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2017-11-27Rename superblock flags (MS_xyz -> SB_xyz)Linus Torvalds2-28/+28
This is a pure automated search-and-replace of the internal kernel superblock flags. The s_flags are now called SB_*, with the names and the values for the moment mirroring the MS_* flags that they're equivalent to. Note how the MS_xyz flags are the ones passed to the mount system call, while the SB_xyz flags are what we then use in sb->s_flags. The script to do this was: # places to look in; re security/*: it generally should *not* be # touched (that stuff parses mount(2) arguments directly), but # there are two places where we really deal with superblock flags. FILES="drivers/mtd drivers/staging/lustre fs ipc mm \ include/linux/fs.h include/uapi/linux/bfs_fs.h \ security/apparmor/apparmorfs.c security/apparmor/include/lib.h" # the list of MS_... constants SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \ DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \ POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \ I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \ ACTIVE NOUSER" SED_PROG= for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done # we want files that contain at least one of MS_..., # with fs/namespace.c and fs/pnode.c excluded. L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c') for f in $L; do sed -i $f $SED_PROG; done Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17Merge branch 'misc.compat' of ↵Linus Torvalds1-43/+43
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull compat and uaccess updates from Al Viro: - {get,put}_compat_sigset() series - assorted compat ioctl stuff - more set_fs() elimination - a few more timespec64 conversions - several removals of pointless access_ok() in places where it was followed only by non-__ variants of primitives * 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (24 commits) coredump: call do_unlinkat directly instead of sys_unlink fs: expose do_unlinkat for built-in callers ext4: take handling of EXT4_IOC_GROUP_ADD into a helper, get rid of set_fs() ipmi: get rid of pointless access_ok() pi433: sanitize ioctl cxlflash: get rid of pointless access_ok() mtdchar: get rid of pointless access_ok() r128: switch compat ioctls to drm_ioctl_kernel() selection: get rid of field-by-field copyin VT_RESIZEX: get rid of field-by-field copyin i2c compat ioctls: move to ->compat_ioctl() sched_rr_get_interval(): move compat to native, get rid of set_fs() mips: switch to {get,put}_compat_sigset() sparc: switch to {get,put}_compat_sigset() s390: switch to {get,put}_compat_sigset() ppc: switch to {get,put}_compat_sigset() parisc: switch to {get,put}_compat_sigset() get_compat_sigset() get rid of {get,put}_compat_itimerspec() io_getevents: Use timespec64 to represent timeouts ...
2017-11-17Merge tag 'libnvdimm-for-4.15' of ↵Linus Torvalds2-6/+35
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm and dax updates from Dan Williams: "Save for a few late fixes, all of these commits have shipped in -next releases since before the merge window opened, and 0day has given a build success notification. The ext4 touches came from Jan, and the xfs touches have Darrick's reviewed-by. An xfstest for the MAP_SYNC feature has been through a few round of reviews and is on track to be merged. - Introduce MAP_SYNC and MAP_SHARED_VALIDATE, a mechanism to enable 'userspace flush' of persistent memory updates via filesystem-dax mappings. It arranges for any filesystem metadata updates that may be required to satisfy a write fault to also be flushed ("on disk") before the kernel returns to userspace from the fault handler. Effectively every write-fault that dirties metadata completes an fsync() before returning from the fault handler. The new MAP_SHARED_VALIDATE mapping type guarantees that the MAP_SYNC flag is validated as supported by the filesystem's ->mmap() file operation. - Add support for the standard ACPI 6.2 label access methods that replace the NVDIMM_FAMILY_INTEL (vendor specific) label methods. This enables interoperability with environments that only implement the standardized methods. - Add support for the ACPI 6.2 NVDIMM media error injection methods. - Add support for the NVDIMM_FAMILY_INTEL v1.6 DIMM commands for latch last shutdown status, firmware update, SMART error injection, and SMART alarm threshold control. - Cleanup physical address information disclosures to be root-only. - Fix revalidation of the DIMM "locked label area" status to support dynamic unlock of the label area. - Expand unit test infrastructure to mock the ACPI 6.2 Translate SPA (system-physical-address) command and error injection commands. Acknowledgements that came after the commits were pushed to -next: - 957ac8c421ad ("dax: fix PMD faults on zero-length files"): Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> - a39e596baa07 ("xfs: support for synchronous DAX faults") and 7b565c9f965b ("xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()") Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>" * tag 'libnvdimm-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (49 commits) acpi, nfit: add 'Enable Latch System Shutdown Status' command support dax: fix general protection fault in dax_alloc_inode dax: fix PMD faults on zero-length files dax: stop requiring a live device for dax_flush() brd: remove dax support dax: quiet bdev_dax_supported() fs, dax: unify IOMAP_F_DIRTY read vs write handling policy in the dax core tools/testing/nvdimm: unit test clear-error commands acpi, nfit: validate commands against the device type tools/testing/nvdimm: stricter bounds checking for error injection commands xfs: support for synchronous DAX faults xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault() ext4: Support for synchronous DAX faults ext4: Simplify error handling in ext4_dax_huge_fault() dax: Implement dax_finish_sync_fault() dax, iomap: Add support for synchronous faults mm: Define MAP_SYNC and VM_SYNC flags dax: Allow tuning whether dax_insert_mapping_entry() dirties entry dax: Allow dax_iomap_fault() to return pfn dax: Fix comment describing dax_iomap_fault() ...
