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2022-10-28mm/shmem: ensure proper fallback if page faultsIra Weiny1-0/+17
The kernel test robot flagged a recursive lock as a result of a conversion from kmap_atomic() to kmap_local_folio()[Link] The cause was due to the code depending on the kmap_atomic() side effect of disabling page faults. In that case the code expects the fault to fail and take the fallback case. git archaeology implied that the recursion may not be an actual bug.[1] However, depending on the implementation of the mmap_lock and the condition of the call there may still be a deadlock.[2] So this is not purely a lockdep issue. Considering a single threaded call stack there are 3 options. 1) Different mm's are in play (no issue) 2) Readlock implementation is recursive and same mm is in play (no issue) 3) Readlock implementation is _not_ recursive (issue) The mmap_lock is recursive so with a single thread there is no issue. However, Matthew pointed out a deadlock scenario when you consider additional process' and threads thusly. "The readlock implementation is only recursive if nobody else has taken a write lock. If you have a multithreaded process, one of the other threads can call mmap() and that will prevent recursion (due to fairness). Even if it's a different process that you're trying to acquire the mmap read lock on, you can still get into a deadly embrace. eg: process A thread 1 takes read lock on own mmap_lock process A thread 2 calls mmap, blocks taking write lock process B thread 1 takes page fault, read lock on own mmap lock process B thread 2 calls mmap, blocks taking write lock process A thread 1 blocks taking read lock on process B process B thread 1 blocks taking read lock on process A Now all four threads are blocked waiting for each other." Regardless using pagefault_disable() ensures that no matter what locking implementation is used a deadlock will not occur. Add an explicit pagefault_disable() and a big comment to explain this for future souls looking at this code. [1] https://lore.kernel.org/all/Y1MymJ%2FINb45AdaY@iweiny-desk3/ [2] https://lore.kernel.org/lkml/Y1bXBtGTCym77%2FoD@casper.infradead.org/ Link: https://lkml.kernel.org/r/20221025220108.2366043-1-ira.weiny@intel.com Link: https://lore.kernel.org/r/202210211215.9dc6efb5-yujie.liu@intel.com Fixes: 7a7256d5f512 ("shmem: convert shmem_mfill_atomic_pte() to use a folio") Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reported-by: kernel test robot <yujie.liu@intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-11treewide: use get_random_u32() when possibleJason A. Donenfeld1-1/+1
The prandom_u32() function has been a deprecated inline wrapper around get_random_u32() for several releases now, and compiles down to the exact same code. Replace the deprecated wrapper with a direct call to the real function. The same also applies to get_random_int(), which is just a wrapper around get_random_u32(). This was done as a basic find and replace. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Acked-by: Helge Deller <deller@gmx.de> # for parisc Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-10Merge tag 'pull-tmpfile' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-3/+3
Pull vfs tmpfile updates from Al Viro: "Miklos' ->tmpfile() signature change; pass an unopened struct file to it, let it open the damn thing. Allows to add tmpfile support to FUSE" * tag 'pull-tmpfile' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fuse: implement ->tmpfile() vfs: open inside ->tmpfile() vfs: move open right after ->tmpfile() vfs: make vfs_tmpfile() static ovl: use vfs_tmpfile_open() helper cachefiles: use vfs_tmpfile_open() helper cachefiles: only pass inode to *mark_inode_inuse() helpers cachefiles: tmpfile error handling cleanup hugetlbfs: cleanup mknod and tmpfile vfs: add vfs_tmpfile_open() helper
2022-10-03mm/shmem: add flag to enforce shmem THP in hugepage_vma_check()Zach O'Keefe1-8/+10
Patch series "mm: add file/shmem support to MADV_COLLAPSE", v4. This series builds on top of the previous "mm: userspace hugepage collapse" series which introduced the MADV_COLLAPSE madvise mode and added support for private, anonymous mappings[2], by adding support for file and shmem backed memory to CONFIG_READ_ONLY_THP_FOR_FS=y kernels. File and shmem support have been added with effort to align with existing MADV_COLLAPSE semantics and policy decisions[3]. Collapse of shmem-backed memory ignores kernel-guiding directives and heuristics including all sysfs settings (transparent_hugepage/shmem_enabled), and tmpfs huge= mount options (shmem always supports large folios). Like anonymous mappings, on successful return of MADV_COLLAPSE on file/shmem memory, the contents of memory mapped by the addresses provided will be synchronously pmd-mapped THPs. This functionality unlocks two important uses: (1) Immediately back executable text by THPs. Current support provided by CONFIG_READ_ONLY_THP_FOR_FS may take a long time on a large system which might impair services from serving at their full rated load after (re)starting. Tricks like mremap(2)'ing text onto anonymous