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2020-12-15device-dax/core: Fix memory leak when rmmod dax.koWang Hai
When I repeatedly modprobe and rmmod dax.ko, kmemleak report a memory leak as follows: unreferenced object 0xffff9a5588c05088 (size 8): comm "modprobe", pid 261, jiffies 4294693644 (age 42.063s) ... backtrace: [<00000000e007ced0>] kstrdup+0x35/0x70 [<000000002ae73897>] kstrdup_const+0x3d/0x50 [<000000002b00c9c3>] kvasprintf_const+0xbc/0xf0 [<000000008023282f>] kobject_set_name_vargs+0x3b/0xd0 [<00000000d2cbaa4e>] kobject_set_name+0x62/0x90 [<00000000202e7a22>] bus_register+0x7f/0x2b0 [<000000000b77792c>] 0xffffffffc02840f7 [<000000002d5be5ac>] 0xffffffffc02840b4 [<00000000dcafb7cd>] do_one_initcall+0x58/0x240 [<00000000049fe480>] do_init_module+0x56/0x1e2 [<0000000022671491>] load_module+0x2517/0x2840 [<000000001a2201cb>] __do_sys_finit_module+0x9c/0xe0 [<000000003eb304e7>] do_syscall_64+0x33/0x40 [<0000000051c5fd06>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 When rmmod dax is executed, dax_bus_exit() is missing. This patch can fix this bug. Fixes: 9567da0b408a ("device-dax: Introduce bus + driver model") Cc: <stable@vger.kernel.org> Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Wang Hai <wanghai38@huawei.com> Link: https://lore.kernel.org/r/20201201135929.66530-1-wanghai38@huawei.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-10-19Merge tag 'fuse-update-5.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse updates from Miklos Szeredi: - Support directly accessing host page cache from virtiofs. This can improve I/O performance for various workloads, as well as reducing the memory requirement by eliminating double caching. Thanks to Vivek Goyal for doing most of the work on this. - Allow automatic submounting inside virtiofs. This allows unique st_dev/ st_ino values to be assigned inside the guest to files residing on different filesystems on the host. Thanks to Max Reitz for the patches. - Fix an old use after free bug found by Pradeep P V K. * tag 'fuse-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (25 commits) virtiofs: calculate number of scatter-gather elements accurately fuse: connection remove fix fuse: implement crossmounts fuse: Allow fuse_fill_super_common() for submounts fuse: split fuse_mount off of fuse_conn fuse: drop fuse_conn parameter where possible fuse: store fuse_conn in fuse_req fuse: add submount support to <uapi/linux/fuse.h> fuse: fix page dereference after free virtiofs: add logic to free up a memory range virtiofs: maintain a list of busy elements virtiofs: serialize truncate/punch_hole and dax fault path virtiofs: define dax address space operations virtiofs: add DAX mmap support virtiofs: implement dax read/write operations virtiofs: introduce setupmapping/removemapping commands virtiofs: implement FUSE_INIT map_alignment field virtiofs: keep a list of free dax memory ranges virtiofs: add a mount option to enable dax virtiofs: set up virtio_fs dax_device ...
2020-09-20dax: Fix stack overflow when mounting fsdax pmem deviceAdrian Huang
When mounting fsdax pmem device, commit 6180bb446ab6 ("dax: fix detection of dax support for non-persistent memory block devices") introduces the stack overflow [1][2]. Here is the call path for mounting ext4 file system: ext4_fill_super bdev_dax_supported __bdev_dax_supported dax_supported generic_fsdax_supported __generic_fsdax_supported bdev_dax_supported The call path leads to the infinite calling loop, so we cannot call bdev_dax_supported() in __generic_fsdax_supported(). The sanity checking of the variable 'dax_dev' is moved prior to the two bdev_dax_pgoff() checks [3][4]. [1] https://lore.kernel.org/linux-nvdimm/1420999447.1004543.1600055488770.JavaMail.zimbra@redhat.com/ [2] https://lore.kernel.org/linux-nvdimm/alpine.LRH.2.02.2009141131220.30651@file01.intranet.prod.int.rdu2.redhat.com/ [3] https://lore.kernel.org/linux-nvdimm/CA+RJvhxBHriCuJhm-D8NvJRe3h2MLM+ZMFgjeJjrRPerMRLvdg@mail.gmail.com/ [4] https://lore.kernel.org/linux-nvdimm/20200903160608.GU878166@iweiny-DESK2.sc.intel.com/ Fixes: 6180bb446ab6 ("dax: fix detection of dax support for non-persistent memory block devices") Reported-by: Yi Zhang <yi.zhang@redhat.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Adrian Huang <ahuang12@lenovo.com> Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: Ritesh Harjani <riteshh@linux.ibm.com> Cc: Coly Li <colyli@suse.de> Cc: Ira Weiny <ira.weiny@intel.com> Cc: John Pittman <jpittman@redhat.com> Link: https://lore.kernel.org/r/20200917111549.6367-1-adrianhuang0701@gmail.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-09-20dm: Call proper helper to determine dax supportJan Kara
