kernel/linux.git/include/linux/pagemap.h, branch v5.15.209

iov_iter: Introduce fault_in_iov_iter_writeable

2022-05-01T15:22:29+00:00

commit cdd591fc86e38ad3899196066219fbbd845f3162 upstream Introduce a new fault_in_iov_iter_writeable helper for safely faulting in an iterator for writing. Uses get_user_pages() to fault in the pages without actually writing to them, which would be destructive. We'll use fault_in_iov_iter_writeable in gfs2 once we've determined that the iterator passed to .read_iter isn't in memory. Signed-off-by: Andreas Gruenbacher Signed-off-by: Anand Jain Signed-off-by: Greg Kroah-Hartman

gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable}

2022-05-01T15:22:28+00:00

commit bb523b406c849eef8f265a07cd7f320f1f177743 upstream Turn fault_in_pages_{readable,writeable} into versions that return the number of bytes not faulted in, similar to copy_to_user, instead of returning a non-zero value when any of the requested pages couldn't be faulted in. This supports the existing users that require all pages to be faulted in as well as new users that are happy if any pages can be faulted in. Rename the functions to fault_in_{readable,writeable} to make sure this change doesn't silently break things. Neither of these functions is entirely trivial and it doesn't seem useful to inline them, so move them to mm/gup.c. Signed-off-by: Andreas Gruenbacher Signed-off-by: Anand Jain Signed-off-by: Greg Kroah-Hartman

Merge branch 'akpm' (patches from Andrew)

2021-09-08T19:55:35+00:00

Merge more updates from Andrew Morton: "147 patches, based on 7d2a07b769330c34b4deabeed939325c77a7ec2f. Subsystems affected by this patch series: mm (memory-hotplug, rmap, ioremap, highmem, cleanups, secretmem, kfence, damon, and vmscan), alpha, percpu, procfs, misc, core-kernel, MAINTAINERS, lib, checkpatch, epoll, init, nilfs2, coredump, fork, pids, criu, kconfig, selftests, ipc, and scripts" * emailed patches from Andrew Morton : (94 commits) scripts: check_extable: fix typo in user error message mm/workingset: correct kernel-doc notations ipc: replace costly bailout check in sysvipc_find_ipc() selftests/memfd: remove unused variable Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH configs: remove the obsolete CONFIG_INPUT_POLLDEV prctl: allow to setup brk for et_dyn executables pid: cleanup the stale comment mentioning pidmap_init(). kernel/fork.c: unexport get_{mm,task}_exe_file coredump: fix memleak in dump_vma_snapshot() fs/coredump.c: log if a core dump is aborted due to changed file permissions nilfs2: use refcount_dec_and_lock() to fix potential UAF nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group nilfs2: fix NULL pointer in nilfs_##name##_attr_release nilfs2: fix memory leak in nilfs_sysfs_create_device_group trap: cleanup trap_init() init: move usermodehelper_enable() to populate_rootfs() ...

mm: remove redundant compound_head() calling

2021-09-08T18:50:23+00:00

There is a READ_ONCE() in the macro of compound_head(), which will prevent compiler from optimizing the code when there are more than once calling of it in a function. Remove the redundant calling of compound_head() from page_to_index() and page_add_file_rmap() for better code generation. Link: https://lkml.kernel.org/r/20210811101431.83940-1-songmuchun@bytedance.com Signed-off-by: Muchun Song Reviewed-by: David Howells Cc: Matthew Wilcox (Oracle) Cc: William Kucharski Cc: Kirill A. Shutemov Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: change fault_in_pages_* to have an unsigned size parameter

2021-09-03T16:58:13+00:00

fault_in_pages_writeable() and fault_in_pages_readable() treat the size parameter as unsigned, doing pointer math with the value, so make this explicit and set it to be a size_t type which all callers currently treat it as anyway. This solves the issue where static checkers get nervous seeing pointer arithmetic happening with a signed value. Link: https://lkml.kernel.org/r/20210727111136.457638-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman Reported-by: Jordy Zomer Cc: Matthew Wilcox Cc: David Howells Cc: William Kucharski Cc: "Darrick J. Wong" Cc: Hugh Dickins Cc: Mauro Carvalho Chehab Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: move page dirtying prototypes from mm.h