memory to immediately realize iTLB performance prevents page sharing and demand paging, both of which increase steady state memory footprint. Now, we can have the best of both worlds: Peak upfront performance and lower RAM footprints. (2) userfaultfd-based live migration of virtual machines satisfy UFFD faults by fetching native-sized pages over the network (to avoid latency of transferring an entire hugepage). However, after guest memory has been fully copied to the new host, MADV_COLLAPSE can be used to immediately increase guest performance. khugepaged has received a small improvement by association and can now detect and collapse pte-mapped THPs. However, there is still work to be done along the file collapse path. Compound pages of arbitrary order still needs to be supported and THP collapse needs to be converted to using folios in general. Eventually, we'd like to move away from the read-only and executable-mapped constraints currently imposed on eligible files and support any inode claiming huge folio support. That said, I think the series as-is covers enough to claim that MADV_COLLAPSE supports file/shmem memory. Patches 1-3 Implement the guts of the series. Patch 4 Is a tracepoint for debugging. Patches 5-9 Refactor existing khugepaged selftests to work with new memory types + new collapse tests. Patch 10 Adds a userfaultfd selftest mode to mimic a functional test of UFFDIO_REGISTER_MODE_MINOR+MADV_COLLAPSE live migration. (v4 note: "userfaultfd shmem" selftest is failing as of Sep 22 mm-unstable) [1] https://lore.kernel.org/linux-mm/YyiK8YvVcrtZo0z3@google.com/ [2] https://lore.kernel.org/linux-mm/20220706235936.2197195-1-zokeefe@google.com/ [3] https://lore.kernel.org/linux-mm/YtBmhaiPHUTkJml8@google.com/ [4] https://lore.kernel.org/linux-mm/20220922222731.1124481-1-zokeefe@google.com/ [5] https://lore.kernel.org/linux-mm/20220922184651.1016461-1-zokeefe@google.com/ This patch (of 10): Extend 'mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()' to shmem, allowing callers to ignore /sys/kernel/transparent_hugepage/shmem_enabled and tmpfs huge= mount. This is intended to be used by MADV_COLLAPSE, and the rationale is analogous to the anon/file case: MADV_COLLAPSE is not coupled to directives that advise the kernel's decisions on when THPs should be considered eligible. shmem/tmpfs always claims large folio support, regardless of sysfs or mount options. [shy828301@gmail.com: test shmem_huge_force explicitly] Link: https://lore.kernel.org/linux-mm/CAHbLzko3A5-TpS0BgBeKkx5cuOkWgLvWXQH=TdgW-baO4rPtdg@mail.gmail.com/ Link: https://lkml.kernel.org/r/20220922224046.1143204-1-zokeefe@google.com Link: https://lkml.kernel.org/r/20220907144521.3115321-2-zokeefe@google.com Link: https://lkml.kernel.org/r/20220922224046.1143204-2-zokeefe@google.com Signed-off-by: Zach O'Keefe <zokeefe@google.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Chris Kennelly <ckennelly@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Houghton <jthoughton@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03tmpfs: add support for an i_version counterJeff Layton1-3/+28
NFSv4 mandates a change attribute to avoid problems with timestamp granularity, which Linux implements using the i_version counter. This is particularly important when the underlying filesystem is fast. Give tmpfs an i_version counter. Since it doesn't have to be persistent, we can just turn on SB_I_VERSION and sprinkle some inode_inc_iversion calls in the right places. Also, while there is no formal spec for xattrs, most implementations update the ctime on setxattr. Fix shmem_xattr_handler_set to update the ctime and bump the i_version appropriately. Link: https://lkml.kernel.org/r/20220909130031.15477-1-jlayton@kernel.org Signed-off-by: Jeff Layton <jlayton@kernel.org> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: remove shmem_getpage()Matthew Wilcox (Oracle)1-14/+1
With all callers removed, remove this wrapper function. The flags are now mysteriously called SGP, but I think we can live with that. Link: https://lkml.kernel.org/r/20220902194653.1739778-34-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03khugepaged: call shmem_get_folio()Matthew Wilcox (Oracle)1-2/+2
shmem_getpage() is being removed, so call its replacement and find the precise page ourselves. Link: https://lkml.kernel.org/r/20220902194653.1739778-32-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_get_link() to use a folioMatthew Wilcox (Oracle)1-16/+17
Symlinks will never use a large folio, but using the folio API removes a lot of unnecessary folio->page->folio conversions. Link: https://lkml.kernel.org/r/20220902194653.1739778-31-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_symlink() to use a folioMatthew Wilcox (Oracle)1-7/+7
While symlinks will always be < PAGE_SIZE, using the folio APIs gets rid of unnecessary calls to compound_head(). Link: https://lkml.kernel.org/r/20220902194653.1739778-30-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_fallocate() to use a folioMatthew Wilcox (Oracle)1-19/+17
