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path: root/Documentation/filesystems/dax.txt
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2016-05-18dax: for truncate/hole-punch, do zeroing through the driver if possibleVishal Verma
In the truncate or hole-punch path in dax, we clear out sub-page ranges. If these sub-page ranges are sector aligned and sized, we can do the zeroing through the driver instead so that error-clearing is handled automatically. For sub-sector ranges, we still have to rely on clear_pmem and have the possibility of tripping over errors. Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2015-09-08dax: add huge page fault supportMatthew Wilcox
This is the support code for DAX-enabled filesystems to allow them to provide huge pages in response to faults. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-04dax: Add block size note to documentationMatthew Wilcox
For block devices which are small enough, mkfs will default to creating a filesystem with block sizes smaller than page size. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-16dax: does not work correctly with virtual aliasing cachesMatthew Wilcox
The DAX code accesses the underlying storage through the kernel's linear mapping, which may not be cache-coherent with user mappings on ARM, MIPS or SPARC. Temporarily disable the DAX code until this problem is resolved. The original XIP code also had this problem, but it was never noticed. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Andreas Dilger <andreas.dilger@intel.com> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16ext4: add DAX functionalityRoss Zwisler
This is a port of the DAX functionality found in the current version of ext2. [matthew.r.wilcox@intel.com: heavily tweaked] [akpm@linux-foundation.org: remap_pages went away] Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Andreas Dilger <andreas.dilger@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16dax: add dax_zero_page_rangeMatthew Wilcox
This new function allows us to support hole-punch for DAX files by zeroing a partial page, as opposed to the dax_truncate_page() function which can only truncate to the end of the page. Reimplement dax_truncate_page() to call dax_zero_page_range(). [ross.zwisler@linux.intel.com: ported to 3.13-rc2] [akpm@linux-foundation.org: fix typos in comments] Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Andreas Dilger <andreas.dilger@intel.com> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16dax: replace XIP documentation with DAX documentationMatthew Wilcox
Based on the original XIP documentation, this documents the current state of affairs, and includes instructions on how users can enable DAX if their devices and kernel support it. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Cc: Andreas Dilger <andreas.dilger@intel.com> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>