2021-06-29T17:53:48+00:00

These functions implement the address_space ->set_page_dirty operation and should live in pagemap.h, not mm.h so that the rest of the kernel doesn't get funny ideas about calling them directly. Link: https://lkml.kernel.org/r/20210615162342.1669332-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Cc: Al Viro Cc: Dan Williams Cc: Greg Kroah-Hartman Cc: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, futex: fix shared futex pgoff on shmem huge page

2021-06-25T02:40:54+00:00

If more than one futex is placed on a shmem huge page, it can happen that waking the second wakes the first instead, and leaves the second waiting: the key's shared.pgoff is wrong. When 3.11 commit 13d60f4b6ab5 ("futex: Take hugepages into account when generating futex_key"), the only shared huge pages came from hugetlbfs, and the code added to deal with its exceptional page->index was put into hugetlb source. Then that was missed when 4.8 added shmem huge pages. page_to_pgoff() is what others use for this nowadays: except that, as currently written, it gives the right answer on hugetlbfs head, but nonsense on hugetlbfs tails. Fix that by calling hugetlbfs-specific hugetlb_basepage_index() on PageHuge tails as well as on head. Yes, it's unconventional to declare hugetlb_basepage_index() there in pagemap.h, rather than in hugetlb.h; but I do not expect anything but page_to_pgoff() ever to need it. [akpm@linux-foundation.org: give hugetlb_basepage_index() prototype the correct scope] Link: https://lkml.kernel.org/r/b17d946b-d09-326e-b42a-52884c36df32@google.com Fixes: 800d8c63b2e9 ("shmem: add huge pages support") Reported-by: Neel Natu Signed-off-by: Hugh Dickins Reviewed-by: Matthew Wilcox (Oracle) Acked-by: Thomas Gleixner Cc: "Kirill A. Shutemov" Cc: Zhang Yi Cc: Mel Gorman Cc: Mike Kravetz Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Darren Hart Cc: Davidlohr Bueso Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/filemap: fix readahead return types

2021-05-15T02:41:32+00:00

A readahead request will not allocate more memory than can be represented by a size_t, even on systems that have HIGHMEM available. Change the length functions from returning an loff_t to a size_t. Link: https://lkml.kernel.org/r/20210510201201.1558972-1-willy@infradead.org Fixes: 32c0a6bcaa1f57 ("btrfs: add and use readahead_batch_length") Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Darrick J. Wong Reported-by: Linus Torvalds Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: introduce and use mapping_empty()

2021-05-05T18:27:19+00:00

Patch series "Remove nrexceptional tracking", v2. We actually use nrexceptional for very little these days. It's a minor pain to keep in sync with nrpages, but the pain becomes much bigger with the THP patches because we don't know how many indices a shadow entry occupies. It's easier to just remove it than keep it accurate. Also, we save 8 bytes per inode which is nothing to sneeze at; on my laptop, it would improve shmem_inode_cache from 22 to 23 objects per 16kB, and inode_cache from 26 to 27 objects. Combined, that saves a megabyte of memory from a combined usage of 25MB for both caches. Unfortunately, ext4 doesn't cross a magic boundary, so it doesn't save any memory for ext4. This patch (of 4): Instead of checking the two counters (nrpages and nrexceptional), we can just check whether i_pages is empty. Link: https://lkml.kernel.org/r/20201026151849.24232-1-willy@infradead.org Link: https://lkml.kernel.org/r/20201026151849.24232-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Tested-by: Vishal Verma Acked-by: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: move page_mapping_file to pagemap.h

2021-04-30T18:20:37+00:00

page_mapping_file() is only used by some architectures, and then it is usually only used in one place. Make it a static inline function so other architectures don't have to carry this dead code. Link: https://lkml.kernel.org/r/20210317123011.350118-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: David Hildenbrand Acked-by: Mike Rapoport Cc: Huang Ying Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds