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2024-02-21xfs: fix a comment in xfarray.cChristoph Hellwig1-1/+1
xfiles are shmem files, not memfds. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21xfs: remove xfarray_sortinfo.page_kaddrChristoph Hellwig2-19/+4
Now that xfile pages don't need kmapping, there is no need to cache the kernel virtual address for them. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21xfs: add file_{get,put}_folioDarrick J. Wong3-0/+83
Add helper similar to file_{get,set}_page, but which deal with folios and don't allocate new folio unless explicitly asked to, which map to shmem_get_folio instead of calling into the aops. Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21xfs: use shmem_get_folio in in xfile_loadChristoph Hellwig1-35/+26
Switch to using shmem_get_folio in xfile_load instead of using shmem_read_mapping_page_gfp. This gets us support for large folios and also optimized reading from unallocated space, as shmem_get_folio with SGP_READ won't allocate a page for them just to zero the content. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21xfs: use shmem_get_folio in xfile_obj_storeChristoph Hellwig1-46/+27
Switch to using shmem_get_folio and manually dirtying the page instead of abusing aops->write_begin and aops->write_end in xfile_get_page. This simplifies the code by not doing indirect calls of not actually exported interfaces that don't really fit the use case very well, and happens to get us large folio support for free. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21xfs: don't allow highmem pages in xfile mappingsChristoph Hellwig2-14/+10
XFS is generally used on 64-bit, non-highmem platforms and xfile mappings are accessed all the time. Reduce our pain by not allowing any highmem mappings in the xfile page cache and remove all the kmap calls for it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21xfs: don't try to handle non-update pages in xfile_obj_loadChristoph Hellwig1-12/+8
shmem_read_mapping_page_gfp always returns an uptodate page or an ERR_PTR. Remove the code that tries to handle a non-uptodate page. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21xfs: remove the xfile_pread/pwrite APIsChristoph Hellwig5-74/+40
All current and pending xfile users use the xfile_obj_load and xfile_obj_store API, so make those the actual implementation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21xfs: remove xfile_statChristoph Hellwig3-50/+10
vfs_getattr is needed to query inode attributes for unknown underlying file systems. But shmemfs is well known for users of shmem_file_setup and shmem_read_mapping_page_gfp that rely on it not needing specific inode revalidation and having a normal mapping. Remove the detour through the getattr method and an extra wrapper, and just read the inode size and i_bytes directly in the scrub tracing code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21xfs: don't modify file and inode flags for shmem filesChristoph Hellwig1-15/+0
shmem_file_setup is explicitly intended for a file that can be fully read and written by kernel users without restrictions. Don't poke into internals to change random flags in the file or inode. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21xfs: use shmem_kernel_file_setup in xfile_createChristoph Hellwig1-2/+2
shmem_kernel_file_setup is equivalent to shmem_file_setup except that it already sets the S_PRIVATE flag. Use it instead of open coding the logic. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21xfs: shmem_file_setup can't return NULLChristoph Hellwig1-3/+1
shmem_file_setup always returns a struct file pointer or an ERR_PTR, so remove the code to check for a NULL return. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21xfs: use VM_NORESERVE in xfile_createChristoph Hellwig1-1/+1
xfile_create creates a (potentially large) sparse file. Pass VM_NORESERVE to shmem_file_setup to not account for the entire file size at file creation time. Reported-by: Hugh Dickins <hughd@google.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-20xfs: use kvfree in xfs_ioc_getfsmap()Dave Chinner1-1/+1
Another incorrect conversion to kfree() instead of kvfree(). Fixes: 49292576136f ("xfs: convert kmem_free() for kvmalloc users to kvfree()") Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-20xfs: use kvfree() in xfs_ioc_attr_list()Dave Chinner1-1/+1
Wrongly converted from kmem_free() to kfree(). Reported-by: Matthew Wilcox <willy@infradead.org> Fixes: 49292576136f ("xfs: convert kmem_free() for kvmalloc users to kvfree()") Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-19xfs: Remove mrlock wrapperMatthew Wilcox (Oracle)6-94/+18
mrlock was an rwsem wrapper that also recorded whether the lock was held for read or write. Now that we can ask the generic code whether the lock is held for read or write, we can remove this wrapper and use an rwsem directly. As the comment says, we can't use lockdep to assert that the ILOCK is held for write, because we might be in a workqueue, and we aren't able to tell lockdep that we do in fact own the lock. Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-19xfs: Replace xfs_isilocked with xfs_assert_ilockedMatthew Wilcox (Oracle)23-95/+65
