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2012-08-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull second vfs pile from Al Viro: "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the deadlock reproduced by xfstests 068), symlink and hardlink restriction patches, plus assorted cleanups and fixes. Note that another fsfreeze deadlock (emergency thaw one) is *not* dealt with - the series by Fernando conflicts a lot with Jan's, breaks userland ABI (FIFREEZE semantics gets changed) and trades the deadlock for massive vfsmount leak; this is going to be handled next cycle. There probably will be another pull request, but that stuff won't be in it." Fix up trivial conflicts due to unrelated changes next to each other in drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c} * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits) delousing target_core_file a bit Documentation: Correct s_umount state for freeze_fs/unfreeze_fs fs: Remove old freezing mechanism ext2: Implement freezing btrfs: Convert to new freezing mechanism nilfs2: Convert to new freezing mechanism ntfs: Convert to new freezing mechanism fuse: Convert to new freezing mechanism gfs2: Convert to new freezing mechanism ocfs2: Convert to new freezing mechanism xfs: Convert to new freezing code ext4: Convert to new freezing mechanism fs: Protect write paths by sb_start_write - sb_end_write fs: Skip atime update on frozen filesystem fs: Add freezing handling to mnt_want_write() / mnt_drop_write() fs: Improve filesystem freezing handling switch the protection of percpu_counter list to spinlock nfsd: Push mnt_want_write() outside of i_mutex btrfs: Push mnt_want_write() outside of i_mutex fat: Push mnt_want_write() outside of i_mutex ...
2012-07-31xfs: Convert to new freezing codeJan Kara
Generic code now blocks all writers from standard write paths. So we add blocking of all writers coming from ioctl (we get a protection of ioctl against racing remount read-only as a bonus) and convert xfs_file_aio_write() to a non-racy freeze protection. We also keep freeze protection on transaction start to block internal filesystem writes such as removal of preallocated blocks. CC: Ben Myers <bpm@sgi.com> CC: Alex Elder <elder@kernel.org> CC: xfs@oss.sgi.com Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-14xfs: kill copy and paste segment checks in xfs_file_aio_readDave Chinner
The generic segment check code now returns a count of the number of bytes in the iovec, so we don't need to roll our own anymore. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-06-14xfs: make largest supported offset less shoutyDave Chinner
XFS_MAXIOFFSET() is just a simple macro that resolves to mp->m_maxioffset. It doesn't need to exist, and it just makes the code unnecessarily loud and shouty. Make it quiet and easy to read. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-06-01fs: introduce inode operation ->update_timeJosef Bacik
Btrfs has to make sure we have space to allocate new blocks in order to modify the inode, so updating time can fail. We've gotten around this by having our own file_update_time but this is kind of a pain, and Christoph has indicated he would like to make xfs do something different with atime updates. So introduce ->update_time, where we will deal with i_version an a/m/c time updates and indicate which changes need to be made. The normal version just does what it has always done, updates the time and marks the inode dirty, and then filesystems can choose to do something different. I've gone through all of the users of file_update_time and made them check for errors with the exception of the fault code since it's complicated and I wasn't quite sure what to do there, also Jan is going to be pushing the file time updates into page_mkwrite for those who have it so that should satisfy btrfs and make it not a big deal to check the file_update_time() return code in the generic fault path. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2012-05-14xfs: introduce SEEK_DATA/SEEK_HOLE supportJeff Liu
This patch adds lseek(2) SEEK_DATA/SEEK_HOLE functionality to xfs. Signed-off-by: Jie Liu <jeff.liu@oracle.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: clean up xfs_bit.h includesDave Chinner
With the removal of xfs_rw.h and other changes over time, xfs_bit.h is being included in many files that don't actually need it. Clean up the includes as necessary. Also move the only-used-once xfs_ialloc_find_free() static inline function out of a header file that is widely included to reduce the number of needless dependencies on xfs_bit.h. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: move xfsagino_t to xfs_types.hDave Chinner
Untangle the header file includes a bit by moving the definition of xfs_agino_t to xfs_types.h. This removes the dependency that xfs_ag.h has on xfs_inum.h, meaning we don't need to include xfs_inum.h everywhere we include xfs_ag.h. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: push the ilock into xfs_zero_eofChristoph Hellwig
Instead of calling xfs_zero_eof with the ilock held only take it internally for the minimall required critical section around xfs_bmapi_read. This also requires changing the calling convention for xfs_zero_last_block slightly. The actual zeroing operation is still serialized by the iolock, which must be taken exclusively over the call to xfs_zero_eof. We could in fact use a shared lock for the xfs_bmapi_read calls as long as the extent list has been read in, but given that we already hold the iolock exclusively there is little reason to micro optimize this further. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: reduce ilock hold times in xfs_file_aio_write_checksChristoph Hellwig
