #246 Closes #217 Closes #187
* MMAP OptimizationPrasad Joshi2011-07-011-0/+1
| | | | | | | | | | | | | | | | | Enable zfs_getpage, zfs_fillpage, zfs_putpage, zfs_putapage functions. The functions have been modified to make them Linux friendly. ZFS uses these functions to read/write the mmapped pages. Using them from readpage/writepage results in clear code. The patch also adds readpages and writepages interface functions to read/write list of pages in one function call. The code change handles the first mmap optimization mentioned on https://github.com/behlendorf/zfs/issues/225 Signed-off-by: Prasad Joshi <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #255
* Implemented NFS export_operations.Gunnar Beutner2011-04-291-1/+2
| | | | | Implemented the required NFS operations for exporting ZFS datasets using the in-kernel NFS daemon.
* Linux 2.6.35 compat, fops->fsync()Brian Behlendorf2011-02-111-0/+1
| | | | | | | | | The fsync() callback in the file_operations structure used to take 3 arguments. The callback now only takes 2 arguments because the dentry argument was determined to be unused by all consumers. To handle this a compatibility prototype was added to ensure the right prototype is used. Our implementation never used the dentry argument either so it's just a matter of using the right prototype.
* Linux 2.6.35 compat, const struct xattr_handlerBrian Behlendorf2011-02-101-1/+2
| | | | | | | The const keyword was added to the 'struct xattr_handler' in the generic Linux super_block structure. To handle this we define an appropriate xattr_handler_t typedef which can be used. This was the preferred solution because it keeps the code clean and readable.
* Add Hooks for Linux File OperationsBrian Behlendorf2011-02-101-0/+63
The Linux specific file operations have all been located in the file zpl_file.c. These functions primarily rely on the reworked zfs_* functions to do their job. They are also responsible for converting the possible Solaris style error codes to negative Linux errors. This first zpl_* commit also includes a common zpl.h header with minimal entries to register the Linux specific hooks. In also adds all the new zpl_* file to the Makefile.in. This is not a standalone commit, you required the following zpl_* commits.