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5 daysMerge tag 'vfs-6.17-rc1.mmap_prepare' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull mmap_prepare updates from Christian Brauner: "Last cycle we introduce f_op->mmap_prepare() in c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file callback"). This is preferred to the existing f_op->mmap() hook as it does require a VMA to be established yet, thus allowing the mmap logic to invoke this hook far, far earlier, prior to inserting a VMA into the virtual address space, or performing any other heavy handed operations. This allows for much simpler unwinding on error, and for there to be a single attempt at merging a VMA rather than having to possibly reattempt a merge based on potentially altered VMA state. Far more importantly, it prevents inappropriate manipulation of incompletely initialised VMA state, which is something that has been the cause of bugs and complexity in the past. The intent is to gradually deprecate f_op->mmap, and in that vein this series coverts the majority of file systems to using f_op->mmap_prepare. Prerequisite steps are taken - firstly ensuring all checks for mmap capabilities use the file_has_valid_mmap_hooks() helper rather than directly checking for f_op->mmap (which is now not a valid check) and secondly updating daxdev_mapping_supported() to not require a VMA parameter to allow ext4 and xfs to be converted. Commit bb666b7c2707 ("mm: add mmap_prepare() compatibility layer for nested file systems") handles the nasty edge-case of nested file systems like overlayfs, which introduces a compatibility shim to allow f_op->mmap_prepare() to be invoked from an f_op->mmap() callback. This allows for nested filesystems to continue to function correctly with all file systems regardless of which callback is used. Once we finally convert all file systems, this shim can be removed. As a result, ecryptfs, fuse, and overlayfs remain unaltered so they can nest all other file systems. We additionally do not update resctl - as this requires an update to remap_pfn_range() (or an alternative to it) which we defer to a later series, equally we do not update cramfs which needs a mixed mapping insertion with the same issue, nor do we update procfs, hugetlbfs, syfs or kernfs all of which require VMAs for internal state and hooks. We shall return to all of these later" * tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: doc: update porting, vfs documentation to describe mmap_prepare() fs: replace mmap hook with .mmap_prepare for simple mappings fs: convert most other generic_file_*mmap() users to .mmap_prepare() fs: convert simple use of generic_file_*_mmap() to .mmap_prepare() mm/filemap: introduce generic_file_*_mmap_prepare() helpers fs/xfs: transition from deprecated .mmap hook to .mmap_prepare fs/ext4: transition from deprecated .mmap hook to .mmap_prepare fs/dax: make it possible to check dev dax support without a VMA fs: consistently use can_mmap_file() helper mm/nommu: use file_has_valid_mmap_hooks() helper mm: rename call_mmap/mmap_prepare to vfs_mmap/mmap_prepare
5 daysMerge tag 'vfs-6.17-rc1.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc VFS updates from Christian Brauner: "This contains the usual selections of misc updates for this cycle. Features: - Add ext4 IOCB_DONTCACHE support This refactors the address_space_operations write_begin() and write_end() callbacks to take const struct kiocb * as their first argument, allowing IOCB flags such as IOCB_DONTCACHE to propagate to the filesystem's buffered I/O path. Ext4 is updated to implement handling of the IOCB_DONTCACHE flag and advertises support via the FOP_DONTCACHE file operation flag. Additionally, the i915 driver's shmem write paths are updated to bypass the legacy write_begin/write_end interface in favor of directly calling write_iter() with a constructed synchronous kiocb. Another i915 change replaces a manual write loop with kernel_write() during GEM shmem object creation. Cleanups: - don't duplicate vfs_open() in kernel_file_open() - proc_fd_getattr(): don't bother with S_ISDIR() check - fs/ecryptfs: replace snprintf with sysfs_emit in show function - vfs: Remove unnecessary list_for_each_entry_safe() from evict_inodes() - filelock: add new locks_wake_up_waiter() helper - fs: Remove three arguments from block_write_end() - VFS: change old_dir and new_dir in struct renamedata to dentrys - netfs: Remove unused declaration netfs_queue_write_request() Fixes: - eventpoll: Fix semi-unbounded recursion - eventpoll: fix sphinx documentation build warning - fs/read_write: Fix spelling typo - fs: annotate data race between poll_schedule_timeout() and pollwake() - fs/pipe: set FMODE_NOWAIT in create_pipe_files() - docs/vfs: update references to i_mutex to i_rwsem - fs/buffer: remove comment about hard sectorsize - fs/buffer: remove the min and max limit checks in __getblk_slow() - fs/libfs: don't assume blocksize <= PAGE_SIZE in generic_check_addressable - fs_context: fix parameter name in infofc() macro - fs: Prevent file descriptor table allocations exceeding INT_MAX" * tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (24 commits) netfs: Remove unused declaration netfs_queue_write_request() eventpoll: fix sphinx documentation build warning ext4: support uncached buffered I/O mm/pagemap: add write_begin_get_folio() helper function fs: change write_begin/write_end interface to take struct kiocb * drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter drm/i915: Use kernel_write() in shmem object create eventpoll: Fix semi-unbounded recursion vfs: Remove unnecessary list_for_each_entry_safe() from evict_inodes() fs/libfs: don't assume blocksize <= PAGE_SIZE in generic_check_addressable fs/buffer: remove the min and max limit checks in __getblk_slow() fs: Prevent file descriptor table allocations exceeding INT_MAX fs: Remove three arguments from block_write_end() fs/ecryptfs: replace snprintf with sysfs_emit in show function fs: annotate suspected data race between poll_schedule_timeout() and pollwake() docs/vfs: update references to i_mutex to i_rwsem fs/buffer: remove comment about hard sectorsize fs_context: fix parameter name in infofc() macro VFS: change old_dir and new_dir in struct renamedata to dentrys proc_fd_getattr(): don't bother with S_ISDIR() check ...