We do not need the ilock for generic_write_checks and the i_size_read, which are protected by i_mutex and/or iolock, so reduce the ilock critical section to just the call to xfs_zero_eof. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-03-13xfs: reimplement fdatasync supportChristoph Hellwig
Add an in-memory only flag to say we logged timestamps only, and use it to check if fdatasync can optimize away the log force. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-03-13xfs: log timestamp updatesChristoph Hellwig
Timestamps on regular files are the last metadata that XFS does not update transactionally. Now that we use the delaylog mode exclusively and made the log scode scale extremly well there is no need to bypass that code for timestamp updates. Logging all updates allows to drop a lot of code, and will allow for further performance improvements later on. Note that this patch drops optimized handling of fdatasync - it will be added back in a separate commit. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17xfs: cleanup xfs_file_aio_writeChristoph Hellwig
With all the size field updates out of the way xfs_file_aio_write can be further simplified by pushing all iolock handling into xfs_file_dio_aio_write and xfs_file_buffered_aio_write and using the generic generic_write_sync helper for synchronous writes. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17xfs: always return with the iolock held from xfs_file_aio_write_checksChristoph Hellwig
While xfs_iunlock is fine with 0 lockflags the calling conventions are much cleaner if xfs_file_aio_write_checks never returns without the iolock held. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17xfs: remove the i_new_size field in struct xfs_inodeChristoph Hellwig
Now that we use the VFS i_size field throughout XFS there is no need for the i_new_size field any more given that the VFS i_size field gets updated in ->write_end before unlocking the page, and thus is always uptodate when writeback could see a page. Removing i_new_size also has the advantage that we will never have to trim back di_size during a failed buffered write, given that it never gets updated past i_size. Note that currently the generic direct I/O code only updates i_size after calling our end_io handler, which requires a small workaround to make sure di_size actually makes it to disk. I hope to fix this properly in the generic code. A downside is that we lose the support for parallel non-overlapping O_DIRECT appending writes that recently was added. I don't think keeping the complex and fragile i_new_size infrastructure for this is a good tradeoff - if we really care about parallel appending writers we should investigate turning the iolock into a range lock, which would also allow for parallel non-overlapping buffered writers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17xfs: remove the i_size field in struct xfs_inodeChristoph Hellwig
There is no fundamental need to keep an in-memory inode size copy in the XFS inode. We already have the on-disk value in the dinode, and the separate in-memory copy that we need for regular files only in the XFS inode. Remove the xfs_inode i_size field and change the XFS_ISIZE macro to use the VFS inode i_size field for regular files. Switch code that was directly accessing the i_size field in the xfs_inode to XFS_ISIZE, or in cases where we are limited to regular files direct access of the VFS inode i_size field. This also allows dropping some fairly complicated code in the write path which dealt with keeping the xfs_inode i_size uptodate with the VFS i_size that is getting updated inside ->write_end. Note that we do not bother resetting the VFS i_size when truncating a file that gets freed to zero as there is no point in doing so because the VFS inode is no longer in use at this point. Just relax the assert in xfs_ifree to only check the on-disk size instead. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2011-12-02treewide: Fix typos in various parts of the kernel, and fix some comments.Justin P. Mattock
The below patch fixes some typos in various parts of the kernel, as well as fixes some comments. Please let me know if I missed anything, and I will try to get it changed and resent. Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-10-11xfs: optimize fsync on directoriesChristoph Hellwig
Directories are only updated transactionally, which means fsync only needs to flush the log the inode is currently dirty, but not bother with checking for dirty data, non-transactional updates, and most importanly doesn't have to flush disk caches except as part of a transaction commit. While the first two optimizations can't easily be measured, the latter actually makes a difference when doing lots of fsync that do not actually have to commit the inode, e.g. because an earlier fsync already pushed the log far enough. The new xfs_dir_fsync is identical to xfs_nfs_commit_metadata except for the prototype, but I'm not sure creating a common helper for the two is worth it given how simple the functions are. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: simplify xfs_trans_ijoin* againChristoph Hellwig
There is no reason to keep a reference to the inode even if we unlock it during transaction commit because we never drop a reference between the ijoin and commit. Also use this fact to merge xfs_trans_ijoin_ref back into xfs_trans_ijoin - the third argument decides if an unlock is needed now. I'm actually starting to wonder if allowing inodes to be unlocked at transaction commit really is worth the effort. The only real benefit is that they can be unlocked earlier when commiting a synchronous transactions, but that could be solved by doing the log force manually after the unlock, too. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: unlock the inode before log force in xfs_fsyncChristoph Hellwig