DM was calling generic_fsdax_supported() to determine whether a device referenced in the DM table supports DAX. However this is a helper for "leaf" device drivers so that they don't have to duplicate common generic checks. High level code should call dax_supported() helper which that calls into appropriate helper for the particular device. This problem manifested itself as kernel messages: dm-3: error: dax access failed (-95) when lvm2-testsuite run in cases where a DM device was stacked on top of another DM device. Fixes: 7bf7eac8d648 ("dax: Arrange for dax_supported check to span multiple devices") Cc: <stable@vger.kernel.org> Tested-by: Adrian Huang <ahuang12@lenovo.com> Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Mike Snitzer <snitzer@redhat.com> Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/r/160061715195.13131.5503173247632041975.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-09-10dax: Modify bdev_dax_pgoff() to handle NULL bdevVivek Goyal
virtiofs does not have a block device but it has dax device. Modify bdev_dax_pgoff() to be able to handle that. If there is no bdev, that means dax offset is 0. (It can't be a partition block device starting at an offset in dax device). This is little hackish. There have been discussions about getting rid of dax not supporting partitions. https://lore.kernel.org/linux-fsdevel/20200107125159.GA15745@infradead.org/ IMHO, this path can easily break exisitng users. For example ioctl(BLKPG_ADD_PARTITION) will start breaking on block devices supporting DAX. Also, I personally find it very useful to be able to partition dax devices and still be able to use DAX. Alternatively, I tried to store offset into dax device information in iomap interface, but that got NACKed. https://lore.kernel.org/linux-fsdevel/20200217133117.GB20444@infradead.org/ I can't think of a good path to solve this issue properly. So to make progress, it seems this patch is least bad option for now and I hope we can take it. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Vishal L Verma <vishal.l.verma@intel.com> Cc: "Weiny, Ira" <ira.weiny@intel.com> Cc: linux-nvdimm@lists.01.org Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-03dax: fix detection of dax support for non-persistent memory block devicesColy Li
When calling __generic_fsdax_supported(), a dax-unsupported device may not have dax_dev as NULL, e.g. the dax related code block is not enabled by Kconfig. Therefore in __generic_fsdax_supported(), to check whether a device supports DAX or not, the following order of operations should be performed: - If dax_dev pointer is NULL, it means the device driver explicitly announce it doesn't support DAX. Then it is OK to directly return false from __generic_fsdax_supported(). - If dax_dev pointer is NOT NULL, it might be because the driver doesn't support DAX and not explicitly initialize related data structure. Then bdev_dax_supported() should be called for further check. If device driver desn't explicitly set its dax_dev pointer to NULL, this is not a bug. Calling bdev_dax_supported() makes sure they can be recognized as dax-unsupported eventually. Fixes: c2affe920b0e ("dax: do not print error message for non-persistent memory block device") Cc: Jan Kara <jack@suse.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Reviewed-and-tested-by: Adrian Huang <ahuang12@lenovo.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Link: https://lore.kernel.org/r/20200903161625.19524-1-colyli@suse.de
2020-08-20dax: do not print error message for non-persistent memory block deviceAdrian Huang
Commit 231609785cbf ("dax: print error message by pr_info() in __generic_fsdax_supported()") happens to print the following error message during booting when the non-persistent memory block devices are configured by device mapper. Those error messages are caused by the variable 'dax_dev' is NULL. Users might be confused with those error messages since they do not use the persistent memory device. Moreover, users might scare about "what's wrong with my disks" because they see the 'error' and 'failed' keywords. # dmesg | grep fail sdk3: error: dax access failed (-95) sdk3: error: dax access failed (-95) sdk3: error: dax access failed (-95) sdk3: error: dax access failed (-95) sdk3: error: dax access failed (-95) sdk3: error: dax access failed (-95) sdk3: error: dax access failed (-95) sdk3: error: dax access failed (-95) sdk3: error: dax access failed (-95) sdb3: error: dax access failed (-95) sdb3: error: dax access failed (-95) sdb3: error: dax access failed (-95) sdb3: error: dax access failed (-95) sdb3: error: dax access failed (-95) sdb3: error: dax access failed (-95) sdb3: error: dax access failed (-95) sdb3: error: dax access failed (-95) sdb3: error: dax access failed (-95) # lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 1.1T 0 disk ├─sda1 8:1 0 156M 0 part ├─sda2 8:2 0 40G 0 part └─sda3 8:3 0 1.1T 0 part sdb 8:16 0 1.1T 0 disk ├─sdb1 8:17 0 600M 0 part ├─sdb2 8:18 0 1G 0 part └─sdb3 8:19 0 1.1T 0 part ├─rhel00-swap 254:3 0 4G 0 lvm ├─rhel00-home 254:4 0 1T 0 lvm └─rhel00-root 254:5 0 50G 0 lvm sdc 8:32 0 1.1T 0 disk sdd 8:48 0 1.1T 0 disk sde 8:64 0 1.1T 0 disk sdf 8:80 0 1.1T 0 disk sdg 8:96 0 1.1T 0 disk sdh 8:112 0 3.3T 0 disk ├─sdh1 8:113 0 500M 0 part /boot/efi ├─sdh2 8:114 0 40G 0 part / ├─sdh3 8:115 0 2.9T 0 part /home └─sdh4 8:116 0 314.6G 0 part [SWAP] sdi 8:128 0 1.1T 0 disk sdj 8:144 0 3.3T 0 disk ├─sdj1 8:145 0 512M 0 part └─sdj2 8:146 0 3.3T 0 part sdk 8:160 0 119.2G 0 disk ├─sdk1 8:161 0 200M 0 part ├─sdk2 8:162 0 1G 0 part └─sdk3 8:163 0 118G 0 part ├─rhel-swap 254:0 0 4G 0 lvm ├─rhel-home 254:1 0 64G 0 lvm └─rhel-root 254:2 0 50G 0 lvm sdl 8:176 0 119.2G 0 disk The call path is shown as follows: dm_table_determine_type dm_table_supports_dax device_supports_dax generic_fsdax_supported __generic_fsdax_supported With the disk configuration listing from the command 'lsblk', the member 'dev->dax_dev' of the block devices 'sdb3' and 'sdk3' (configured by device mapper) is NULL in function generic_fsdax_supported() because the member is configured in function open_table_device(). To prevent the confusing error messages in this scenario (this is normal behavior), just print those error messages by pr_debug() by checking if dax_dev is NULL and the block device does not support DAX. Link: https://lore.kernel.org/r/20200819154236.24191-1-adrianhuang0701@gmail.com Fixes: 231609785cbf ("dax: print error message by pr_info() in __generic_fsdax_supported()") Cc: Coly Li <colyli@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Acked-by: Coly Li <colyli@suse.de> Signed-off-by: Adrian Huang <ahuang12@lenovo.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2020-08-11Merge tag 'libnvdimm-for-5.9' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updayes from Vishal Verma: "You'd normally receive this pull request from Dan Williams, but he's busy watching a newborn (Congrats Dan!), so I'm watching libnvdimm this cycle. This adds a new feature in libnvdimm - 'Runtime Firmware Activation', and a few small cleanups and fixes in libnvdimm and DAX. I'd originally intended to make separate topic-based pull requests - one for libnvdimm, and one for DAX, but some of the DAX material fell out since it wasn't quite ready. Summary: - add 'Runtime Firmware Activation' support for NVDIMMs that advertise the relevant capability - misc libnvdimm and DAX cleanups" * tag 'libnvdimm-for-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: libnvdimm/security: ensure sysfs poll thread woke up and fetch updated attr libnvdimm/security: the 'security' attr never show 'overwrite' state libnvdimm/security: fix a typo ACPI: NFIT: Fix ARS zero-sized allocation dax: Fix incorrect argument passed to xas_set_err() ACPI: NFIT: Add runtime firmware activate support PM, libnvdimm: Add runtime firmware activation support libnvdimm: Convert to DEVICE_ATTR_ADMIN_RO() drivers/dax: Expand lock scope to cover the use of addresses fs/dax: Remove unused size parameter dax: print error message by pr_info() in __generic_fsdax_supported() driver-core: Introduce DEVICE_ATTR_ADMIN_{RO,RW} tools/testing/nvdimm: Emulate firmware activation commands tools/testing/nvdimm: Prepare nfit_ctl_test() for ND_CMD_CALL emulation tools/testing/nvdimm: Add command debug messages tools/testing/nvdimm: Cleanup dimm index passing ACPI: NFIT: Define runtime firmware activation commands ACPI: NFIT: Move bus_dsm_mask out of generic nvdimm_bus_descriptor libnvdimm: Validate command family indices
2020-07-28drivers/dax: Expand lock scope to cover the use of addressesIra Weiny
The addition of PKS protection to dax read lock/unlock will require that the address returned by dax_direct_access() be protected by this lock. Correct the locking by ensuring that the use of kaddr and end_kaddr are covered by the dax read lock/unlock. Link: https://lore.kernel.org/r/20200717072056.73134-12-ira.weiny@intel.com Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2020-07-28dax: print error message by pr_info() in __generic_fsdax_supported()Coly Li
In struct dax_operations, the callback routine dax_supported() returns a bool type result. For false return value, the caller has no idea whether the device does not support dax at all, or it is just some mis- configuration issue. An example is formatting an Ext4 file system on pmem device on top of a NVDIMM namespace by, # mkfs.ext4 /dev/pmem0 If the fs block size does not match kernel space memory page size (which is possible on non-x86 platform), mount this Ext4 file system will fail, # mount -o dax /dev/pmem0 /mnt mount: /mnt: wrong fs type, bad option, bad superblock on /dev/pmem0, missing codepage or helper program, or other error. And from the dmesg output there is only the following information, [ 307.853148] EXT4-fs (pmem0): DAX unsupported by block device. The above information is quite confusing. Because definitely the pmem0 device supports dax operation, and the super block is consistent as how it was created by mkfs.ext4. Indeed the failure