BMC/Intel-BMC/linux.git/drivers/dax/super.c, branch dev-4.17

dax: check for QUEUE_FLAG_DAX in bdev_dax_supported()

2018-07-11T14:31:33+00:00

commit 15256f6cc4b44f2e70503758150267fd2a53c0d6 upstream. Add an explicit check for QUEUE_FLAG_DAX to __bdev_dax_supported(). This is needed for DM configurations where the first element in the dm-linear or dm-stripe target supports DAX, but other elements do not. Without this check __bdev_dax_supported() will pass for such devices, letting a filesystem on that device mount with the DAX option. Signed-off-by: Ross Zwisler Suggested-by: Mike Snitzer Fixes: commit 545ed20e6df6 ("dm: add infrastructure for DAX support") Cc: stable@vger.kernel.org Acked-by: Dan Williams Reviewed-by: Toshi Kani Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dax: change bdev_dax_supported() to support boolean returns

2018-07-11T14:31:33+00:00

commit 80660f20252d6f76c9f203874ad7c7a4a8508cf8 upstream. The function return values are confusing with the way the function is named. We expect a true or false return value but it actually returns 0/-errno. This makes the code very confusing. Changing the return values to return a bool where if DAX is supported then return true and no DAX support returns false. Signed-off-by: Dave Jiang Signed-off-by: Ross Zwisler Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Greg Kroah-Hartman

fs: allow per-device dax status checking for filesystems

2018-07-11T14:31:33+00:00

commit ba23cba9b3bdc967aabdc6ff1e3e9b11ce05bb4f upstream. Change bdev_dax_supported so it takes a bdev parameter. This enables multi-device filesystems like xfs to check that a dax device can work for the particular filesystem. Once that's in place, actually fix all the parts of XFS where we need to be able to distinguish between datadev and rtdev. This patch fixes the problem where we screw up the dax support checking in xfs if the datadev and rtdev have different dax capabilities. Signed-off-by: Darrick J. Wong [rez: Re-added __bdev_dax_supported() for !CONFIG_FS_DAX cases] Signed-off-by: Ross Zwisler Reviewed-by: Eric Sandeen Signed-off-by: Greg Kroah-Hartman

dax: store pfns in the radix

2018-03-30T18:34:54+00:00

In preparation for examining the busy state of dax pages in the truncate path, switch from sectors to pfns in the radix. Cc: Jeff Moyer Cc: Christoph Hellwig Cc: Matthew Wilcox Cc: Ross Zwisler Reviewed-by: Jan Kara Signed-off-by: Dan Williams

dax: ->direct_access does not sleep anymore

2018-02-26T20:32:29+00:00

In Patch: [7a862fb] brd: remove dax support Dan Williams has removed the only might_sleep implementation of ->direct_access. So we no longer need to check for it. CC: Dan Williams Signed-off-by: Boaz Harrosh Signed-off-by: Dan Williams

dax: require 'struct page' by default for filesystem dax

2018-01-20T00:50:53+00:00

If a dax buffer from a device that does not map pages is passed to read(2) or write(2) as a target for direct-I/O it triggers SIGBUS. If gdb attempts to examine the contents of a dax buffer from a device that does not map pages it triggers SIGBUS. If fork(2) is called on a process with a dax mapping from a device that does not map pages it triggers SIGBUS. 'struct page' is required otherwise several kernel code paths break in surprising ways. Disable filesystem-dax on devices that do not map pages. In addition to needing pfn_to_page() to be valid we also require devmap pages. We need this to detect dax pages in the get_user_pages_fast() path and so that we can stop managing the VM_MIXEDMAP flag. For DAX drivers that have not supported get_user_pages() to date we allow them to opt-in to supporting DAX with the CONFIG_FS_DAX_LIMITED configuration option which requires ->direct_access() to return pfn_t_special() pfns. This leaves DAX support in brd disabled and scheduled for removal. Note that when the initial dax support was being merged a few years back there was concern that struct page was unsuitable for use with next generation persistent memory devices. The theoretical concern was that struct page access, being such a hotly used data structure in the kernel, would lead to media wear out. While that was a reasonable conservative starting position it has not held true in practice. We have long since committed to using devm_memremap_pages() to support higher order kernel functionality that needs get_user_pages() and pfn_to_page(). Cc: Jeff Moyer Cc: Ross Zwisler Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Martin Schwidefsky Cc: Heiko Carstens Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Reviewed-by: Gerald Schaefer Signed-off-by: Dan Williams

dax: fix general protection fault in dax_alloc_inode

2017-11-15T07:48:42+00:00

Don't crash in case of allocation failure in dax_alloc_inode. syzkaller hit the following crash on e4880bc5dfb1 kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access [..] RIP: 0010:dax_alloc_inode+0x3b/0x70 drivers/dax/super.c:348 Call Trace: alloc_inode+0x65/0x180 fs/inode.c:208 new_inode_pseudo+0x69/0x190 fs/inode.c:890 new_inode+0x1c/0x40 fs/inode.c:919 mount_pseudo_xattr+0x288/0x560 fs/libfs.c:261 mount_pseudo include/linux/fs.h:2137 [inline] dax_mount+0x2e/0x40 drivers/dax/super.c:388 mount_fs+0x66/0x2d0 fs/super.c:1223 Cc: Fixes: 7b6be8444e0f ("dax: refactor dax-fs into a generic provider...") Reported-by: syzbot Signed-off-by: Mikulas Patocka Signed-off-by: Dan Williams

dax: stop requiring a live device for dax_flush()

2017-11-15T00:49:15+00:00

Now that dax_flush() is no longer a driver callback (commit c3ca015fab6d "dax: remove the pmem_dax_ops->flush abstraction"), stop requiring the dax_read_lock() to be held and the device to be alive. This is in preparation for switching filesystem-dax to store pfns instead of sectors in the radix. Reviewed-by: Christoph Hellwig Signed-off-by: Dan Williams

dax: quiet bdev_dax_supported()

2017-11-15T00:48:52+00:00

Before we add another failure reason, quiet the existing log messages. Leave it to the caller to decide if bdev_dax_supported() failures are errors worth emitting to the log. Reported-by: Jeff Moyer Reviewed-by: Christoph Hellwig Signed-off-by: Dan Williams

Merge tag 'for-4.14/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2017-09-14T20:43:16+00:00

Pull device mapper updates from Mike Snitzer: - Some request-based DM core and DM multipath fixes and cleanups - Constify a few variables in DM core and DM integrity - Add bufio optimization and checksum failure accounting to DM integrity - Fix DM integrity to avoid checking integrity of failed reads - Fix DM integrity to use init_completion - A couple DM log-writes target fixes - Simplify DAX flushing by eliminating the unnecessary flush abstraction that was stood up for DM's use. * tag 'for-4.14/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dax: remove the pmem_dax_ops->flush abstraction dm integrity: use init_completion instead of COMPLETION_INITIALIZER_ONSTACK dm integrity: make blk_integrity_profile structure const dm integrity: do not check integrity for failed read operations dm log writes: fix >512b sectorsize support dm log writes: don't use all the cpu while waiting to log blocks dm ioctl: constify ioctl lookup table dm: constify argument arrays dm integrity: count and display checksum failures dm integrity: optimize writing dm-bufio buffers that are partially changed dm rq: do not update rq partially in each ending bio dm rq: make dm-sq requeuing behavior consistent with dm-mq behavior dm mpath: complain about unsupported __multipath_map_bio() return values dm mpath: avoid that building with W=1 causes gcc 7 to complain about fall-through