2025-07-16fs: change write_begin/write_end interface to take struct kiocb *Taotao Chen
Change the address_space_operations callbacks write_begin() and write_end() to take struct kiocb * as the first argument instead of struct file *. Update all affected function prototypes, implementations, call sites, and related documentation across VFS, filesystems, and block layer. Part of a series refactoring address_space_operations write_begin and write_end callbacks to use struct kiocb for passing write context and flags. Signed-off-by: Taotao Chen <chentaotao@didiglobal.com> Link: https://lore.kernel.org/20250716093559.217344-4-chentaotao@didiglobal.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-06-17fs: convert simple use of generic_file_*_mmap() to .mmap_prepare()Lorenzo Stoakes
Since commit c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file callback"), the f_op->mmap() hook has been deprecated in favour of f_op->mmap_prepare(). We have provided generic .mmap_prepare() equivalents, so update all file systems that specify these directly in their file_operations structures. This updates 9p, adfs, affs, bfs, fat, hfs, hfsplus, hostfs, hpfs, jffs2, jfs, minix, omfs, ramfs and ufs file systems directly. It updates generic_ro_fops which impacts qnx4, cramfs, befs, squashfs, frebxfs, qnx6, efs, romfs, erofs and isofs file systems. There are remaining file systems which use generic hooks in a less direct way which we address in a subsequent commit. Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Link: https://lore.kernel.org/c7dc90e44a9e75e750939ea369290d6e441a18e6.1750099179.git.lorenzo.stoakes@oracle.com Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-06-11devpts, sunrpc, hostfs: don't bother with ->d_opAl Viro
Default ->d_op being simple_dentry_operations is equivalent to leaving it NULL and putting DCACHE_DONTCACHE into ->s_d_flags. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-06-10new helper: set_default_d_op()Al Viro
... to be used instead of manually assigning to ->s_d_op. All in-tree filesystem converted (and field itself is renamed, so any out-of-tree ones in need of conversion will be caught by compiler). Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-04-02Merge tag 'uml-for-linux-6.15-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux Pull UML updates from Johannes Berg: - proper nofault accesses and read-only rodata - hostfs fix for host inode number reuse - fixes for host errno handling - various cleanups/small fixes * tag 'uml-for-linux-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: um: Rewrite the sigio workaround based on epoll and tgkill um: Prohibit the VM_CLONE flag in run_helper_thread() um: Switch to the pthread-based helper in sigio workaround um: ubd: Switch to the pthread-based helper um: Add pthread-based helper support um: x86: clean up elf specific definitions um: Store full CSGSFS and SS register from mcontext um: virt-pci: Refactor virtio_pcidev into its own module um: work around sched_yield not yielding in time-travel mode um/locking: Remove semicolon from "lock" prefix um: Update min_low_pfn to match changes in uml_reserved um: use str_yes_no() to remove hardcoded "yes" and "no" um: hostfs: avoid issues on inode number reuse by host um: Allocate vdso page pointer statically um: remove copy_from_kernel_nofault_allowed um: mark rodata read-only and implement _nofault accesses um: Pass the correct Rust target and options with gcc
2025-03-18um: hostfs: avoid issues on inode number reuse by hostBenjamin Berg
Some file systems (e.g. ext4) may reuse inode numbers once the inode is not in use anymore. Usually hostfs will keep an FD open for each inode, but this is not always the case. In the case of sockets, this cannot even be done properly. As such, the following sequence of events was possible: * application creates and deletes a socket * hostfs creates/deletes the socket on the host * inode is still in the hostfs cache * hostfs creates a new file * ext4 on the outside reuses the inode number * hostfs finds the socket inode for the newly created file * application receives -ENXIO when opening the file As mentioned, this can only happen if the deleted file is a special file that is never opened on the host (i.e. no .open fop). As such, to prevent issues, it is sufficient to check that the inode has the expected type. That said, also add a check for the inode birth time, just to be on the safe side. Fixes: 74ce793bcbde ("hostfs: Fix ephemeral inodes") Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Reviewed-by: Mickaël Salaün <mic@digikod.net> Tested-by: Mickaël Salaün <mic@digikod.net> Link: https://patch.msgid.link/20250214092822.1241575-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2025-02-27hostfs: store inode in dentry after mkdir if possible.NeilBrown
After handling a mkdir, get the inode for the name and use d_splice_alias() to store the correct dentry in the dcache. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: NeilBrown <neilb@suse.de> Link: https://lore.kernel.org/r/20250227013949.536172-3-neilb@suse.de Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-27Change inode_operations.mkdir to return struct dentry *NeilBrown
