Changes since last posting [1]: 1/ Further cleanups to dax_clear_blocks(): Dropped increments of 'addr' since we call bdev_direct_access() before the next use, and dropped the BUG_ON for sector unaligned return values from bdev_direct_access(). 2/ In [PATCH 8/8] introduce blk_dax_ctl to remove the need to have separate dax_map_atomic and __dax_map_atomic routines. Note, blk_dax_ctl is not passed through to drivers, it gets unpacked in bdev_direct_access. (Willy) 3/ New [PATCH 2/8]: Disable huge page dax mappings while we resolve various crash scenarios in this development cycle. 4/ New [PATCH 4/8]: Unmap all dax mappings at block device shutdown I have kept the reviewed-by's received to date, let me know if these incremental updates invalidate that review. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-November/002733.html --- The first 4 patches in this series I consider 4.4-rc / -stable material. The rest are for 4.5. [PATCH 4/8] needs scrutiny. It is yet another example of where DAX behavior necessarily differs from page cache behavior. I still maintain that we should not be surprising unaware applications with DAX semantics, i.e. that DAX should be per-inode opt-in, not globally enabled for all inodes at fs mount time. The largest patch in the set, [PATCH 8/8], addresses the lifetime of the 'addr' returned by bdev_direct_access. That address is only valid while the device driver is enabled. The new dax_map_atomic() / dax_unmap_atomic() pairing guarantees that 'addr' stays valid for the duration of that mapping. While dax_map_atomic() protects against 'addr' going invalid, the new calls to truncate_pagecache() via invalidate_inodes() protect against the 'pfn' returned from bdev_direct_access() going invalid. Otherwise, the storage media can be directly accessed after the driver has been disabled. --- [PATCH 1/8] ext2, ext4: warn when mounting with dax enabled [PATCH 2/8] dax: disable pmd mappings [PATCH 3/8] mm, dax: fix DAX deadlocks (COW fault) [PATCH 4/8] mm, dax: truncate dax mappings at bdev or fs shutdown [PATCH 5/8] pmem, dax: clean up clear_pmem() [PATCH 6/8] dax: increase granularity of dax_clear_blocks() operations [PATCH 7/8] dax: guarantee page aligned results from bdev_direct_access() [PATCH 8/8] dax: fix lifetime of in-kernel dax mappings with dax_map_atomic() arch/x86/include/asm/pmem.h | 7 - block/blk.h | 2 fs/Kconfig | 6 + fs/block_dev.c | 15 +-- fs/dax.c | 228 ++++++++++++++++++++++++++----------------- fs/ext2/super.c | 2 fs/ext4/super.c | 6 + fs/inode.c | 27 +++++ include/linux/blkdev.h | 19 +++- mm/memory.c | 8 +- mm/truncate.c | 13 ++ 11 files changed, 217 insertions(+), 116 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