Only read the LSN we need to push to with the ilock held, and then release it before we do the log force to improve concurrency. This also removes the only direct caller of _xfs_trans_commit, thus allowing it to be merged into the plain xfs_trans_commit again. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: introduce xfs_bmapi_read()Dave Chinner
xfs_bmapi() currently handles both extent map reading and allocation. As a result, the code is littered with "if (wr)" branches to conditionally do allocation operations if required. This makes the code much harder to follow and causes significant indent issues with the code. Given that read mapping is much simpler than allocation, we can split out read mapping from xfs_bmapi() and reuse the logic that we have already factored out do do all the hard work of handling the extent map manipulations. The results in a much simpler function for the common extent read operations, and will allow the allocation code to be simplified in another commit. Once xfs_bmapi_read() is implemented, convert all the callers of xfs_bmapi() that are only reading extents to use the new function. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: avoid direct I/O write vs buffered I/O raceChristoph Hellwig
Currently a buffered reader or writer can add pages to the pagecache while we are waiting for the iolock in xfs_file_dio_aio_write. Prevent this by re-checking mapping->nrpages after we got the iolock, and if nessecary upgrade the lock to exclusive mode. To simplify this a bit only take the ilock inside of xfs_file_aio_write_checks. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: remove i_iocountChristoph Hellwig
We now have an i_dio_count filed and surrounding infrastructure to wait for direct I/O completion instead of i_icount, and we have never needed to iocount waits for buffered I/O given that we only set the page uptodate after finishing all required work. Thus remove i_iocount, and replace the actually needed waits with calls to inode_dio_wait. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: don't serialise adjacent concurrent direct IO appending writesDave Chinner
For append write workloads, extending the file requires a certain amount of exclusive locking to be done up front to ensure sanity in things like ensuring that we've zeroed any allocated regions between the old EOF and the start of the new IO. For single threads, this typically isn't a problem, and for large IOs we don't serialise enough for it to be a problem for two threads on really fast block devices. However for smaller IO and larger thread counts we have a problem. Take 4 concurrent sequential, single block sized and aligned IOs. After the first IO is submitted but before it completes, we end up with this state: IO 1 IO 2 IO 3 IO 4 +-------+-------+-------+-------+ ^ ^ | | | | | | | \- ip->i_new_size \- ip->i_size And the IO is done without exclusive locking because offset <= ip->i_size. When we submit IO 2, we see offset > ip->i_size, and grab the IO lock exclusive, because there is a chance we need to do EOF zeroing. However, there is already an IO in progress that avoids the need for IO zeroing because offset <= ip->i_new_size. hence we could avoid holding the IO lock exlcusive for this. Hence after submission of the second IO, we'd end up this state: IO 1 IO 2 IO 3 IO 4 +-------+-------+-------+-------+ ^ ^ | | | | | | | \- ip->i_new_size \- ip->i_size There is no need to grab the i_mutex of the IO lock in exclusive mode if we don't need to invalidate the page cache. Taking these locks on every direct IO effective serialises them as taking the IO lock in exclusive mode has to wait for all shared holders to drop the lock. That only happens when IO is complete, so effective it prevents dispatch of concurrent direct IO writes to the same inode. And so you can see that for the third concurrent IO, we'd avoid exclusive locking for the same reason we avoided the exclusive lock for the second IO. Fixing this is a bit more complex than that, because we need to hold a write-submission local value of ip->i_new_size to that clearing the value is only done if no other thread has updated it before our IO completes..... Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: don't serialise direct IO reads on page cache checksDave Chinner
There is no need to grab the i_mutex of the IO lock in exclusive mode if we don't need to invalidate the page cache. Taking these locks on every direct IO effective serialises them as taking the IO lock in exclusive mode has to wait for all shared holders to drop the lock. That only happens when IO is complete, so effective it prevents dispatch of concurrent direct IO reads to the same inode. Fix this by taking the IO lock shared to check the page cache state, and only then drop it and take the IO lock exclusively if there is work to be done. Hence for the normal direct IO case, no exclusive locking will occur. Signed-off-by: Dave Chinner <dchinner@redhat.com> Tested-by: Joern Engel <joern@logfs.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-08-12xfs: remove subdirectoriesChristoph Hellwig
Use the move from Linux 2.6 to Linux 3.x as an excuse to kill the annoying subdirectories in the XFS source code. Besides the large amount of file rename the only changes are to the Makefile, a few files including headers with the subdirectory prefix, and the binary sysctl compat code that includes a header under fs/xfs/ from kernel/. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>