Call shmem_get_folio() and use the folio APIs instead of the page APIs. Saves several calls to compound_head() and removes assumptions about the size of a large folio. Link: https://lkml.kernel.org/r/20220902194653.1739778-29-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_file_read_iter() to use shmem_get_folio()Matthew Wilcox (Oracle)1-9/+11
Use a folio throughout, saving five calls to compound_head(). Link: https://lkml.kernel.org/r/20220902194653.1739778-28-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_write_begin() to use shmem_get_folio()Matthew Wilcox (Oracle)1-3/+5
Use a folio throughout this function, saving a couple of calls to compound_head(). Link: https://lkml.kernel.org/r/20220902194653.1739778-27-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_get_partial_folio() to use shmem_get_folio()Matthew Wilcox (Oracle)1-5/+4
Get rid of an unnecessary folio->page->folio conversion. Link: https://lkml.kernel.org/r/20220902194653.1739778-26-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: add shmem_get_folio()Matthew Wilcox (Oracle)1-13/+10
With no remaining callers of shmem_getpage_gfp(), add shmem_get_folio() and reimplement shmem_getpage() as a call to shmem_get_folio(). Link: https://lkml.kernel.org/r/20220902194653.1739778-25-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_read_mapping_page_gfp() to use shmem_get_folio_gfp()Matthew Wilcox (Oracle)1-3/+5
Saves a couple of calls to compound_head(). Link: https://lkml.kernel.org/r/20220902194653.1739778-24-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_fault() to use shmem_get_folio_gfp()Matthew Wilcox (Oracle)1-1/+4
No particular advantage for this function, but necessary to remove shmem_getpage_gfp(). [hughd@google.com: fix crash] Link: https://lkml.kernel.org/r/7693a84-bdc2-27b5-2695-d0fe8566571f@google.com Link: https://lkml.kernel.org/r/20220902194653.1739778-23-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_getpage_gfp() to shmem_get_folio_gfp()Matthew Wilcox (Oracle)1-29/+41
Add a shmem_getpage_gfp() wrapper for compatibility with current users. Link: https://lkml.kernel.org/r/20220902194653.1739778-22-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: eliminate struct page from shmem_swapin_folio()Matthew Wilcox (Oracle)1-8/+8
Convert shmem_swapin() to return a folio and use swap_cache_get_folio(), removing all uses of struct page in this function. Link: https://lkml.kernel.org/r/20220902194653.1739778-21-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_replace_page() to shmem_replace_folio()Matthew Wilcox (Oracle)1-5/+4
The caller has a folio, so convert the calling convention and rename the function. Link: https://lkml.kernel.org/r/20220902194653.1739778-19-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_mfill_atomic_pte() to use a folioMatthew Wilcox (Oracle)1-26/+19
Assert that this is a single-page folio as there are several assumptions in here that it's exactly PAGE_SIZE bytes large. Saves several calls to compound_head() and removes the last caller of shmem_alloc_page(). Link: https://lkml.kernel.org/r/20220902194653.1739778-18-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm/swap: convert put_swap_page() to put_swap_folio()Matthew Wilcox (Oracle)1-1/+1
With all callers now using a folio, we can convert this function. Link: https://lkml.kernel.org/r/20220902194653.1739778-14-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm/swap: convert add_to_swap_cache() to take a folioMatthew Wilcox (Oracle)1-1/+1
With all callers using folios, we can convert add_to_swap_cache() to take a folio and use it throughout. Link: https://lkml.kernel.org/r/20220902194653.1739778-13-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_replace_page() to use folios throughoutMatthew Wilcox (Oracle)1-35/+32
Introduce folio_set_swap_entry() to abstract how both folio->private and swp_entry_t work. Use swap_address_space() directly instead of indirecting through folio_mapping(). Include an assertion that the old folio is not large as we only allocate a single-page folio to replace it. Use folio_put_refs() instead of calling folio_put() twice. Link: https://lkml.kernel.org/r/20220902194653.1739778-9-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_delete_from_page_cache() to take a folioMatthew Wilcox (Oracle)1-12/+11
Remove the assertion that the page is not Compound as this function now handles large folios correctly. Link: https://lkml.kernel.org/r/20220902194653.1739778-8-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03shmem: convert shmem_writepage() to use a folio throughoutMatthew Wilcox (Oracle)1-23/+24
Even though we will split any large folio that comes in, write the code to handle large folios so as to not leave a trap for whoever tries to handle large folios in the swap cache. Link: https://lkml.kernel.org/r/20220902194653.1739778-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm: add split_folio()Matthew Wilcox (Oracle)1-1/+1
This wrapper removes a need to use split_huge_page(&folio->page). Convert two callers. Link: https://lkml.kernel.org/r/20220902194653.1739778-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-24vfs: open inside ->tmpfile()Miklos Szeredi1-3/+3