2017-11-15mm, pagevec: remove cold parameter for pagevecsMel Gorman1-3/+3
Every pagevec_init user claims the pages being released are hot even in cases where it is unlikely the pages are hot. As no one cares about the hotness of pages being released to the allocator, just ditch the parameter. No performance impact is expected as the overhead is marginal. The parameter is removed simply because it is a bit stupid to have a useless parameter copied everywhere. Link: http://lkml.kernel.org/r/20171018075952.10627-6-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-15mm: remove nr_pages argument from pagevec_lookup_{,range}_tag()Jan Kara1-1/+1
All users of pagevec_lookup() and pagevec_lookup_range() now pass PAGEVEC_SIZE as a desired number of pages. Just drop the argument. Link: http://lkml.kernel.org/r/20171009151359.31984-15-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-15ext4: use pagevec_lookup_range_tag()Jan Kara1-12/+2
We want only pages from given range in ext4_writepages(). Use pagevec_lookup_range_tag() instead of pagevec_lookup_tag() and remove unnecessary code. Link: http://lkml.kernel.org/r/20171009151359.31984-5-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.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>
2017-11-14Merge tag 'ext4_for_linus' of ↵Linus Torvalds12-479/+245
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: - Add support for online resizing of file systems with bigalloc - Fix a two data corruption bugs involving DAX, as well as a corruption bug after a crash during a racing fallocate and delayed allocation. - Finally, a number of cleanups and optimizations. * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: improve smp scalability for inode generation ext4: add support for online resizing with bigalloc ext4: mention noload when recovering on read-only device Documentation: fix little inconsistencies ext4: convert timers to use timer_setup() jbd2: convert timers to use timer_setup() ext4: remove duplicate extended attributes defs ext4: add ext4_should_use_dax() ext4: add sanity check for encryption + DAX ext4: prevent data corruption with journaling + DAX ext4: prevent data corruption with inline data + DAX ext4: fix interaction between i_size, fallocate, and delalloc after a crash ext4: retry allocations conservatively ext4: Switch to iomap for SEEK_HOLE / SEEK_DATA ext4: Add iomap support for inline data iomap: Add IOMAP_F_DATA_INLINE flag iomap: Switch from blkno to disk offset
2017-11-14Merge tag 'fscrypt-for-linus' of ↵Linus Torvalds5-86/+41
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt Pull fscrypt updates from Ted Ts'o: "Lots of cleanups, mostly courtesy by Eric Biggers" * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt: fscrypt: lock mutex before checking for bounce page pool fscrypt: add a documentation file for filesystem-level encryption ext4: switch to fscrypt_prepare_setattr() ext4: switch to fscrypt_prepare_lookup() ext4: switch to fscrypt_prepare_rename() ext4: switch to fscrypt_prepare_link() ext4: switch to fscrypt_file_open() fscrypt: new helper function - fscrypt_prepare_setattr() fscrypt: new helper function - fscrypt_prepare_lookup() fscrypt: new helper function - fscrypt_prepare_rename() fscrypt: new helper function - fscrypt_prepare_link() fscrypt: new helper function - fscrypt_file_open() fscrypt: new helper function - fscrypt_require_key() fscrypt: remove unneeded empty fscrypt_operations structs fscrypt: remove ->is_encrypted() fscrypt: switch from ->is_encrypted() to IS_ENCRYPTED() fs, fscrypt: add an S_ENCRYPTED inode flag fscrypt: clean up include file mess
2017-11-13fs, dax: unify IOMAP_F_DIRTY read vs write handling policy in the dax coreDan Williams1-1/+1
While reviewing whether MAP_SYNC should strengthen its current guarantee of syncing writes from the initiating process to also include third-party readers observing dirty metadata, Dave pointed out that the check of IOMAP_WRITE is misplaced. The policy of what to with IOMAP_F_DIRTY should be separated from the generic filesystem mechanism of reporting dirty metadata. Move this policy to the fs-dax core to simplify the per-filesystem iomap handlers, and further centralize code that implements the MAP_SYNC policy. This otherwise should not change behavior, it just makes it easier to change behavior in the future. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reported-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-11-10ext4: take handling of EXT4_IOC_GROUP_ADD into a helper, get rid of set_fs()Al Viro1-43/+43
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-08ext4: improve smp scalability for inode generationTheodore Ts'o4-12/+4
->s_next_generation is protected by s_next_gen_lock but its usage pattern is very primitive. We don't actually need sequentially increasing new generation numbers, so let's use prandom_u32() instead. Reported-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-11-03ext4: Support for synchronous DAX faultsJan Kara2-1/+29