To use the new rwsem_assert_held()/rwsem_assert_held_write(), we can't use the existing ASSERT macro. Add a new xfs_assert_ilocked() and convert all the callers. Fix an apparent bug in xfs_isilocked(): If the caller specifies XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL, xfs_assert_ilocked() will check both the IOLOCK and the ILOCK are held for write. xfs_isilocked() only checked that the ILOCK was held for write. xfs_assert_ilocked() is always on, even if DEBUG or XFS_WARN aren't defined. It's a cheap check, so I don't think it's worth defining it away. Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-19xfs: use kvfree for buf in xfs_ioc_getbmapChristoph Hellwig1-1/+1
Without this the kernel crashes in kfree for files with a sufficiently large number of extents. Fixes: d4c75a1b40cd ("xfs: convert remaining kmem_free() to kfree()") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-17xfs: ensure submit buffers on LSN boundaries in error handlersLong Li1-3/+20
While performing the IO fault injection test, I caught the following data corruption report: XFS (dm-0): Internal error ltbno + ltlen > bno at line 1957 of file fs/xfs/libxfs/xfs_alloc.c. Caller xfs_free_ag_extent+0x79c/0x1130 CPU: 3 PID: 33 Comm: kworker/3:0 Not tainted 6.5.0-rc7-next-20230825-00001-g7f8666926889 #214 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 Workqueue: xfs-inodegc/dm-0 xfs_inodegc_worker Call Trace: <TASK> dump_stack_lvl+0x50/0x70 xfs_corruption_error+0x134/0x150 xfs_free_ag_extent+0x7d3/0x1130 __xfs_free_extent+0x201/0x3c0 xfs_trans_free_extent+0x29b/0xa10 xfs_extent_free_finish_item+0x2a/0xb0 xfs_defer_finish_noroll+0x8d1/0x1b40 xfs_defer_finish+0x21/0x200 xfs_itruncate_extents_flags+0x1cb/0x650 xfs_free_eofblocks+0x18f/0x250 xfs_inactive+0x485/0x570 xfs_inodegc_worker+0x207/0x530 process_scheduled_works+0x24a/0xe10 worker_thread+0x5ac/0xc60 kthread+0x2cd/0x3c0 ret_from_fork+0x4a/0x80 ret_from_fork_asm+0x11/0x20 </TASK> XFS (dm-0): Corruption detected. Unmount and run xfs_repair After analyzing the disk image, it was found that the corruption was triggered by the fact that extent was recorded in both inode datafork and AGF btree blocks. After a long time of reproduction and analysis, we found that the reason of free sapce btree corruption was that the AGF btree was not recovered correctly. Consider the following situation, Checkpoint A and Checkpoint B are in the same record and share the same start LSN1, buf items of same object (AGF btree block) is included in both Checkpoint A and Checkpoint B. If the buf item in Checkpoint A has been recovered and updates metadata LSN permanently, then the buf item in Checkpoint B cannot be recovered, because log recovery skips items with a metadata LSN >= the current LSN of the recovery item. If there is still an inode item in Checkpoint B that records the Extent X, the Extent X will be recorded in both inode datafork and AGF btree block after Checkpoint B is recovered. Such transaction can be seen when allocing enxtent for inode bmap, it record both the addition of extent to the inode extent list and the removing extent from the AGF. |------------Record (LSN1)------------------|---Record (LSN2)---| |-------Checkpoint A----------|----------Checkpoint B-----------| | Buf Item(Extent X) | Buf Item / Inode item(Extent X) | | Extent X is freed | Extent X is allocated | After commit 12818d24db8a ("xfs: rework log recovery to submit buffers on LSN boundaries") was introduced, we submit buffers on lsn boundaries during log recovery. The above problem can be avoided under normal paths, but it's not guaranteed under abnormal paths. Consider the following process, if an error was encountered after recover buf item in Checkpoint A and before recover buf item in Checkpoint B, buffers that have been added to the buffer_list will still be submitted, this violates the submits rule on lsn boundaries. So buf item in Checkpoint B cannot be recovered on the next mount due to current lsn of transaction equal to metadata lsn on disk. The detailed process of the problem is as follows. First Mount: xlog_do_recovery_pass error = xlog_recover_process xlog_recover_process_data xlog_recover_process_ophdr xlog_recovery_process_trans ... /* recover buf item in Checkpoint A */ xlog_recover_buf_commit_pass2 xlog_recover_do_reg_buffer /* add buffer of agf btree block to buffer_list */ xfs_buf_delwri_queue(bp, buffer_list) ... ==> Encounter read IO error and return /* submit buffers regardless of error */ if (!list_empty(&buffer_list)) xfs_buf_delwri_submit(&buffer_list); <buf items of agf btree block in Checkpoint A recovery success> Second Mount: xlog_do_recovery_pass error = xlog_recover_process xlog_recover_process_data xlog_recover_process_ophdr xlog_recovery_process_trans ... /* recover buf item in Checkpoint B */ xlog_recover_buf_commit_pass2 /* buffer of agf btree block wouldn't added to buffer_list due to lsn equal to current_lsn */ if (XFS_LSN_CMP(lsn, current_lsn) >= 0) goto out_release <buf items of agf btree block in Checkpoint B wouldn't recovery> In order to make sure that submits buffers on lsn boundaries in the abnormal paths, we need to check error status before submit buffers that have been added from the last record processed. If error status exist, buffers in the bufffer_list should not be writen to disk. Canceling the buffers in the buffer_list directly isn't correct, unlike any other place where write list was canceled, these buffers has been initialized by xfs_buf_item_init() during recovery and held by buf item, buf items will not be released in xfs_buf_delwri_cancel(), it's not easy to solve. If the filesystem has been shut down, then delwri list submission will error out all buffers on the list via IO submission/completion and do all the correct cleanup automatically. So shutting down the filesystem could prevents buffers in the bufffer_list from being written to disk. Fixes: 50d5c8d8e938 ("xfs: check LSN ordering for v5 superblocks during recovery") Signed-off-by: Long Li <leo.lilong@huawei.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-17xfs: remove duplicate ifdefsShrikanth Hegde1-4/+0