This is in preparation for adding tmpfile support to fuse, which requires that the tmpfile creation and opening are done as a single operation. Replace the 'struct dentry *' argument of i_op->tmpfile with 'struct file *'. Call finish_open_simple() as the last thing in ->tmpfile() instances (may be omitted in the error case). Change d_tmpfile() argument to 'struct file *' as well to make callers more readable. Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2022-08-28shmem: update folio if shmem_replace_page() updates the pageMatthew Wilcox (Oracle)1-0/+1
If we allocate a new page, we need to make sure that our folio matches that new page. If we do end up in this code path, we store the wrong page in the shmem inode's page cache, and I would rather imagine that data corruption ensues. This will be solved by changing shmem_replace_page() to shmem_replace_folio(), but this is the minimal fix. Link: https://lkml.kernel.org/r/20220730042518.1264767-1-willy@infradead.org Fixes: da08e9b79323 ("mm/shmem: convert shmem_swapin_page() to shmem_swapin_folio()") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-20mm/shmem: shmem_replace_page() remember NR_SHMEMHugh Dickins1-0/+2
Elsewhere, NR_SHMEM is updated at the same time as shmem NR_FILE_PAGES; but shmem_replace_page() was forgetting to do that - so NR_SHMEM stats could grow too big or too small, in those unusual cases when it's used. Link: https://lkml.kernel.org/r/cec7c09d-5874-e160-ada6-6e10ee48784@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Radoslaw Burny <rburny@google.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-20mm/shmem: tmpfs fallocate use file_modified()Hugh Dickins1-1/+2
5.18 fixed the btrfs and ext4 fallocates to use file_modified(), as xfs was already doing, to drop privileges: and fstests generic/{683,684,688} expect this. There's no need to argue over keep-size allocation (which could just update ctime): fix shmem_fallocate() to behave the same way. Link: https://lkml.kernel.org/r/39c5e62-4896-7795-c0a0-f79c50d4909@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Radoslaw Burny <rburny@google.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-20mm/shmem: fix chattr fsflags support in tmpfsHugh Dickins1-23/+31
ext[234] have always allowed unimplemented chattr flags to be set, but other filesystems have tended to be stricter. Follow the stricter approach for tmpfs: I don't want to have to explain why csu attributes don't actually work, and we won't need to update the chattr(1) manpage; and it's never wrong to start off strict, relaxing later if persuaded. Allow only a (append only) i (immutable) A (no atime) and d (no dump). Although lsattr showed 'A' inherited, the NOATIME behavior was not being inherited: because nothing sync'ed FS_NOATIME_FL to S_NOATIME. Add shmem_set_inode_flags() to sync the flags, using inode_set_flags() to avoid that instant of lost immutablility during fileattr_set(). But that change switched generic/079 from passing to failing: because FS_IMMUTABLE_FL and FS_APPEND_FL had been unconventionally included in the INHERITED fsflags: remove them and generic/079 is back to passing. Link: https://lkml.kernel.org/r/2961dcb0-ddf3-b9f0-3268-12a4ff996856@google.com Fixes: e408e695f5f1 ("mm/shmem: support FS_IOC_[SG]ETFLAGS in tmpfs") Signed-off-by: Hugh Dickins <hughd@google.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Radoslaw Burny <rburny@google.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08Merge tag 'pull-work.iov_iter-rebased' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-1/+1
Pull more iov_iter updates from Al Viro: - more new_sync_{read,write}() speedups - ITER_UBUF introduction - ITER_PIPE cleanups - unification of iov_iter_get_pages/iov_iter_get_pages_alloc and switching them to advancing semantics - making ITER_PIPE take high-order pages without splitting them - handling copy_page_from_iter() for high-order pages properly * tag 'pull-work.iov_iter-rebased' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits) fix copy_page_from_iter() for compound destinations hugetlbfs: copy_page_to_iter() can deal with compound pages copy_page_to_iter(): don't split high-order page in case of ITER_PIPE expand those iov_iter_advance()... pipe_get_pages(): switch to append_pipe() get rid of non-advancing variants ceph: switch the last caller of iov_iter_get_pages_alloc() 9p: convert to advancing variant of iov_iter_get_pages_alloc() af_alg_make_sg(): switch to advancing variant of iov_iter_get_pages() iter_to_pipe(): switch to advancing variant of iov_iter_get_pages() block: convert to advancing variants of iov_iter_get_pages{,_alloc}() iov_iter: advancing variants of iov_iter_get_pages{,_alloc}() iov_iter: saner helper for page array allocation fold __pipe_get_pages() into pipe_get_pages() ITER_XARRAY: don't open-code DIV_ROUND_UP() unify the rest of iov_iter_get_pages()/iov_iter_get_pages_alloc() guts unify xarray_get_pages() and xarray_get_pages_alloc() unify pipe_get_pages() and pipe_get_pages_alloc() iov_iter_get_pages(): sanity-check arguments iov_iter_get_pages_alloc(): lift freeing pages array on failure exits into wrapper ...