is from __generic_fsdax_supported() by the following code piece, if (blocksize != PAGE_SIZE) { pr_debug("%s: error: unsupported blocksize for dax\n", bdevname(bdev, buf)); return false; } It is because the Ext4 block size is 4KB and kernel page size is 8KB or 16KB. It is not simple to make dax_supported() from struct dax_operations or __generic_fsdax_supported() to return exact failure type right now. So the simplest fix is to use pr_info() to print all the error messages inside __generic_fsdax_supported(). Then users may find informative clue from the kernel message at least. Message printed by pr_debug() is very easy to be ignored by users. This patch prints error message by pr_info() in __generic_fsdax_supported(), when then mount fails, following lines can be found from dmesg output, [ 2705.500885] pmem0: error: unsupported blocksize for dax [ 2705.500888] EXT4-fs (pmem0): DAX unsupported by block device. Now the users may have idea the mount failure is from pmem driver for unsupported block size. Link: https://lore.kernel.org/r/20200725162450.95999-1-colyli@suse.de Cc: Dan Williams <dan.j.williams@intel.com> Cc: Anthony Iliopoulos <ailiopoulos@suse.com> Reported-by: Michal Suchanek <msuchanek@suse.com> Suggested-by: Jan Kara <jack@suse.com> Reviewed-by: Jan Kara <jack@suse.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2020-07-01block: remove the bd_queue field from struct block_deviceChristoph Hellwig
Just use bd_disk->queue instead. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-02dax: Move mandatory ->zero_page_range() check in alloc_dax()Vivek Goyal
zero_page_range() dax operation is mandatory for dax devices. Right now that check happens in dax_zero_page_range() function. Dan thinks that's too late and its better to do the check earlier in alloc_dax(). I also modified alloc_dax() to return pointer with error code in it in case of failure. Right now it returns NULL and caller assumes failure happened due to -ENOMEM. But with this ->zero_page_range() check, I need to return -EINVAL instead. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Link: https://lore.kernel.org/r/20200401161125.GB9398@redhat.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-04-02dax, pmem: Add a dax operation zero_page_rangeVivek Goyal
Add a dax operation zero_page_range, to zero a page. This will also clear any known poison in the page being zeroed. As of now, zeroing of one page is allowed in a single call. There are no callers which are trying to zero more than a page in a single call. Once we grow the callers which zero more than a page in single call, we can add that support. Primary reason for not doing that yet is that this will add little complexity in dm implementation where a range might be spanning multiple underlying targets and one will have to split the range into multiple sub ranges and call zero_page_range() on individual targets. Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Link: https://lore.kernel.org/r/20200228163456.1587-3-vgoyal@redhat.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-01-16dax: Get rid of fs_dax_get_by_host() helperVivek Goyal
Looks like nobody is using fs_dax_get_by_host() except fs_dax_get_by_bdev() and it can easily use dax_get_by_host() instead. IIUC, fs_dax_get_by_host() was only introduced so that one could compile with CONFIG_FS_DAX=n and CONFIG_DAX=m. fs_dax_get_by_bdev() achieves the same purpose and hence it looks like fs_dax_get_by_host() is not needed anymore. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20200106181117.GA16248@redhat.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-07-19Merge branch 'work.mount0' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs mount updates from Al Viro: "The first part of mount updates. Convert filesystems to use the new mount API" * 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) mnt_init(): call shmem_init() unconditionally constify ksys_mount() string arguments don't bother with registering rootfs init_rootfs(): don't bother with init_ramfs_fs() vfs: Convert smackfs to use the new mount API vfs: Convert selinuxfs to use the new mount API vfs: Convert securityfs to use the new mount API vfs: Convert apparmorfs to use the new mount API vfs: Convert openpromfs to use the new mount API vfs: Convert xenfs to use the new mount API vfs: Convert gadgetfs to use the new mount API vfs: Convert oprofilefs to use the new mount API vfs: Convert ibmasmfs to use the new mount API vfs: Convert qib_fs/ipathfs to use the new mount API vfs: Convert efivarfs to use the new mount API vfs: Convert configfs to use the new mount API vfs: Convert binfmt_misc to use the new mount API convenience helper: get_tree_single() convenience helper get_tree_nodev() vfs: Kill sget_userns() ...
2019-07-05libnvdimm: add dax_dev sync flagPankaj Gupta