We return IOMAP_F_DIRTY flag from ext4_iomap_begin() when asked to prepare blocks for writing and the inode has some uncommitted metadata changes. In the fault handler ext4_dax_fault() we then detect this case (through VM_FAULT_NEEDDSYNC return value) and call helper dax_finish_sync_fault() to flush metadata changes and insert page table entry. Note that this will also dirty corresponding radix tree entry which is what we want - fsync(2) will still provide data integrity guarantees for applications not using userspace flushing. And applications using userspace flushing can avoid calling fsync(2) and thus avoid the performance overhead. Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-11-03ext4: Simplify error handling in ext4_dax_huge_fault()Jan Kara1-6/+7
If transaction starting fails, just bail out of the function immediately instead of checking for that condition throughout the function. Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-11-03dax: Allow dax_iomap_fault() to return pfnJan Kara1-1/+1
For synchronous page fault dax_iomap_fault() will need to return PFN which will then need to be inserted into page tables after fsync() completes. Add necessary parameter to dax_iomap_fault(). Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman31-0/+31
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-29ext4: add support for online resizing with bigallocharshads4-58/+84
This patch adds support for online resizing on bigalloc file system by implementing EXT4_IOC_RESIZE_FS ioctl. Old resize interfaces (add block groups and extend last block group) are left untouched. Tests performed with cluster sizes of 1, 2, 4 and 8 blocks (of size 4k) per cluster. I will add these tests to xfstests. Signed-off-by: Harshad Shirwadkar <harshads@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-18ext4: switch to fscrypt_prepare_setattr()Eric Biggers1-8/+4
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-18ext4: switch to fscrypt_prepare_lookup()Eric Biggers1-16/+6
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-18ext4: switch to fscrypt_prepare_rename()Eric Biggers1-26/+7
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-18ext4: switch to fscrypt_prepare_link()Eric Biggers1-3/+4
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-18ext4: switch to fscrypt_file_open()Eric Biggers1-19/+4
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-18fscrypt: remove unneeded empty fscrypt_operations structsEric Biggers1-3/+2
In the case where a filesystem has been configured without encryption support, there is no longer any need to initialize ->s_cop at all, since none of the methods are ever called. Reviewed-by: Chao Yu <yuchao0@huawei.com> Acked-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-18fscrypt: remove ->is_encrypted()Eric Biggers1-2/+0
Now that all callers of fscrypt_operations.is_encrypted() have been switched to IS_ENCRYPTED(), remove ->is_encrypted(). Reviewed-by: Chao Yu <yuchao0@huawei.com> Acked-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-18fs, fscrypt: add an S_ENCRYPTED inode flagEric Biggers2-4/+11
Introduce a flag S_ENCRYPTED which can be set in ->i_flags to indicate that the inode is encrypted using the fscrypt (fs/crypto/) mechanism. Checking this flag will give the same information that inode->i_sb->s_cop->is_encrypted(inode) currently does, but will be more efficient. This will be useful for adding higher-level helper functions for filesystems to use. For example we'll be able to replace this: if (ext4_encrypted_inode(inode)) { ret = fscrypt_get_encryption_info(inode); if (ret) return ret; if (!fscrypt_has_encryption_key(inode)) return -ENOKEY; } with this: ret = fscrypt_require_key(inode); if (ret) return ret; ... since we'll be able to retain the fast path for unencrypted files as a single flag check, using an inline function. This wasn't possible before because we'd have had to frequently call through the ->i_sb->s_cop->is_encrypted function pointer, even when the encryption support was disabled or not being used. Note: we don't define S_ENCRYPTED to 0 if CONFIG_FS_ENCRYPTION is disabled because we want to continue to return an error if an encrypted file is accessed without encryption support, rather than pretending that it is unencrypted. Reviewed-by: Chao Yu <yuchao0@huawei.com> Acked-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-18fscrypt: clean up include file messDave Chinner1-5/+3
Filesystems have to include different header files based on whether they are compiled with encryption support or not. That's nasty and messy. Instead, rationalise the headers so we have a single include fscrypt.h and let it decide what internal implementation to include based on the __FS_HAS_ENCRYPTION define. Filesystems set __FS_HAS_ENCRYPTION to 1 before including linux/fscrypt.h if they are built with encryption support. Otherwise, they must set __FS_HAS_ENCRYPTION to 0. Add guards to prevent fscrypt_supp.h and fscrypt_notsupp.h from being directly included by filesystems. Signed-off-by: Dave Chinner <dchinner@redhat.com> [EB: use 1 and 0 rather than defined/undefined] Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-18Convert fs/*/* to SB_I_VERSIONMatthew Garrett1-2/+2