2022-08-08new iov_iter flavour - ITER_UBUFAl Viro1-1/+1
Equivalent of single-segment iovec. Initialized by iov_iter_ubuf(), checked for by iter_is_ubuf(), otherwise behaves like ITER_IOVEC ones. We are going to expose the things like ->write_iter() et.al. to those in subsequent commits. New predicate (user_backed_iter()) that is true for ITER_IOVEC and ITER_UBUF; places like direct-IO handling should use that for checking that pages we modify after getting them from iov_iter_get_pages() would need to be dirtied. DO NOT assume that replacing iter_is_iovec() with user_backed_iter() will solve all problems - there's code that uses iter_is_iovec() to decide how to poke around in iov_iter guts and for that the predicate replacement obviously won't suffice. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-05Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds1-8/+70
Pull MM updates from Andrew Morton: "Most of the MM queue. A few things are still pending. Liam's maple tree rework didn't make it. This has resulted in a few other minor patch series being held over for next time. Multi-gen LRU still isn't merged as we were waiting for mapletree to stabilize. The current plan is to merge MGLRU into -mm soon and to later reintroduce mapletree, with a view to hopefully getting both into 6.1-rc1. Summary: - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe Lin, Yang Shi, Anshuman Khandual and Mike Rapoport - Some kmemleak fixes from Patrick Wang and Waiman Long - DAMON updates from SeongJae Park - memcg debug/visibility work from Roman Gushchin - vmalloc speedup from Uladzislau Rezki - more folio conversion work from Matthew Wilcox - enhancements for coherent device memory mapping from Alex Sierra - addition of shared pages tracking and CoW support for fsdax, from Shiyang Ruan - hugetlb optimizations from Mike Kravetz - Mel Gorman has contributed some pagealloc changes to improve latency and realtime behaviour. - mprotect soft-dirty checking has been improved by Peter Xu - Many other singleton patches all over the place" [ XFS merge from hell as per Darrick Wong in https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ] * tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits) tools/testing/selftests/vm/hmm-tests.c: fix build mm: Kconfig: fix typo mm: memory-failure: convert to pr_fmt() mm: use is_zone_movable_page() helper hugetlbfs: fix inaccurate comment in hugetlbfs_statfs() hugetlbfs: cleanup some comments in inode.c hugetlbfs: remove unneeded header file hugetlbfs: remove unneeded hugetlbfs_ops forward declaration hugetlbfs: use helper macro SZ_1{K,M} mm: cleanup is_highmem() mm/hmm: add a test for cross device private faults selftests: add soft-dirty into run_vmtests.sh selftests: soft-dirty: add test for mprotect mm/mprotect: fix soft-dirty check in can_change_pte_writable() mm: memcontrol: fix potential oom_lock recursion deadlock mm/gup.c: fix formatting in check_and_migrate_movable_page() xfs: fail dax mount if reflink is enabled on a partition mm/memcontrol.c: remove the redundant updating of stats_flush_threshold userfaultfd: don't fail on unrecognized features hugetlb_cgroup: fix wrong hugetlb cgroup numa stat ...
2022-08-03Merge tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecacheLinus Torvalds1-10/+9
Pull folio updates from Matthew Wilcox: - Fix an accounting bug that made NR_FILE_DIRTY grow without limit when running xfstests - Convert more of mpage to use folios - Remove add_to_page_cache() and add_to_page_cache_locked() - Convert find_get_pages_range() to filemap_get_folios() - Improvements to the read_cache_page() family of functions - Remove a few unnecessary checks of PageError - Some straightforward filesystem conversions to use folios - Split PageMovable users out from address_space_operations into their own movable_operations - Convert aops->migratepage to aops->migrate_folio - Remove nobh support (Christoph Hellwig) * tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache: (78 commits) fs: remove the NULL get_block case in mpage_writepages fs: don't call ->writepage from __mpage_writepage fs: remove the nobh helpers jfs: stop using the nobh helper ext2: remove nobh support ntfs3: refactor ntfs_writepages mm/folio-compat: Remove migration compatibility functions fs: Remove aops->migratepage() secretmem: Convert to migrate_folio hugetlb: Convert to migrate_folio aio: Convert to migrate_folio f2fs: Convert to filemap_migrate_folio() ubifs: Convert to filemap_migrate_folio() btrfs: Convert btrfs_migratepage to migrate_folio mm/migrate: Add filemap_migrate_folio() mm/migrate: Convert migrate_page() to migrate_folio() nfs: Convert to migrate_folio btrfs: Convert btree_migratepage to migrate_folio mm/migrate: Convert expected_page_refs() to folio_expected_refs() mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio() ...