when a ifdef is used in the below manner, second one could be considered as duplicate. ifdef DEFINE_A ...code block... ifdef DEFINE_A ...code block... endif ...code block... endif In the xfs code two such patterns were seen. Hence removing these ifdefs. No functional change is intended here. It only aims to improve code readability. Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-17xfs: disable sparse inode chunk alignment check when there is no alignmentDarrick J. Wong1-1/+1
While testing a 64k-blocksize filesystem, I noticed that xfs/709 fails to rebuild the inode btree with a bunch of "Corruption remains" messages. It turns out that when the inode chunk size is smaller than a single filesystem block, no block alignments constraints are necessary for inode chunk allocations, and sb_spino_align is zero. Hence we can skip the check. Fixes: dbfbf3bdf639 ("xfs: repair inode btrees") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13xfs: use xfs_defer_alloc a bit moreDave Chinner1-10/+5
Noticed by inspection, simple factoring allows the same allocation routine to be used for both transaction and recovery contexts. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13xfs: clean up remaining GFP_NOFS usersDave Chinner3-4/+4
These few remaining GFP_NOFS callers do not need to use GFP_NOFS at all. They are only called from a non-transactional context or cannot be accessed from memory reclaim due to other constraints. Hence they can just use GFP_KERNEL. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13xfs: place the CIL under nofs allocation contextDave Chinner1-1/+12
This is core code that needs to run in low memory conditions and can be triggered from memory reclaim. While it runs in a workqueue, it really shouldn't be recursing back into the filesystem during any memory allocation it needs to function. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13xfs: place intent recovery under NOFS allocation contextDave Chinner5-8/+19
When recovery starts processing intents, all of the initial intent allocations are done outside of transaction contexts. That means they need to specifically use GFP_NOFS as we do not want memory reclaim to attempt to run direct reclaim of filesystem objects while we have lots of objects added into deferred operations. Rather than use GFP_NOFS for these specific allocations, just place the entire intent recovery process under NOFS context and we can then just use GFP_KERNEL for these allocations. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13xfs: use GFP_KERNEL in pure transaction contextsDave Chinner12-31/+39
When running in a transaction context, memory allocations are scoped to GFP_NOFS. Hence we don't need to use GFP_NOFS contexts in pure transaction context allocations - GFP_KERNEL will automatically get converted to GFP_NOFS as appropriate. Go through the code and convert all the obvious GFP_NOFS allocations in transaction context to use GFP_KERNEL. This further reduces the explicit use of GFP_NOFS in XFS. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13xfs: use __GFP_NOLOCKDEP instead of GFP_NOFSDave Chinner8-33/+36
In the past we've had problems with lockdep false positives stemming from inode locking occurring in memory reclaim contexts (e.g. from superblock shrinkers). Lockdep doesn't know that inodes access from above memory reclaim cannot be accessed from below memory reclaim (and vice versa) but there has never been a good solution to solving this problem with lockdep annotations. This situation isn't unique to inode locks - buffers are also locked above and below memory reclaim, and we have to maintain lock ordering for them - and against inodes - appropriately. IOWs, the same code paths and locks are taken both above and below memory reclaim and so we always need to make sure the lock orders are consistent. We are spared the lockdep problems this might cause by the fact that semaphores and bit locks aren't covered by lockdep. In general, this sort of lockdep false positive detection is cause by code that runs GFP_KERNEL memory allocation with an actively referenced inode locked. When it is run from a transaction, memory allocation is automatically GFP_NOFS, so we don't have reclaim recursion issues. So in the places where we do memory allocation with inodes locked outside of a transaction, we have explicitly set them to use GFP_NOFS allocations to prevent lockdep false positives from being reported if the allocation dips into direct memory reclaim. More recently, __GFP_NOLOCKDEP was added to the memory allocation flags to tell lockdep not to track that particular allocation for the purposes of reclaim recursion detection. This is a much better way of preventing false positives - it allows us to use GFP_KERNEL context outside of transactions, and allows direct memory reclaim to proceed normally without throwing out false positive deadlock warnings. The obvious places that lock inodes and do memory allocation are the lookup paths and inode extent list initialisation. These occur in non-transactional GFP_KERNEL contexts, and so can run direct reclaim and lock inodes. This patch makes a first path through all the explicit GFP_NOFS allocations in XFS and converts the obvious ones to GFP_KERNEL | __GFP_NOLOCKDEP as a first step towards removing explicit GFP_NOFS allocations from the XFS code. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13xfs: use an empty transaction for fstrimDave Chinner1-4/+11
We currently use a btree walk in the fstrim code. This requires a btree cursor and btree cursors are only used inside transactions except for the fstrim code. This means that all the btree operations that allocate memory operate in both GFP_KERNEL and GFP_NOFS contexts. This causes problems with lockdep being unable to determine the difference between objects that are safe to lock both above and below memory reclaim. Free space btree buffers are definitely locked both above and below reclaim and that means we have to mark all btree infrastructure allocations with GFP_NOFS to avoid potential lockdep false positives. If we wrap this btree walk in an empty cursor, all btree walks are now done under transaction context and so all allocations inherit GFP_NOFS context from the tranaction. This enables us to move all the btree allocations to GFP_KERNEL context and hence help remove the explicit use of GFP_NOFS in XFS. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13xfs: convert remaining kmem_free() to kfree()Dave Chinner41-125/+101
The remaining callers of kmem_free() are freeing heap memory, so we can convert them directly to kfree() and get rid of kmem_free() altogether. This conversion was done with: $ for f in `git grep -l kmem_free fs/xfs`; do > sed -i s/kmem_free/kfree/ $f > done $ Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13xfs: convert kmem_free() for kvmalloc users to kvfree()Dave Chinner15-44/+44
Start getting rid of kmem_free() by converting all the cases where memory can come from vmalloc interfaces to calling kvfree() directly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13xfs: move kmem_to_page()Dave Chinner2-11/+11
Move it to the general xfs linux wrapper header file so we can prepare to remove kmem.h Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13xfs: convert kmem_alloc() to kmalloc()Dave Chinner21-131/+36
kmem_alloc() is just a thin wrapper around kmalloc() these days. Convert everything to use kmalloc() so we can get rid of the wrapper. Note: the transaction region allocation in xlog_add_to_transaction() can be a high order allocation. Converting it to use kmalloc(__GFP_NOFAIL) results in warnings in the page allocation code being triggered because the mm subsystem does not want us to use __GFP_NOFAIL with high order allocations like we've been doing with the kmem_alloc() wrapper for a couple of decades. Hence this specific case gets converted to xlog_kvmalloc() rather than kmalloc() to avoid this issue. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13xfs: convert kmem_zalloc() to kzalloc()Dave Chinner23-58/+64
There's no reason to keep the kmem_zalloc() around anymore, it's just a thin wrapper around kmalloc(), so lets get rid of it. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-10Merge tag 'mm-hotfixes-stable-2024-02-10-11-16' of ↵Linus Torvalds5-39/+69
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "21 hotfixes. 12 are cc:stable and the remainder pertain to post-6.7 issues or aren't considered to be needed in earlier kernel versions" * tag 'mm-hotfixes-stable-2024-02-10-11-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (21 commits) nilfs2: fix potential bug in end_buffer_async_write mm/damon/sysfs-schemes: fix wrong DAMOS tried regions update timeout setup nilfs2: fix hang in nilfs_lookup_dirty_data_buffers() MAINTAINERS: Leo Yan has moved mm/zswap: don't return LRU_SKIP if we have dropped lru lock fs,hugetlb: fix NULL pointer dereference in hugetlbs_fill_super mailmap: switch email address for John Moon mm: zswap: fix objcg use-after-free in entry destruction mm/madvise: don't forget to leave lazy MMU mode in madvise_cold_or_pageout_pte_range() arch/arm/mm: fix major fault accounting when retrying under per-VMA lock selftests: core: include linux/close_range.h for CLOSE_RANGE_* macros mm/memory-failure: fix crash in split_huge_page_to_list from soft_offline_page mm: memcg: optimize parent iteration in memcg_rstat_updated() nilfs2: fix data corruption in dsync block recovery for small block sizes mm/userfaultfd: UFFDIO_MOVE implementation should use ptep_get() exit: wait_task_zombie: kill the no longer necessary spin_lock_irq(siglock) fs/proc: do_task_stat: use sig->stats_lock to gather the threads/children stats fs/proc: do_task_stat: move thread_group_cputime_adjusted() outside of lock_task_sighand() getrusage: use sig->stats_lock rather than lock_task_sighand() getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand() ...