This patch adds 'DAXDEV_SYNC' flag which is set for nd_region doing synchronous flush. This later is used to disable MAP_SYNC functionality for ext4 & xfs filesystem for devices don't support synchronous flush. Signed-off-by: Pankaj Gupta <pagupta@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of version 2 of the gnu general public license as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 64 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.894819585@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-25vfs: Convert dax to use the new mount APIDavid Howells
Convert the dax filesystem to the new internal mount API as the old one will be obsoleted and removed. This allows greater flexibility in communication of mount parameters between userspace, the VFS and the filesystem. See Documentation/filesystems/mount_api.txt for more information. Signed-off-by: David Howells <dhowells@redhat.com> cc: Dan Williams <dan.j.williams@intel.com> cc: Vishal Verma <vishal.l.verma@intel.com> cc: Keith Busch <keith.busch@intel.com> cc: Dave Jiang <dave.jiang@intel.com> cc: linux-nvdimm@lists.01.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-25mount_pseudo(): drop 'name' argument, switch to d_make_root()Al Viro
Once upon a time we used to set ->d_name of e.g. pipefs root so that d_path() on pipes would work. These days it's completely pointless - dentries of pipes are not even connected to pipefs root. However, mount_pseudo() had set the root dentry name (passed as the second argument) and callers kept inventing names to pass to it. Including those that didn't *have* any non-root dentries to start with... All of that had been pointless for about 8 years now; it's time to get rid of that cargo-culting... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-21device-dax: Drop register_filesystem()Dan Williams
The device-dax fs is only there to allocate a common inode for each device-node that refers to the same device by major:minor. It is otherwise not user mountable and need not be displayed in /proc/filesystems. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-20dax: Arrange for dax_supported check to span multiple devicesDan Williams
Pankaj reports that starting with commit ad428cdb525a "dax: Check the end of the block-device capacity with dax_direct_access()" device-mapper no longer allows dax operation. This results from the stricter checks in __bdev_dax_supported() that validate that the start and end of a block-device map to the same 'pagemap' instance. Teach the dax-core and device-mapper to validate the 'pagemap' on a per-target basis. This is accomplished by refactoring the bdev_dax_supported() internals into generic_fsdax_supported() which takes a sector range to validate. Consequently generic_fsdax_supported() is suitable to be used in a device-mapper ->iterate_devices() callback. A new ->dax_supported() operation is added to allow composite devices to split and route upper-level bdev_dax_supported() requests. Fixes: ad428cdb525a ("dax: Check the end of the block-device...") Cc: <stable@vger.kernel.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Reported-by: Pankaj Gupta <pagupta@redhat.com> Reviewed-by: Pankaj Gupta <pagupta@redhat.com> Tested-by: Pankaj Gupta <pagupta@redhat.com> Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-05-01dax: make use of ->free_inode()Al Viro
we might want to drop ->destroy_inode() there - it's used only for WARN_ON() now, and AFAICS that could be moved to ->evict_inode() if we had one... Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-16Merge tag 'devdax-for-5.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull device-dax updates from Dan Williams: "New device-dax infrastructure to allow persistent memory and other "reserved" / performance differentiated memories, to be assigned to the core-mm as "System RAM". Some users want to use persistent memory as additional volatile memory. They are willing to cope with potential performance differences, for example between DRAM and 3D Xpoint, and want to use typical Linux memory management apis rather than a userspace memory allocator layered over an mmap() of a dax file. The administration model is to decide how much Persistent Memory (pmem) to use as System RAM, create a device-dax-mode namespace of that size, and then assign it to the core-mm. The rationale for device-dax is that it is a generic memory-mapping driver that can be layered over any "special purpose" memory, not just pmem. On subsequent boots udev rules can be used to restore the memory assignment. One implication of using pmem as RAM is that mlock() no longer keeps data off persistent media. For this reason it is recommended to enable NVDIMM Security (previously merged for 5.0) to encrypt pmem contents at rest. We considered making this recommendation an actively enforced requirement, but in the end decided to leave it as a distribution / administrator policy to allow for emulation and test environments that lack security capable