[AV: in addition to the fix in previous commit] Signed-off-by: Matthew Garrett <mjg59@google.com> Cc: David Howells <dhowells@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-10-18ext4: mention noload when recovering on read-only deviceSimon Ruderich1-1/+2
Help the user to find the appropriate mount option to continue mounting the file system on a read-only device if the journal requires recovery. Signed-off-by: Simon Ruderich <simon@ruderich.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-18ext4: convert timers to use timer_setup()Kees Cook1-9/+5
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Reviewed-by: Jan Kara <jack@suse.cz> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: linux-ext4@vger.kernel.org
2017-10-12ext4: remove duplicate extended attributes defsRoss Zwisler1-37/+0
The following commit: commit 9b7365fc1c82 ("ext4: add FS_IOC_FSSETXATTR/FS_IOC_FSGETXATTR interface support") added several defines related to extended attributes to ext4.h. They were added within an #ifndef FS_IOC_FSGETXATTR block with the comment: /* Until the uapi changes get merged for project quota... */ Those uapi changes were merged by this commit: commit 334e580a6f97 ("fs: XFS_IOC_FS[SG]SETXATTR to FS_IOC_FS[SG]ETXATTR promotion") so all the definitions needed by ext4 are available in include/uapi/linux/fs.h. Remove the duplicates from ext4.h. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-10-12ext4: add ext4_should_use_dax()Ross Zwisler1-3/+16
This helper, in the spirit of ext4_should_dioread_nolock() et al., replaces the complex conditional in ext4_set_inode_flags(). Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-10-12ext4: add sanity check for encryption + DAXRoss Zwisler1-0/+3
We prevent DAX from being used on inodes which are using ext4's built in encryption via a check in ext4_set_inode_flags(). We do have what appears to be an unsafe transition of S_DAX in ext4_set_context(), though, where S_DAX can get disabled without us doing a proper writeback + invalidate. There are also issues with mm-level races when changing the value of S_DAX, as well as issues with the VM_MIXEDMAP flag: https://www.spinics.net/lists/linux-xfs/msg09859.html I actually think we are safe in this case because of the following: 1) You can't encrypt an existing file. Encryption can only be set on an empty directory, with new inodes in that directory being created with encryption turned on, so I don't think it's possible to turn encryption on for a file that has open DAX mmaps or outstanding I/Os. 2) There is no way to turn encryption off on a given file. Once an inode is encrypted, it stays encrypted for the life of that inode, so we don't have to worry about the case where we turn encryption off and S_DAX suddenly turns on. 3) The only way we end up in ext4_set_context() to turn on encryption is when we are creating a new file in the encrypted directory. This happens as part of ext4_create() before the inode has been allowed to do any I/O. Here's the call tree: ext4_create() __ext4_new_inode() ext4_set_inode_flags() // sets S_DAX fscrypt_inherit_context() fscrypt_get_encryption_info(); ext4_set_context() // sets EXT4_INODE_ENCRYPT, clears S_DAX So, I actually think it's safe to transition S_DAX in ext4_set_context() without any locking, writebacks or invalidations. I've added a WARN_ON_ONCE() sanity check to make sure that we are notified if we ever encounter a case where we are encrypting an inode that already has data, in which case we need to add code to safely transition S_DAX. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-10-12ext4: prevent data corruption with journaling + DAXRoss Zwisler2-8/+13
The current code has the potential for data corruption when changing an inode's journaling mode, as that can result in a subsequent unsafe change in S_DAX. I've captured an instance of this data corruption in the following fstest: https://patchwork.kernel.org/patch/9948377/ Prevent this data corruption from happening by disallowing changes to the journaling mode if the '-o dax' mount option was used. This means that for a given filesystem we could have a mix of inodes using either DAX or data journaling, but whatever state the inodes are in will be held for the duration of the mount. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@vger.kernel.org
2017-10-12ext4: prevent data corruption with inline data + DAXRoss Zwisler2-10/+5
If an inode has inline data it is currently prevented from using DAX by a check in ext4_set_inode_flags(). When the inode grows inline data via ext4_create_inline_data() or removes its inline data via ext4_destroy_inline_data_nolock(), the value of S_DAX can change. Currently these changes are unsafe because we don't hold off page faults and I/O, write back dirty radix tree entries and invalidate all mappings. There are also issues with mm-level races when changing the value of S_DAX, as well as issues with the VM_MIXEDMAP flag: https://www.spinics.net/lists/linux-xfs/msg09859.html The unsafe transition of S_DAX can reliably cause data corruption, as shown by the following fstest: https://patchwork.kernel.org/patch/9948381/ Fix this issue by preventing the DAX mount option from being used on filesystems that were created to support inline data. Inline data is an option given to mkfs.ext4. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> CC: stable@vger.kernel.org
2017-10-06ext4: fix interaction between i_size, fallocate, and delalloc after a crashTheodore Ts'o1-2/+4
If there are pending writes subject to delayed allocation, then i_size will show size after the writes have completed, while i_disksize contains the value of i_size on the disk (since the writes have not been persisted to disk). If fallocate(2) is called with the FALLOC_FL_KEEP_SIZE flag, either with or without the FALLOC_FL_ZERO_RANGE flag set, and the new size after the fallocate(2) is between i_size and i_disksize, then after a crash, if a journal commit has resulted in the changes made by the fallocate() call to be persisted after a crash, but the delayed allocation write has not resolved itself, i_size would not be updated, and this would cause the following e2fsck complaint: Inode 12, end of extent exceeds allowed value (logical block 33, physical block 33441, len 7) This can only take place on a sparse file, where the fallocate(2) call is allocating blocks in a range which is before a pending delayed allocation write which is extending i_size. Since this situation is quite rare, and the window in which the crash must take place is typically < 30 seconds, in practice this condition will rarely happen. Nevertheless, it can be triggered in testing, and in particular by xfstests generic/456. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reported-by: Amir Goldstein <amir73il@gmail.com> Cc: stable@vger.kernel.org
2017-10-01ext4: retry allocations conservativelyTheodore Ts'o1-8/+7
Now that we no longer try to reserve metadata blocks for delayed allocations (which tended to overestimate the required number of blocks significantly), we really don't need retry allocations when the disk is very full as aggressively any more. The only time when it makes sense to retry an allocation is if we have freshly deleted blocks that will only become available after a transaction commit. And if we lose that race, it's not worth it to try more than once. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-01ext4: Switch to iomap for SEEK_HOLE / SEEK_DATAChristoph Hellwig4-327/+49
Switch to the iomap_seek_hole and iomap_seek_data helpers for implementing lseek SEEK_HOLE / SEEK_DATA, and remove all the code that isn't needed any more. Note that with this patch ext4 will now always depend on the iomap code instead of only when CONFIG_DAX is enabled, and it requires adding a call into the extent status tree for iomap_begin as well to properly deal with delalloc extents. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> [More fixes and cleanups by Andreas]
2017-10-01ext4: Add iomap support for inline dataAndreas Gruenbacher3-2/+51
Report inline data as a IOMAP_F_DATA_INLINE mapping. This allows to use iomap_seek_hole and iomap_seek_data in ext4_llseek and makes switching to iomap_fiemap in ext4_fiemap easier. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-10-01iomap: Switch from blkno to disk offsetAndreas Gruenbacher1-2/+2
Replace iomap->blkno, the sector number, with iomap->addr, the disk offset in bytes. For invalid disk offsets, use the special value IOMAP_NULL_ADDR instead of IOMAP_NULL_BLOCK. This allows to use iomap for mappings which are not block aligned, such as inline data on ext4. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> # iomap, xfs Reviewed-by: Jan Kara <jack@suse.cz>
2017-09-14Merge branch 'work.read_write' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull nowait read support from Al Viro: "Support IOCB_NOWAIT for buffered reads and block devices" * 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: block_dev: support RFW_NOWAIT on block device nodes fs: support RWF_NOWAIT for buffered reads fs: support IOCB_NOWAIT in generic_file_buffered_read fs: pass iocb to do_generic_file_read
2017-09-14Merge branch 'work.mount' of ↵Linus Torvalds6-33/+30