2024-02-10Merge tag '6.8-rc3-ksmbd-server-fixes' of git://git.samba.org/ksmbdLinus Torvalds2-2/+7
Pull smb server fixes from Steve French: "Two ksmbd server fixes: - memory leak fix - a minor kernel-doc fix" * tag '6.8-rc3-ksmbd-server-fixes' of git://git.samba.org/ksmbd: ksmbd: free aux buffer if ksmbd_iov_pin_rsp_read fails ksmbd: Add kernel-doc for ksmbd_extract_sharename() function
2024-02-09Merge tag '6.8-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds7-11/+36
Pull smb client fixes from Steve French: - reconnect fix - multichannel channel selection fix - minor mount warning fix - reparse point fix - null pointer check improvement * tag '6.8-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6: smb3: clarify mount warning cifs: handle cases where multiple sessions share connection cifs: change tcon status when need_reconnect is set on it smb: client: set correct d_type for reparse points under DFS mounts smb3: add missing null server pointer check
2024-02-09Merge tag 'ceph-for-6.8-rc4' of https://github.com/ceph/ceph-clientLinus Torvalds5-15/+9
Pull ceph fixes from Ilya Dryomov: "Some fscrypt-related fixups (sparse reads are used only for encrypted files) and two cap handling fixes from Xiubo and Rishabh" * tag 'ceph-for-6.8-rc4' of https://github.com/ceph/ceph-client: ceph: always check dir caps asynchronously ceph: prevent use-after-free in encode_cap_msg() ceph: always set initial i_blkbits to CEPH_FSCRYPT_BLOCK_SHIFT libceph: just wait for more data to be available on the socket libceph: rename read_sparse_msg_*() to read_partial_sparse_msg_*() libceph: fail sparse-read if the data length doesn't match
2024-02-09Merge tag 'ntfs3_for_6.8' of ↵Linus Torvalds16-247/+381
https://github.com/Paragon-Software-Group/linux-ntfs3 Pull ntfs3 fixes from Konstantin Komarov: "Fixed: - size update for compressed file - some logic errors, overflows - memory leak - some code was refactored Added: - implement super_operations::shutdown Improved: - alternative boot processing - reduced stack usage" * tag 'ntfs3_for_6.8' of https://github.com/Paragon-Software-Group/linux-ntfs3: (28 commits) fs/ntfs3: Slightly simplify ntfs_inode_printk() fs/ntfs3: Add ioctl operation for directories (FITRIM) fs/ntfs3: Fix oob in ntfs_listxattr fs/ntfs3: Fix an NULL dereference bug fs/ntfs3: Update inode->i_size after success write into compressed file fs/ntfs3: Fixed overflow check in mi_enum_attr() fs/ntfs3: Correct function is_rst_area_valid fs/ntfs3: Use i_size_read and i_size_write fs/ntfs3: Prevent generic message "attempt to access beyond end of device" fs/ntfs3: use non-movable memory for ntfs3 MFT buffer cache fs/ntfs3: Use kvfree to free memory allocated by kvmalloc fs/ntfs3: Disable ATTR_LIST_ENTRY size check fs/ntfs3: Fix c/mtime typo fs/ntfs3: Add NULL ptr dereference checking at the end of attr_allocate_frame() fs/ntfs3: Add and fix comments fs/ntfs3: ntfs3_forced_shutdown use int instead of bool fs/ntfs3: Implement super_operations::shutdown fs/ntfs3: Drop suid and sgid bits as a part of fpunch fs/ntfs3: Add file_modified fs/ntfs3: Correct use bh_read ...
2024-02-09smb3: clarify mount warningSteve French1-1/+1
When a user tries to use the "sec=krb5p" mount parameter to encrypt data on connection to a server (when authenticating with Kerberos), we indicate that it is not supported, but do not note the equivalent recommended mount parameter ("sec=krb5,seal") which turns on encryption for that mount (and uses Kerberos for auth). Update the warning message. Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-02-09cifs: handle cases where multiple sessions share connectionShyam Prasad N2-1/+6
Based on our implementation of multichannel, it is entirely possible that a server struct may not be found in any channel of an SMB session. In such cases, we should be prepared to move on and search for the server struct in the next session. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-02-09cifs: change tcon status when need_reconnect is set on itShyam Prasad N3-1/+14
When a tcon is marked for need_reconnect, the intention is to have it reconnected. This change adjusts tcon->status in cifs_tree_connect when need_reconnect is set. Also, this change has a minor correction in resetting need_reconnect on success. It makes sure that it is done with tc_lock held. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-02-08smb: client: set correct d_type for reparse points under DFS mountsPaulo Alcantara2-7/+14
Send query dir requests with an info level of SMB_FIND_FILE_FULL_DIRECTORY_INFO rather than SMB_FIND_FILE_DIRECTORY_INFO when the client is generating its own inode numbers (e.g. noserverino) so that reparse tags still can be parsed directly from the responses, but server won't send UniqueId (server inode number) Signed-off-by: Paulo Alcantara <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-02-08smb3: add missing null server pointer checkSteve French1-1/+1