2022-08-02mm/migrate: Convert migrate_page() to migrate_folio()Matthew Wilcox (Oracle)1-1/+1
Convert all callers to pass a folio. Most have the folio already available. Switch all users from aops->migratepage to aops->migrate_folio. Also turn the documentation into kerneldoc. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: David Sterba <dsterba@suse.com>
2022-07-29mm/shmem: support FS_IOC_[SG]ETFLAGS in tmpfsTheodore Ts'o1-1/+63
This allows userspace to set flags like FS_APPEND_FL, FS_IMMUTABLE_FL, FS_NODUMP_FL, etc., like all other standard Linux file systems. [akpm@linux-foundation.org: fix CONFIG_TMPFS_XATTR=n warnings] Link: https://lkml.kernel.org/r/20220715015912.2560575-1-tytso@mit.edu Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-18tmpfs: fix the issue that the mount and remount results are inconsistent.ZhaoLong Wang1-5/+2
An undefined-behavior issue has not been completely fixed since commit d14f5efadd84 ("tmpfs: fix undefined-behaviour in shmem_reconfigure()"). In the commit, check in the shmem_reconfigure() is added in remount process to avoid the Ubsan problem. However, the check is not added to the mount process. It causes inconsistent results between mount and remount. The operations to reproduce the problem in user mode as follows: If nr_blocks is set to 0x8000000000000000, the mounting is successful. # mount tmpfs /dev/shm/ -t tmpfs -o nr_blocks=0x8000000000000000 However, when -o remount is used, the mount fails because of the check in the shmem_reconfigure() # mount tmpfs /dev/shm/ -t tmpfs -o remount,nr_blocks=0x8000000000000000 mount: /dev/shm: mount point not mounted or bad option. Therefore, add checks in the shmem_parse_one() function and remove the check in shmem_reconfigure() to avoid this problem. Link: https://lkml.kernel.org/r/20220629124324.1640807-1-wangzhaolong1@huawei.com Signed-off-by: ZhaoLong Wang <wangzhaolong1@huawei.com> Cc: Luo Meng <luomeng12@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: Yu Kuai <yukuai3@huawei.com> Cc: Zhihao Cheng <chengzhihao1@huawei.com> Cc: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03mm/swap: convert delete_from_swap_cache() to take a folioMatthew Wilcox (Oracle)1-2/+2
All but one caller already has a folio, so convert it to use a folio. Link: https://lkml.kernel.org/r/20220617175020.717127-22-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-29shmem: Convert shmem_unlock_mapping() to use filemap_get_folios()Matthew Wilcox (Oracle)1-7/+6
This is a straightforward conversion. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-06-29filemap: Remove add_to_page_cache() and add_to_page_cache_locked()Matthew Wilcox (Oracle)1-1/+1
These functions have no more users, so delete them. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com>
2022-06-29mm: Remove __delete_from_page_cache()Matthew Wilcox (Oracle)1-1/+1
This wrapper is no longer used. Remove it and all references to it. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-06-16mm/shmem.c: clean up comment of shmem_swapin_folioMiaohe Lin1-5/+5
shmem_swapin_folio has changed to use folio but comment still mentions page. Update the relevant comment accordingly as suggested by Naoya. Link: https://lkml.kernel.org/r/20220530115841.4348-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Suggested-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-27Merge tag 'mm-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds1-1/+40
Pull more MM updates from Andrew Morton: - Two follow-on fixes for the post-5.19 series "Use pageblock_order for cma and alloc_contig_range alignment", from Zi Yan. - A series of z3fold cleanups and fixes from Miaohe Lin. - Some memcg selftests work from Michal Koutný <mkoutny@suse.com> - Some swap fixes and cleanups from Miaohe Lin - Several individual minor fixups * tag 'mm-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (25 commits) mm/shmem.c: suppress shift warning mm: Kconfig: reorganize misplaced mm options mm: kasan: fix input of vmalloc_to_page() mm: fix is_pinnable_page against a cma page mm: filter out swapin error entry in shmem mapping mm/shmem: fix infinite loop when swap in shmem error at swapoff time mm/madvise: free hwpoison and swapin error entry in madvise_free_pte_range mm/swapfile: fix lost swap bits in unuse_pte() mm/swapfile: unuse_pte can map random data if swap read fails selftests: memcg: factor out common parts of memory.{low,min} tests selftests: memcg: remove protection from top level memcg selftests: memcg: adjust expected reclaim values of protected cgroups selftests: memcg: expect no low events in unprotected sibling selftests: memcg: fix compilation mm/z3fold: fix z3fold_page_migrate races with z3fold_map mm/z3fold: fix z3fold_reclaim_page races with z3fold_free mm/z3fold: always clear PAGE_CLAIMED under z3fold page lock mm/z3fold: put z3fold page back into unbuddied list when reclaim or migration fails revert "mm/z3fold.c: allow __GFP_HIGHMEM in z3fold_alloc" mm/z3fold: throw warning on failure of trylock_page in z3fold_alloc ...
2022-05-27mm/shmem.c: suppress shift warningAndrew Morton1-1/+1
mm/shmem.c:1948 shmem_getpage_gfp() warn: should '(((1) << 12) / 512) << folio_order(folio)' be a 64 bit type? On i386, so an unsigned long is 32-bit, but i_blocks is a 64-bit blkcnt_t. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Jessica Clarke <jrtc27@jrtc27.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-27mm/shmem: fix infinite loop when swap in shmem error at swapoff timeMiaohe Lin1-0/+39
When swap in shmem error at swapoff time, there would be a infinite loop in the while loop in shmem_unuse_inode(). It's because swapin error is deliberately ignored now and thus info->swapped will never reach 0. So we can't escape the loop in shmem_unuse(). In order to fix the issue, swapin_error entry is stored in the mapping when swapin error occurs. So the swapcache page can be freed and the user won't end up with a permanently mounted swap because a sector is bad. If the page is accessed later, the user process will be killed so that corrupted data is never consumed. On the other hand, if the page is never accessed, the user won't even notice it. Link: https://lkml.kernel.org/r/20220519125030.21486-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reported-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: NeilBrown <neilb@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-26Merge tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds1-185/+168
Pull MM updates from Andrew Morton: "Almost all of MM here. A few things are still getting finished off, reviewed, etc. - Yang Shi has improved the behaviour of khugepaged collapsing of readonly file-backed transparent hugepages. - Johannes Weiner has arranged for zswap memory use to be tracked and managed on a per-cgroup basis. - Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime enablement of the recent huge page vmemmap optimization feature. - Baolin Wang contributes a series to fix some issues around hugetlb pagetable invalidation. - Zhenwei Pi has fixed some interactions between hwpoisoned pages and virtualization. - Tong Tiangen has enabled the use of the presently x86-only page_table_check debugging feature on arm64 and riscv. - David Vernet has done some fixup work on the memcg selftests. - Peter Xu has taught userfaultfd to handle write protection faults against shmem- and hugetlbfs-backed files. - More DAMON development from SeongJae Park - adding online tuning of the feature and support for monitoring of fixed virtual address ranges. Also easier discovery of which monitoring operations are available. - Nadav Amit has done some optimization of TLB flushing during mprotect(). - Neil Brown continues to labor away at improving our swap-over-NFS support. - David Hildenbrand has some fixes to anon page COWing versus get_user_pages(). - Peng Liu fixed some errors in the core hugetlb code. - Joao Martins has reduced the amount of memory consumed by device-dax's compound devmaps. - Some cleanups of the arch-specific pagemap code from Anshuman Khandual. - Muchun Song has found and fixed some errors in the TLB flushing of transparent hugepages. - Roman Gushchin has done more work on the memcg selftests. ... and, of course, many smaller fixes and cleanups. Notably, the customary million cleanup serieses from Miaohe Lin" * tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits) mm: kfence: use PAGE_ALIGNED helper selftests: vm: add the "settings" file with timeout variable selftests: vm: add "test_hmm.sh" to TEST_FILES selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests selftests: vm: add migration to the .gitignore selftests/vm/pkeys: fix typo in comment ksm: fix typo in comment selftests: vm: add process_mrelease tests Revert "mm/vmscan: never demote for memcg reclaim" mm/kfence: print disabling or re-enabling message include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace" include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion" mm: fix a potential infinite loop in start_isolate_page_range() MAINTAINERS: add Muchun as co-maintainer for HugeTLB zram: fix Kconfig dependency warning mm/shmem: fix shmem folio swapoff hang cgroup: fix an error handling path in alloc_pagecache_max_30M() mm: damon: use HPAGE_PMD_SIZE tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate nodemask.h: fix compilation error with GCC12 ...