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull mount flag updates from Al Viro: "Another chunk of fmount preparations from dhowells; only trivial conflicts for that part. It separates MS_... bits (very grotty mount(2) ABI) from the struct super_block ->s_flags (kernel-internal, only a small subset of MS_... stuff). This does *not* convert the filesystems to new constants; only the infrastructure is done here. The next step in that series is where the conflicts would be; that's the conversion of filesystems. It's purely mechanical and it's better done after the merge, so if you could run something like list=$(for i in MS_RDONLY MS_NOSUID MS_NODEV MS_NOEXEC MS_SYNCHRONOUS MS_MANDLOCK MS_DIRSYNC MS_NOATIME MS_NODIRATIME MS_SILENT MS_POSIXACL MS_KERNMOUNT MS_I_VERSION MS_LAZYTIME; do git grep -l $i fs drivers/staging/lustre drivers/mtd ipc mm include/linux; done|sort|uniq|grep -v '^fs/namespace.c$') sed -i -e 's/\<MS_RDONLY\>/SB_RDONLY/g' \ -e 's/\<MS_NOSUID\>/SB_NOSUID/g' \ -e 's/\<MS_NODEV\>/SB_NODEV/g' \ -e 's/\<MS_NOEXEC\>/SB_NOEXEC/g' \ -e 's/\<MS_SYNCHRONOUS\>/SB_SYNCHRONOUS/g' \ -e 's/\<MS_MANDLOCK\>/SB_MANDLOCK/g' \ -e 's/\<MS_DIRSYNC\>/SB_DIRSYNC/g' \ -e 's/\<MS_NOATIME\>/SB_NOATIME/g' \ -e 's/\<MS_NODIRATIME\>/SB_NODIRATIME/g' \ -e 's/\<MS_SILENT\>/SB_SILENT/g' \ -e 's/\<MS_POSIXACL\>/SB_POSIXACL/g' \ -e 's/\<MS_KERNMOUNT\>/SB_KERNMOUNT/g' \ -e 's/\<MS_I_VERSION\>/SB_I_VERSION/g' \ -e 's/\<MS_LAZYTIME\>/SB_LAZYTIME/g' \ $list and commit it with something along the lines of 'convert filesystems away from use of MS_... constants' as commit message, it would save a quite a bit of headache next cycle" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: VFS: Differentiate mount flags (MS_*) from internal superblock flags VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb) vfs: Add sb_rdonly(sb) to query the MS_RDONLY flag on s_flags
2017-09-11Merge tag 'libnvdimm-for-4.14' of ↵Linus Torvalds3-8/+8
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm from Dan Williams: "A rework of media error handling in the BTT driver and other updates. It has appeared in a few -next releases and collected some late- breaking build-error and warning fixups as a result. Summary: - Media error handling support in the Block Translation Table (BTT) driver is reworked to address sleeping-while-atomic locking and memory-allocation-context conflicts. - The dax_device lookup overhead for xfs and ext4 is moved out of the iomap hot-path to a mount-time lookup. - A new 'ecc_unit_size' sysfs attribute is added to advertise the read-modify-write boundary property of a persistent memory range. - Preparatory fix-ups for arm and powerpc pmem support are included along with other miscellaneous fixes" * tag 'libnvdimm-for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (26 commits) libnvdimm, btt: fix format string warnings libnvdimm, btt: clean up warning and error messages ext4: fix null pointer dereference on sbi libnvdimm, nfit: move the check on nd_reserved2 to the endpoint dax: fix FS_DAX=n BLOCK=y compilation libnvdimm: fix integer overflow static analysis warning libnvdimm, nd_blk: remove mmio_flush_range() libnvdimm, btt: rework error clearing libnvdimm: fix potential deadlock while clearing errors libnvdimm, btt: cache sector_size in arena_info libnvdimm, btt: ensure that flags were also unchanged during a map_read libnvdimm, btt: refactor map entry operations with macros libnvdimm, btt: fix a missed NVDIMM_IO_ATOMIC case in the write path libnvdimm, nfit: export an 'ecc_unit_size' sysfs attribute ext4: perform dax_device lookup at mount ext2: perform dax_device lookup at mount xfs: perform dax_device lookup at mount dax: introduce a fs_dax_get_by_bdev() helper libnvdimm, btt: check memory allocation failure libnvdimm, label: fix index block size calculation ...
2017-09-07Merge branch 'quota_scaling' of ↵Linus Torvalds1-12/+14
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull quota scaling updates from Jan Kara: "This contains changes to make the quota subsystem more scalable. Reportedly it improves number of files created per second on ext4 filesystem on fast storage by about a factor of 2x" * 'quota_scaling' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (28 commits) quota: Add lock annotations to struct members quota: Reduce contention on dq_data_lock fs: Provide __inode_get_bytes() quota: Inline dquot_[re]claim_reserved_space() into callsite quota: Inline inode_{incr,decr}_space() into callsites quota: Inline functions into their callsites ext4: Disable dirty list tracking of dquots when journalling quotas quota: Allow disabling tracking of dirty dquots in a list quota: Remove dq_wait_unused from dquot quota: Move locking into clear_dquot_dirty() quota: Do not dirty bad dquots quota: Fix possible corruption of dqi_flags quota: Propagate ->quota_read errors from v2_read_file_info() quota: Fix error codes in v2_read_file_info() quota: Push dqio_sem down to ->read_file_info() quota: Push dqio_sem down to ->write_file_info() quota: Push dqio_sem down to ->get_next_id() quota: Push dqio_sem down to ->release_dqblk() quota: Remove locking for writing to the old quota format quota: Do not acquire dqio_sem for dquot overwrites in v2 format ...