Address static checker warning in cifs_ses_get_chan_index(): warn: variable dereferenced before check 'server' To be consistent, and reduce risk, we should add another check for null server pointer. Fixes: 88675b22d34e ("cifs: do not search for channel if server is terminating") Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-02-07nilfs2: fix potential bug in end_buffer_async_writeRyusuke Konishi1-3/+5
According to a syzbot report, end_buffer_async_write(), which handles the completion of block device writes, may detect abnormal condition of the buffer async_write flag and cause a BUG_ON failure when using nilfs2. Nilfs2 itself does not use end_buffer_async_write(). But, the async_write flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") as a means of resolving double list insertion of dirty blocks in nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the resulting crash. This modification is safe as long as it is used for file data and b-tree node blocks where the page caches are independent. However, it was irrelevant and redundant to also introduce async_write for segment summary and super root blocks that share buffers with the backing device. This led to the possibility that the BUG_ON check in end_buffer_async_write would fail as described above, if independent writebacks of the backing device occurred in parallel. The use of async_write for segment summary buffers has already been removed in a previous change. Fix this issue by removing the manipulation of the async_write flag for the remaining super root block buffer. Link: https://lkml.kernel.org/r/20240203161645.4992-1-konishi.ryusuke@gmail.com Fixes: 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+5c04210f7c7f897c1e7f@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000019a97c05fd42f8c8@google.com Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07nilfs2: fix hang in nilfs_lookup_dirty_data_buffers()Ryusuke Konishi1-1/+7
Syzbot reported a hang issue in migrate_pages_batch() called by mbind() and nilfs_lookup_dirty_data_buffers() called in the log writer of nilfs2. While migrate_pages_batch() locks a folio and waits for the writeback to complete, the log writer thread that should bring the writeback to completion picks up the folio being written back in nilfs_lookup_dirty_data_buffers() that it calls for subsequent log creation and was trying to lock the folio. Thus causing a deadlock. In the first place, it is unexpected that folios/pages in the middle of writeback will be updated and become dirty. Nilfs2 adds a checksum to verify the validity of the log being written and uses it for recovery at mount, so data changes during writeback are suppressed. Since this is broken, an unclean shutdown could potentially cause recovery to fail. Investigation revealed that the root cause is that the wait for writeback completion in nilfs_page_mkwrite() is conditional, and if the backing device does not require stable writes, data may be modified without waiting. Fix these issues by making nilfs_page_mkwrite() wait for writeback to finish regardless of the stable write requirement of the backing device. Link: https://lkml.kernel.org/r/20240131145657.4209-1-konishi.ryusuke@gmail.com Fixes: 1d1d1a767206 ("mm: only enforce stable page writes if the backing device requires it") Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+ee2ae68da3b22d04cd8d@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000047d819061004ad6c@google.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07fs,hugetlb: fix NULL pointer dereference in hugetlbs_fill_superOscar Salvador1-2/+4
When configuring a hugetlb filesystem via the fsconfig() syscall, there is a possible NULL dereference in hugetlbfs_fill_super() caused by assigning NULL to ctx->hstate in hugetlbfs_parse_param() when the requested pagesize is non valid. E.g: Taking the following steps: fd = fsopen("hugetlbfs", FSOPEN_CLOEXEC); fsconfig(fd, FSCONFIG_SET_STRING, "pagesize", "1024", 0); fsconfig(fd, FSCONFIG_CMD_CREATE, NULL, NULL, 0); Given that the requested "pagesize" is invalid, ctxt->hstate will be replaced with NULL, losing its previous value, and we will print an error: ... ... case Opt_pagesize: ps = memparse(param->string, &rest); ctx->hstate = h; if (!ctx->hstate) { pr_err("Unsupported page size %lu MB\n", ps / SZ_1M); return -EINVAL; } return 0; ... ... This is a problem because later on, we will dereference ctxt->hstate in hugetlbfs_fill_super() ... ... sb->s_blocksize = huge_page_size(ctx->hstate); ... ... Causing below Oops. Fix this by replacing cxt->hstate value only when then pagesize is known to be valid. kernel: hugetlbfs: Unsupported page size 0 MB kernel: BUG: kernel NULL pointer dereference, address: 0000000000000028 kernel: #PF: supervisor read access in kernel mode kernel: #PF: error_code(0x0000) - not-present page kernel: PGD 800000010f66c067 P4D 800000010f66c067 PUD 1b22f8067 PMD 0 kernel: Oops: 0000 [#1] PREEMPT SMP PTI kernel: CPU: 4 PID: 5659 Comm: syscall Tainted: G E 6.8.0-rc2-default+ #22 5a47c3fef76212addcc6eb71344aabc35190ae8f kernel: Hardware name: Intel Corp. GROVEPORT/GROVEPORT, BIOS GVPRCRB1.86B.0016.D04.1705030402 05/03/2017 kernel: RIP: 0010:hugetlbfs_fill_super+0xb4/0x1a0 kernel: Code: 48 8b 3b e8 3e c6 ed ff 48 85 c0 48 89 45 20 0f 84 d6 00 00 00 48 b8 ff ff ff ff ff ff ff 7f 4c 89 e7 49 89 44 24 20 48 8b 03 <8b> 48 28 b8 00 10 00 00 48 d3 e0 49 89 44 24 18 48 8b 03 8b 40 28 kernel: RSP: 0018:ffffbe9960fcbd48 EFLAGS: 00010246 kernel: RAX: 0000000000000000 RBX: ffff9af5272ae780 RCX: 0000000000372004 kernel: RDX: ffffffffffffffff RSI: ffffffffffffffff RDI: ffff9af555e9b000 kernel: RBP: ffff9af52ee66b00 R08: 0000000000000040 R09: 0000000000370004 kernel: R10: ffffbe9960fcbd48 R11: 0000000000000040 R12: ffff9af555e9b000 kernel: R13: ffffffffa66b86c0 R14: ffff9af507d2f400 R15: ffff9af507d2f400 kernel: FS: 00007ffbc0ba4740(0000) GS:ffff9b0bd7000000(0000) knlGS:0000000000000000 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kernel: CR2: 0000000000000028 CR3: 00000001b1ee0000 CR4: 00000000001506f0 kernel: Call Trace: kernel: <TASK> kernel: ? __die_body+0x1a/0x60 kernel: ? page_fault_oops+0x16f/0x4a0 kernel: ? search_bpf_extables+0x65/0x70 kernel: ? fixup_exception+0x22/0x310 kernel: ? exc_page_fault+0x69/0x150 kernel: ? asm_exc_page_fault+0x22/0x30 kernel: ? __pfx_hugetlbfs_fill_super+0x10/0x10 kernel: ? hugetlbfs_fill_super+0xb4/0x1a0 kernel: ? hugetlbfs_fill_super+0x28/0x1a0 kernel: ? __pfx_hugetlbfs_fill_super+0x10/0x10 kernel: vfs_get_super+0x40/0xa0 kernel: ? __pfx_bpf_lsm_capable+0x10/0x10 kernel: vfs_get_tree+0x25/0xd0 kernel: vfs_cmd_create+0x64/0xe0 kernel: __x64_sys_fsconfig+0x395/0x410 kernel: do_syscall_64+0x80/0x160 kernel: ? syscall_exit_to_user_mode+0x82/0x240 kernel: ? do_syscall_64+0x8d/0x160 kernel: ? syscall_exit_to_user_mode+0x82/0x240 kernel: ? do_syscall_64+0x8d/0x160 kernel: ? exc_page_fault+0x69/0x150 kernel: entry_SYSCALL_64_after_hwframe+0x6e/0x76 kernel: RIP: 0033:0x7ffbc0cb87c9 kernel: Code: 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 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 73 01 c3 48 8b 0d 97 96 0d 00 f7 d8 64 89 01 48 kernel: RSP: 002b:00007ffc29d2f388 EFLAGS: 00000206 ORIG_RAX: 00000000000001af kernel: RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ffbc0cb87c9 kernel: RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003 kernel: RBP: 00007ffc29d2f3b0 R08: 0000000000000000 R09: 0000000000000000 kernel: R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 kernel: R13: 00007ffc29d2f4c0 R14: 0000000000000000 R15: 0000000000000000 kernel: </TASK> kernel: Modules linked in: rpcsec_gss_krb5(E) auth_rpcgss(E) nfsv4(E) dns_resolver(E) nfs(E) lockd(E) grace(E) sunrpc(E) netfs(E) af_packet(E) bridge(E) stp(E) llc(E) iscsi_ibft(E) iscsi_boot_sysfs(E) intel_rapl_msr(E) intel_rapl_common(E) iTCO_wdt(E) intel_pmc_bxt(E) sb_edac(E) iTCO_vendor_support(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) coretemp(E) kvm_intel(E) rfkill(E) ipmi_ssif(E) kvm(E) acpi_ipmi(E) irqbypass(E) pcspkr(E) igb(E) ipmi_si(E) mei_me(E) i2c_i801(E) joydev(E) intel_pch_thermal(E) i2c_smbus(E) dca(E) lpc_ich(E) mei(E) ipmi_devintf(E) ipmi_msghandler(E) acpi_pad(E) tiny_power_button(E) button(E) fuse(E) efi_pstore(E) configfs(E) ip_tables(E) x_tables(E) ext4(E) mbcache(E) jbd2(E) hid_generic(E) usbhid(E) sd_mod(E) t10_pi(E) crct10dif_pclmul(E) crc32_pclmul(E) crc32c_intel(E) polyval_clmulni(E) ahci(E) xhci_pci(E) polyval_generic(E) gf128mul(E) ghash_clmulni_intel(E) sha512_ssse3(E) sha256_ssse3(E) xhci_pci_renesas(E) libahci(E) ehci_pci(E) sha1_ssse3(E) xhci_hcd(E) ehci_hcd(E) libata(E) kernel: mgag200(E) i2c_algo_bit(E) usbcore(E) wmi(E) sg(E) dm_multipath(E) dm_mod(E) scsi_dh_rdac(E) scsi_dh_emc(E) scsi_dh_alua(E) scsi_mod(E) scsi_common(E) aesni_intel(E) crypto_simd(E) cryptd(E) kernel: Unloaded tainted modules: acpi_cpufreq(E):1 fjes(E):1 kernel: CR2: 0000000000000028 kernel: ---[ end trace 0000000000000000 ]--- kernel: RIP: 0010:hugetlbfs_fill_super+0xb4/0x1a0 kernel: Code: 48 8b 3b e8 3e c6 ed ff 48 85 c0 48 89 45 20 0f 84 d6 00 00 00 48 b8 ff ff ff ff ff ff ff 7f 4c 89 e7 49 89 44 24 20 48 8b 03 <8b> 48 28 b8 00 10 00 00 48 d3 e0 49 89 44 24 18 48 8b 03 8b 40 28 kernel: RSP: 0018:ffffbe9960fcbd48 EFLAGS: 00010246 kernel: RAX: 0000000000000000 RBX: ffff9af5272ae780 RCX: 0000000000372004 kernel: RDX: ffffffffffffffff RSI: ffffffffffffffff RDI: ffff9af555e9b000 kernel: RBP: ffff9af52ee66b00 