2022-05-25mm/shmem: fix shmem folio swapoff hangHugh Dickins1-2/+1
Shmem swapoff makes no progress: the index to indices is not incremented. But "ret" is no longer a return value, so use folio_batch_count() instead. Link: https://lkml.kernel.org/r/c32bee8a-f0aa-245-f94e-24dd271924fa@google.com Fixes: da08e9b79323 ("mm/shmem: convert shmem_swapin_page() to shmem_swapin_folio()") Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Tested-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19tmpfs: fix undefined-behaviour in shmem_reconfigure()Luo Meng1-0/+4
When shmem_reconfigure() calls __percpu_counter_compare(), the second parameter is unsigned long long. But in the definition of __percpu_counter_compare(), the second parameter is s64. So when __percpu_counter_compare() executes abs(count - rhs), UBSAN shows the following warning: ================================================================================ UBSAN: Undefined behaviour in lib/percpu_counter.c:209:6 signed integer overflow: 0 - -9223372036854775808 cannot be represented in type 'long long int' CPU: 1 PID: 9636 Comm: syz-executor.2 Tainted: G ---------r- - 4.18.0 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Call Trace: __dump_stack home/install/linux-rh-3-10/lib/dump_stack.c:77 [inline] dump_stack+0x125/0x1ae home/install/linux-rh-3-10/lib/dump_stack.c:117 ubsan_epilogue+0xe/0x81 home/install/linux-rh-3-10/lib/ubsan.c:159 handle_overflow+0x19d/0x1ec home/install/linux-rh-3-10/lib/ubsan.c:190 __percpu_counter_compare+0x124/0x140 home/install/linux-rh-3-10/lib/percpu_counter.c:209 percpu_counter_compare home/install/linux-rh-3-10/./include/linux/percpu_counter.h:50 [inline] shmem_remount_fs+0x1ce/0x6b0 home/install/linux-rh-3-10/mm/shmem.c:3530 do_remount_sb+0x11b/0x530 home/install/linux-rh-3-10/fs/super.c:888 do_remount home/install/linux-rh-3-10/fs/namespace.c:2344 [inline] do_mount+0xf8d/0x26b0 home/install/linux-rh-3-10/fs/namespace.c:2844 ksys_mount+0xad/0x120 home/install/linux-rh-3-10/fs/namespace.c:3075 __do_sys_mount home/install/linux-rh-3-10/fs/namespace.c:3089 [inline] __se_sys_mount home/install/linux-rh-3-10/fs/namespace.c:3086 [inline] __x64_sys_mount+0xbf/0x160 home/install/linux-rh-3-10/fs/namespace.c:3086 do_syscall_64+0xca/0x5c0 home/install/linux-rh-3-10/arch/x86/entry/common.c:298 entry_SYSCALL_64_after_hwframe+0x6a/0xdf RIP: 0033:0x46b5e9 Code: 5d db fa ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b db fa ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f54d5f22c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000077bf60 RCX: 000000000046b5e9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000000 RBP: 000000000077bf60 R08: 0000000020000140 R09: 0000000000000000 R10: 00000000026740a4 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd1fb1592f R14: 00007f54d5f239c0 R15: 000000000077bf6c ================================================================================ [akpm@linux-foundation.org: tweak error message text] Link: https://lkml.kernel.org/r/20220513025225.2678727-1-luomeng12@huawei.com Signed-off-by: Luo Meng <luomeng12@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19mm: mmap: register suitable readonly file vmas for khugepagedYang Shi1-4/+0
The readonly FS THP relies on khugepaged to collapse THP for suitable vmas. But the behavior is inconsistent for "always" mode (https://lore.kernel.org/linux-mm/00f195d4-d039-3cf2-d3a1-a2c88de397a0@suse.cz/). The "always" mode means THP allocation should be tried all the time and khugepaged should try to collapse THP all the time. Of course the allocation and collapse may fail due to other factors and conditions. Currently file THP may not be collapsed by khugepaged even though all the conditions are met. That does break the semantics of "always" mode. So make sure readonly FS vmas are registered to khugepaged to fix the break. Register suitable vmas in common mmap path, that could cover both readonly FS vmas and shmem vmas, so remove the khugepaged calls in shmem.c. Still need to keep the khugepaged call in vma_merge() since vma_merge() is called in a lot of places, for example, madvise, mprotect, etc. Link: https://lkml.kernel.org/r/20220510203222.24246-9-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Reported-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Vlastmil Babka <vbabka@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Song Liu <songliubraving@fb.com> Cc: Rik van Riel <riel@surriel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Zi Yan <ziy@nvidia.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Song Liu <song@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>