2017-09-07Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-blockLinus Torvalds2-3/+3
Pull block layer updates from Jens Axboe: "This is the first pull request for 4.14, containing most of the code changes. It's a quiet series this round, which I think we needed after the churn of the last few series. This contains: - Fix for a registration race in loop, from Anton Volkov. - Overflow complaint fix from Arnd for DAC960. - Series of drbd changes from the usual suspects. - Conversion of the stec/skd driver to blk-mq. From Bart. - A few BFQ improvements/fixes from Paolo. - CFQ improvement from Ritesh, allowing idling for group idle. - A few fixes found by Dan's smatch, courtesy of Dan. - A warning fixup for a race between changing the IO scheduler and device remova. From David Jeffery. - A few nbd fixes from Josef. - Support for cgroup info in blktrace, from Shaohua. - Also from Shaohua, new features in the null_blk driver to allow it to actually hold data, among other things. - Various corner cases and error handling fixes from Weiping Zhang. - Improvements to the IO stats tracking for blk-mq from me. Can drastically improve performance for fast devices and/or big machines. - Series from Christoph removing bi_bdev as being needed for IO submission, in preparation for nvme multipathing code. - Series from Bart, including various cleanups and fixes for switch fall through case complaints" * 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits) kernfs: checking for IS_ERR() instead of NULL drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set drbd: Fix allyesconfig build, fix recent commit drbd: switch from kmalloc() to kmalloc_array() drbd: abort drbd_start_resync if there is no connection drbd: move global variables to drbd namespace and make some static drbd: rename "usermode_helper" to "drbd_usermode_helper" drbd: fix race between handshake and admin disconnect/down drbd: fix potential deadlock when trying to detach during handshake drbd: A single dot should be put into a sequence. drbd: fix rmmod cleanup, remove _all_ debugfs entries drbd: Use setup_timer() instead of init_timer() to simplify the code. drbd: fix potential get_ldev/put_ldev refcount imbalance during attach drbd: new disk-option disable-write-same drbd: Fix resource role for newly created resources in events2 drbd: mark symbols static where possible drbd: Send P_NEG_ACK upon write error in protocol != C drbd: add explicit plugging when submitting batches drbd: change list_for_each_safe to while(list_first_entry_or_null) drbd: introduce drbd_recv_header_maybe_unplug ...
2017-09-06Merge branch 'akpm' (patches from Andrew)Linus Torvalds2-54/+9
Merge updates from Andrew Morton: - various misc bits - DAX updates - OCFS2 - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (119 commits) mm,fork: introduce MADV_WIPEONFORK x86,mpx: make mpx depend on x86-64 to free up VMA flag mm: add /proc/pid/smaps_rollup mm: hugetlb: clear target sub-page last when clearing huge page mm: oom: let oom_reap_task and exit_mmap run concurrently swap: choose swap device according to numa node mm: replace TIF_MEMDIE checks by tsk_is_oom_victim mm, oom: do not rely on TIF_MEMDIE for memory reserves access z3fold: use per-cpu unbuddied lists mm, swap: don't use VMA based swap readahead if HDD is used as swap mm, swap: add sysfs interface for VMA based swap readahead mm, swap: VMA based swap readahead mm, swap: fix swap readahead marking mm, swap: add swap readahead hit statistics mm/vmalloc.c: don't reinvent the wheel but use existing llist API mm/vmstat.c: fix wrong comment selftests/memfd: add memfd_create hugetlbfs selftest mm/shmem: add hugetlbfs support to memfd_create() mm, devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups mm/vmalloc.c: halve the number of comparisons performed in pcpu_get_vm_areas() ...
2017-09-06mm: remove nr_pages argument from pagevec_lookup{,_range}()Jan Kara2-4/+3
All users of pagevec_lookup() and pagevec_lookup_range() now pass PAGEVEC_SIZE as a desired number of pages. Just drop the argument. Link: http://lkml.kernel.org/r/20170726114704.7626-11-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06ext4: use pagevec_lookup_range() in writeback codeJan Kara1-7/+5
Both occurences of pagevec_lookup() actually want only pages from a given range. Use pagevec_lookup_range() for the lookup. Link: http://lkml.kernel.org/r/20170726114704.7626-7-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> 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>
2017-09-06ext4: use pagevec_lookup_range() in ext4_find_unwritten_pgoff()Jan Kara1-10/+4
Use pagevec_lookup_range() in ext4_find_unwritten_pgoff() since we are interested only in pages in the given range. Simplify the logic as a result of not getting pages out of range and index getting automatically advanced. Link: http://lkml.kernel.org/r/20170726114704.7626-6-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> 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>
2017-09-06mm: make pagevec_lookup() update indexJan Kara2-9/+3