R08: 0000000000000040 R09: 0000000000370004 kernel: R10: ffffbe9960fcbd48 R11: 0000000000000040 R12: ffff9af555e9b000 kernel: R13: ffffffffa66b86c0 R14: ffff9af507d2f400 R15: ffff9af507d2f400 kernel: FS: 00007ffbc0ba4740(0000) GS:ffff9b0bd7000000(0000) knlGS:0000000000000000 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kernel: CR2: 0000000000000028 CR3: 00000001b1ee0000 CR4: 00000000001506f0 Link: https://lkml.kernel.org/r/20240130210418.3771-1-osalvador@suse.de Fixes: 32021982a324 ("hugetlbfs: Convert to fs_context") Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Oscar Salvador <osalvador@suse.de> Acked-by: Muchun Song <muchun.song@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07nilfs2: fix data corruption in dsync block recovery for small block sizesRyusuke Konishi1-3/+4
The helper function nilfs_recovery_copy_block() of nilfs_recovery_dsync_blocks(), which recovers data from logs created by data sync writes during a mount after an unclean shutdown, incorrectly calculates the on-page offset when copying repair data to the file's page cache. In environments where the block size is smaller than the page size, this flaw can cause data corruption and leak uninitialized memory bytes during the recovery process. Fix these issues by correcting this byte offset calculation on the page. Link: https://lkml.kernel.org/r/20240124121936.10575-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07fs/proc: do_task_stat: use sig->stats_lock to gather the threads/children statsOleg Nesterov1-26/+32
lock_task_sighand() can trigger a hard lockup. If NR_CPUS threads call do_task_stat() at the same time and the process has NR_THREADS, it will spin with irqs disabled O(NR_CPUS * NR_THREADS) time. Change do_task_stat() to use sig->stats_lock to gather the statistics outside of ->siglock protected section, in the likely case this code will run lockless. Link: https://lkml.kernel.org/r/20240123153357.GA21857@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Dylan Hatch <dylanbhatch@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07fs/proc: do_task_stat: move thread_group_cputime_adjusted() outside of ↵Oleg Nesterov1-4/+6
lock_task_sighand() Patch series "fs/proc: do_task_stat: use sig->stats_". do_task_stat() has the same problem as getrusage() had before "getrusage: use sig->stats_lock rather than lock_task_sighand()": a hard lockup. If NR_CPUS threads call lock_task_sighand() at the same time and the process has NR_THREADS, spin_lock_irq will spin with irqs disabled O(NR_CPUS * NR_THREADS) time. This patch (of 3): thread_group_cputime() does its own locking, we can safely shift thread_group_cputime_adjusted() which does another for_each_thread loop outside of ->siglock protected section. Not only this removes for_each_thread() from the critical section with irqs disabled, this removes another case when stats_lock is taken with siglock held. We want to remove this dependency, then we can change the users of stats_lock to not disable irqs. Link: https://lkml.kernel.org/r/20240123153313.GA21832@redhat.com Link: https://lkml.kernel.org/r/20240123153355.GA21854@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Dylan Hatch <dylanbhatch@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07mm: hugetlb pages should not be reserved by shmat() if SHM_NORESERVEPrakash Sangappa1-1/+12
For shared memory of type SHM_HUGETLB, hugetlb pages are reserved in shmget() call. If SHM_NORESERVE flags is specified then the hugetlb pages are not reserved. However when the shared memory is attached with the shmat() call the hugetlb pages are getting reserved incorrectly for SHM_HUGETLB shared memory created with SHM_NORESERVE which is a bug. ------------------------------- Following test shows the issue. $cat shmhtb.c int main() { int shmflags = 0660 | IPC_CREAT | SHM_HUGETLB | SHM_NORESERVE; int shmid; shmid = shmget(SKEY, SHMSZ, shmflags); if (shmid < 0) { printf("shmat: shmget() failed, %d\n", errno); return 1; } printf("After shmget()\n"); system("cat /proc/meminfo | grep -i hugepages_"); shmat(shmid, NULL, 0); printf("\nAfter shmat()\n"); system("cat /proc/meminfo | grep -i hugepages_"); shmctl(shmid, IPC_RMID, NULL); return 0; } #sysctl -w vm.nr_hugepages=20 #./shmhtb After shmget() HugePages_Total: 20 HugePages_Free: 20 HugePages_Rsvd: 0 HugePages_Surp: 0 After shmat() HugePages_Total: 20 HugePages_Free: 20 HugePages_Rsvd: 5 <-- HugePages_Surp: 0 -------------------------------- Fix is to ensure that hugetlb pages are not reserved for SHM_HUGETLB shared memory in the shmat() call. Link: https://lkml.kernel.org/r/1706040282-12388-1-git-send-email-prakash.sangappa@oracle.com Signed-off-by: Prakash Sangappa <prakash.sangappa@oracle.com> Acked-by: Muchun Song <muchun.song@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>