NVDIMMs. Summary: - Replace the /sys/class/dax device model with /sys/bus/dax, and include a compat driver so distributions can opt-in to the new ABI. - Allow for an alternative driver for the device-dax address-range - Introduce the 'kmem' driver to hotplug / assign a device-dax address-range to the core-mm. - Arrange for the device-dax target-node to be onlined so that the newly added memory range can be uniquely referenced by numa apis" NOTE! I'm not entirely happy with the whole "PMEM as RAM" model because we currently have special - and very annoying rules in the kernel about accessing PMEM only with the "MC safe" accessors, because machine checks inside the regular repeat string copy functions can be fatal in some (not described) circumstances. And apparently the PMEM modules can cause that a lot more than regular RAM. The argument is that this happens because PMEM doesn't necessarily get scrubbed at boot like RAM does, but that is planned to be added for the user space tooling. Quoting Dan from another email: "The exposure can be reduced in the volatile-RAM case by scanning for and clearing errors before it is onlined as RAM. The userspace tooling for that can be in place before v5.1-final. There's also runtime notifications of errors via acpi_nfit_uc_error_notify() from background scrubbers on the DIMM devices. With that mechanism the kernel could proactively clear newly discovered poison in the volatile case, but that would be additional development more suitable for v5.2. I understand the concern, and the need to highlight this issue by tapping the brakes on feature development, but I don't see PMEM as RAM making the situation worse when the exposure is also there via DAX in the PMEM case. Volatile-RAM is arguably a safer use case since it's possible to repair pages where the persistent case needs active application coordination" * tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: device-dax: "Hotplug" persistent memory for use like normal RAM mm/resource: Let walk_system_ram_range() search child resources mm/memory-hotplug: Allow memory resources to be children mm/resource: Move HMM pr_debug() deeper into resource code mm/resource: Return real error codes from walk failures device-dax: Add a 'modalias' attribute to DAX 'bus' devices device-dax: Add a 'target_node' attribute device-dax: Auto-bind device after successful new_id acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node device-dax: Add /sys/class/dax backwards compatibility device-dax: Add support for a dax override driver device-dax: Move resource pinning+mapping into the common driver device-dax: Introduce bus + driver model device-dax: Start defining a dax bus model device-dax: Remove multi-resource infrastructure device-dax: Kill dax_region base device-dax: Kill dax_region ida
2019-02-20dax: Check the end of the block-device capacity with dax_direct_access()Dan Williams
The checks in __bdev_dax_supported() helped mitigate a potential data corruption bug in the pmem driver's handling of section alignment padding. Strengthen the checks, including checking the end of the range, to validate the dev_pagemap, Xarray entries, and sector-to-pfn translation established for pmem namespaces. Acked-by: Jan Kara <jack@suse.cz> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-01-06device-dax: Introduce bus + driver modelDan Williams
In support of multiple device-dax instances per device-dax-region and allowing the 'kmem' driver to attach to dax-instances instead of the current device-node access, convert the dax sub-system from a class to a bus. Recall that the kmem driver takes reserved / special purpose memories and assigns them to be managed by the core-mm. Aside from the fact the device-dax instances are registered and probed on a bus, two other lifetime-management changes are made: 1/ Delay attaching a cdev until driver probe time 2/ A new run_dax() helper is introduced to allow restoring dax-operation after a kill_dax() event. So, at driver ->probe() time we run_dax() and at ->remove() time we kill_dax() and invalidate all mappings. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-01-06device-dax: Start defining a dax bus modelDan Williams
Towards eliminating the dax_class, move the dax-device-attribute enabling to a new bus.c file in the core. The amount of code thrash of sub-sequent patches is reduced as no logic changes are made, just pure code movement. A temporary export of unregister_dex_dax() and dax_attribute_groups is needed to preserve compilation, but those symbols become static again in a follow-on patch. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-08-25Merge tag 'libnvdimm-for-4.19_misc' of ↵Linus Torvalds
gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dave Jiang: "Collection of misc libnvdimm patches for 4.19 submission: - Adding support to read locked nvdimm capacity. - Change test code to make DSM failure code injection an override. - Add support for calculate maximum contiguous area for namespace. - Add support for queueing a short ARS when there is on going ARS for nvdimm. - Allow NULL to be passed in to ->direct_access() for kaddr and pfn params. - Improve smart injection support for nvdimm emulation testing. - Fix test code that supports for emulating controller temperature. - Fix hang on error before devm_memremap_pages() - Fix a bug that causes user memory corruption when data returned to user for ars_status. - Maintainer updates for Ross Zwisler emails and adding Jan Kara to fsdax" * tag 'libnvdimm-for-4.19_misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm: libnvdimm: fix ars_status output length calculation device-dax: avoid hang on error before devm_memremap_pages() tools/testing/nvdimm: improve emulation of smart injection filesystem-dax: Do not request kaddr and pfn when not required md/dm-writecache: Don't request pointer dummy_addr when not required dax/super: Do not request a pointer kaddr when not required tools/testing/nvdimm: kaddr and pfn can be NULL to ->direct_access() s390, dcssblk: kaddr and pfn can be NULL to ->direct_access() libnvdimm, pmem: kaddr and pfn can be NULL to ->direct_access() acpi/nfit: queue issuing of ars when an uc error notification comes in libnvdimm: Export max available extent libnvdimm: Use max contiguous area for namespace size MAINTAINERS: Add Jan Kara for filesystem DAX MAINTAINERS: update Ross Zwisler's email address tools/testing/nvdimm: Fix support for emulating controller temperature tools/testing/nvdimm: Make DSM failure code injection an override acpi, nfit: Prefer _DSM over _LSR for namespace label reads libnvdimm: Introduce locked DIMM capacity support
2018-07-30dax/super: Do not request a pointer kaddr when not requiredHuaisheng Ye
Function __bdev_dax_supported doesn't need to get local pointer kaddr from direct_access. Using NULL instead of having to pass in a useless local pointer that caller then just throw away. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2018-06-28dax: check for QUEUE_FLAG_DAX in bdev_dax_supported()Ross Zwisler
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 <ross.zwisler@linux.intel.com> Suggested-by: Mike Snitzer <snitzer@redhat.com> Fixes: commit 545ed20e6df6 ("dm: add infrastructure for DAX support") Cc: stable@vger.kernel.org Acked-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-08Merge tag 'libnvdimm-for-4.18' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "This adds a user for the new 'bytes-remaining' updates to memcpy_mcsafe() that you already received through Ingo via the x86-dax- for-linus pull. Not included here, but still targeting this cycle, is support for handling memory media errors (poison) consumed via userspace dax mappings. Summary: - DAX broke a fundamental assumption of truncate of file mapped pages. The truncate path assumed that it is safe to disconnect a pinned page from a file and let the filesystem reclaim the physical block. With DAX the page is equivalent to the filesystem block. Introduce dax_layout_busy_page() to enable filesystems to wait for pinned DAX pages to be released. Without this wait a filesystem could allocate blocks under active device-DMA to a new file. - DAX arranges for the block layer to be bypassed and uses dax_direct_access() + copy_to_iter() to satisfy read(2) calls. However, the memcpy_mcsafe() facility is available through the pmem block driver. In order to safely handle media errors, via the DAX block-layer bypass, introduce copy_to_iter_mcsafe(). - Fix cache management policy relative to the ACPI NFIT Platform Capabilities Structure to properly elide cache flushes when they are not necessary. The table indicates whether CPU caches are power-fail protected. Clarify that a deep flush is always performed on REQ_{FUA,PREFLUSH} requests" * tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits) dax: Use dax_write_cache* helpers libnvdimm, pmem: Do not flush power-fail protected CPU caches libnvdimm, pmem: Unconditionally deep flush on *sync libnvdimm, pmem: Complete REQ_FLUSH => REQ_PREFLUSH acpi, nfit: Remove ecc_unit_size dax: dax_insert_mapping_entry always succeeds libnvdimm, e820: Register all pmem resources libnvdimm: Debug probe times linvdimm, pmem: Preserve read-only setting for pmem devices x86, nfit_test: Add unit test for memcpy_mcsafe() pmem: Switch to copy_to_iter_mcsafe() dax: Report bytes remaining in dax_iomap_actor() dax: Introduce a ->copy_to_iter dax operation uio, lib: Fix CONFIG_ARCH_HAS_UACCESS_MCSAFE compilation xfs, dax: introduce xfs_break_dax_layouts() xfs: prepare xfs_break_layouts() for another layout type xfs: prepare xfs_break_layouts() to be called with XFS_MMAPLOCK_EXCL mm, fs, dax: handle layout changes to pinned dax mappings mm: fix __gup_device_huge vs unmap mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS ...