Make pagevec_lookup() (and underlying find_get_pages()) update index to the next page where iteration should continue. Most callers want this and also pagevec_lookup_tag() already does this. Link: http://lkml.kernel.org/r/20170726114704.7626-3-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06dax: use common 4k zero page for dax mmap readsRoss Zwisler1-31/+1
When servicing mmap() reads from file holes the current DAX code allocates a page cache page of all zeroes and places the struct page pointer in the mapping->page_tree radix tree. This has three major drawbacks: 1) It consumes memory unnecessarily. For every 4k page that is read via a DAX mmap() over a hole, we allocate a new page cache page. This means that if you read 1GiB worth of pages, you end up using 1GiB of zeroed memory. This is easily visible by looking at the overall memory consumption of the system or by looking at /proc/[pid]/smaps: 7f62e72b3000-7f63272b3000 rw-s 00000000 103:00 12 /root/dax/data Size: 1048576 kB Rss: 1048576 kB Pss: 1048576 kB Shared_Clean: 0 kB Shared_Dirty: 0 kB Private_Clean: 1048576 kB Private_Dirty: 0 kB Referenced: 1048576 kB Anonymous: 0 kB LazyFree: 0 kB AnonHugePages: 0 kB ShmemPmdMapped: 0 kB Shared_Hugetlb: 0 kB Private_Hugetlb: 0 kB Swap: 0 kB SwapPss: 0 kB KernelPageSize: 4 kB MMUPageSize: 4 kB Locked: 0 kB 2) It is slower than using a common zero page because each page fault has more work to do. Instead of just inserting a common zero page we have to allocate a page cache page, zero it, and then insert it. Here are the average latencies of dax_load_hole() as measured by ftrace on a random test box: Old method, using zeroed page cache pages: 3.4 us New method, using the common 4k zero page: 0.8 us This was the average latency over 1 GiB of sequential reads done by this simple fio script: [global] size=1G filename=/root/dax/data fallocate=none [io] rw=read ioengine=mmap 3) The fact that we had to check for both DAX exceptional entries and for page cache pages in the radix tree made the DAX code more complex. Solve these issues by following the lead of the DAX PMD code and using a common 4k zero page instead. As with the PMD code we will now insert a DAX exceptional entry into the radix tree instead of a struct page pointer which allows us to remove all the special casing in the DAX code. Note that we do still pretty aggressively check for regular pages in the DAX radix tree, especially where we take action based on the bits set in the page. If we ever find a regular page in our radix tree now that most likely means that someone besides DAX is inserting pages (which has happened lots of times in the past), and we want to find that out early and fail loudly. This solution also removes the extra memory consumption. Here is that same /proc/[pid]/smaps after 1GiB of reading from a hole with the new code: 7f2054a74000-7f2094a74000 rw-s 00000000 103:00 12 /root/dax/data Size: 1048576 kB Rss: 0 kB Pss: 0 kB Shared_Clean: 0 kB Shared_Dirty: 0 kB Private_Clean: 0 kB Private_Dirty: 0 kB Referenced: 0 kB Anonymous: 0 kB LazyFree: 0 kB AnonHugePages: 0 kB ShmemPmdMapped: 0 kB Shared_Hugetlb: 0 kB Private_Hugetlb: 0 kB Swap: 0 kB SwapPss: 0 kB KernelPageSize: 4 kB MMUPageSize: 4 kB Locked: 0 kB Overall system memory consumption is similarly improved. Another major change is that we remove dax_pfn_mkwrite() from our fault flow, and instead rely on the page fault itself to make the PTE dirty and writeable. The following description from the patch adding the vm_insert_mixed_mkwrite() call explains this a little more: "To be able to use the common 4k zero page in DAX we need to have our PTE fault path look more like our PMD fault path where a PTE entry can be marked as dirty and writeable as it is first inserted rather than waiting for a follow-up dax_pfn_mkwrite() => finish_mkwrite_fault() call. Right now we can rely on having a dax_pfn_mkwrite() call because we can distinguish between these two cases in do_wp_page(): case 1: 4k zero page => writable DAX storage case 2: read-only DAX storage => writeable DAX storage This distinction is made by via vm_normal_page(). vm_normal_page() returns false for the common 4k zero page, though, just as it does for DAX ptes. Instead of special casing the DAX + 4k zero page case we will simplify our DAX PTE page fault sequence so that it matches our DAX PMD sequence, and get rid of the dax_pfn_mkwrite() helper. We will instead use dax_iomap_fault() to handle write-protection faults. This means that insert_pfn() needs to follow the lead of insert_pfn_pmd() and allow us to pass in a 'mkwrite' flag. If 'mkwrite' is set insert_pfn() will do the work that was previously done by wp_page_reuse() as part of the dax_pfn_mkwrite() call path" Link: http://lkml.kernel.org/r/20170724170616.25810-4-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-05ext4: fix null pointer dereference on sbiColin Ian King1-1/+1
In the case of a kzalloc failure when allocating sbi we end up with a null pointer dereference on sbi when assigning sbi->s_daxdev. Fix this by moving the assignment of sbi->s_daxdev to after the null pointer check of sbi. Detected by CoverityScan CID#1455379 ("Dereference before null check") Fixes: 5e405595e5bf ("ext4: perform dax_device lookup at mount") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>