2018-06-08Merge branch 'for-4.18/mcsafe' into libnvdimm-for-nextDan Williams
2018-06-08Merge branch 'for-4.18/dax' into libnvdimm-for-nextDan Williams
2018-06-06dax: Use dax_write_cache* helpersRoss Zwisler
Use dax_write_cache() and dax_write_cache_enabled() instead of open coding the bit operations. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-05-31dax: change bdev_dax_supported() to support boolean returnsDave Jiang
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 <dave.jiang@intel.com> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-05-31fs: allow per-device dax status checking for filesystemsDarrick J. Wong
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 <darrick.wong@oracle.com> [rez: Re-added __bdev_dax_supported() for !CONFIG_FS_DAX cases] Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2018-05-22dax: Introduce a ->copy_to_iter dax operationDan Williams
Similar to the ->copy_from_iter() operation, a platform may want to deploy an architecture or device specific routine for handling reads from a dax_device like /dev/pmemX. On x86 this routine will point to a machine check safe version of copy_to_iter(). For now, add the plumbing to device-mapper and the dax core. Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-05-22mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPSDan Williams
In preparation for fixing dax-dma-vs-unmap issues, filesystems need to be able to rely on the fact that they will get wakeups on dev_pagemap page-idle events. Introduce MEMORY_DEVICE_FS_DAX and generic_dax_page_free() as common indicator / infrastructure for dax filesytems to require. With this change there are no users of the MEMORY_DEVICE_HOST designation, so remove it. The HMM sub-system extended dev_pagemap to arrange a callback when a dev_pagemap managed page is freed. Since a dev_pagemap page is free / idle when its reference count is 1 it requires an additional branch to check the page-type at put_page() time. Given put_page() is a hot-path we do not want to incur that check if HMM is not in use, so a static branch is used to avoid that overhead when not necessary. Now, the FS_DAX implementation wants to reuse this mechanism for receiving dev_pagemap ->page_free() callbacks. Rework the HMM-specific static-key into a generic mechanism that either HMM or FS_DAX code paths can enable. For ARCH=um builds, and any other arch that lacks ZONE_DEVICE support, care must be taken to compile out the DEV_PAGEMAP_OPS infrastructure. However, we still need to support FS_DAX in the FS_DAX_LIMITED case implemented by the s390/dcssblk driver. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Reported-by: kbuild test robot <lkp@intel.com> Reported-by: Thomas Meyer <thomas@m3y3r.de> Reported-by: Dave Jiang <dave.jiang@intel.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-03-30dax: store pfns in the radixDan Williams
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 <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-02-26dax: ->direct_access does not sleep anymoreBoaz Harrosh
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 <dan.j.williams@intel.com> Signed-off-by: Boaz Harrosh <boazh@netapp.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-01-19dax: require 'struct page' by default for filesystem daxDan Williams
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 <jmoyer@redhat.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-11-14dax: fix general protection fault in dax_alloc_inodeMikulas Patocka
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: <stable@vger.kernel.org> Fixes: 7b6be8444e0f ("dax: refactor dax-fs into a generic provider...") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-11-14dax: stop requiring a live device for dax_flush()Dan Williams
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 <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-11-14dax: quiet bdev_dax_supported()Dan Williams
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 <jmoyer@redhat.com> Reviewed-by: Christ