Some filesystems, such as NFS, cifs, ceph, and fuse, do not have complete control of sequencing on the actual filesystem (e.g. on a different server) and may find that the inode created for a mkdir request already exists in the icache and dcache by the time the mkdir request returns. For example, if the filesystem is mounted twice the directory could be visible on the other mount before it is on the original mount, and a pair of name_to_handle_at(), open_by_handle_at() calls could instantiate the directory inode with an IS_ROOT() dentry before the first mkdir returns. This means that the dentry passed to ->mkdir() may not be the one that is associated with the inode after the ->mkdir() completes. Some callers need to interact with the inode after the ->mkdir completes and they currently need to perform a lookup in the (rare) case that the dentry is no longer hashed. This lookup-after-mkdir requires that the directory remains locked to avoid races. Planned future patches to lock the dentry rather than the directory will mean that this lookup cannot be performed atomically with the mkdir. To remove this barrier, this patch changes ->mkdir to return the resulting dentry if it is different from the one passed in. Possible returns are: NULL - the directory was created and no other dentry was used ERR_PTR() - an error occurred non-NULL - this other dentry was spliced in This patch only changes file-systems to return "ERR_PTR(err)" instead of "err" or equivalent transformations. Subsequent patches will make further changes to some file-systems to return a correct dentry. Not all filesystems reliably result in a positive hashed dentry: - NFS, cifs, hostfs will sometimes need to perform a lookup of the name to get inode information. Races could result in this returning something different. Note that this lookup is non-atomic which is what we are trying to avoid. Placing the lookup in filesystem code means it only happens when the filesystem has no other option. - kernfs and tracefs leave the dentry negative and the ->revalidate operation ensures that lookup will be called to correctly populate the dentry. This could be fixed but I don't think it is important to any of the users of vfs_mkdir() which look at the dentry. The recommendation to use d_drop();d_splice_alias() is ugly but fits with current practice. A planned future patch will change this. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: NeilBrown <neilb@suse.de> Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-01-31Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds
Pull hostfs fix from Al Viro: "Fix hostfs __dentry_name() string handling. The use of strcpy() with overlapping source and destination is a UB; original loop hadn't been. More to the point, the whole thing is much easier done with memcpy() + memmove()" * tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: hostfs: fix string handling in __dentry_name()
2025-01-11hostfs: fix string handling in __dentry_name()Al Viro
strcpy() should not be used with destination potentially overlapping the source; what's more, strscpy() in there is pointless - we already know the amount we want to copy; might as well use memcpy(). Fixes: c278e81b8a02 "hostfs: Remove open coded strcpy()" Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-01-10hostfs: Convert to writepagesMatthew Wilcox (Oracle)
If we add a migrate_folio operation, we can convert the writepage operation to writepages. The large folio support here is illusory; we would need to kmap each page in turn for proper support. But we do remove a few hidden calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://patch.msgid.link/20241220051500.1919389-1-willy@infradead.org Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-11-15hostfs: Fix the NULL vs IS_ERR() bug for __filemap_get_folio()ZhangPeng
The __filemap_get_folio() function returns error pointers. It never returns NULL. So use IS_ERR() to check it. Fixes: 1da86618bdce ("fs: Convert aops->write_begin to take a folio") Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Acked-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at>
2024-10-23hostfs: Do not propagate hostfs parameter to kernelTiwei Bie
This parameter is UML specific and is unknown to kernel. It should not be propagated to kernel, otherwise it will be passed to user space as an environment option by kernel with a warning like: Unknown kernel command line parameters "hostfs=/foo", will be passed to user space. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241011040441.1586345-7-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-08-07fs: Convert aops->write_begin to take a folioMatthew Wilcox (Oracle)
Convert all callers from working on a page to working on one page of a folio (support for working on an entire folio can come later). Removes a lot of folio->page->folio conversions. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-07fs: Convert aops->write_end to take a folioMatthew Wilcox (Oracle)
Most callers have a folio, and most implementations operate on a folio, so remove the conversion from folio->page->folio to fit through this interface. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-07hostfs: Convert hostfs_write_end() to use a folioMatthew Wilcox (Oracle)
Convert the passed page to a folio and operate on that. Replaces four calls to compound_head() with one. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-07-27Merge tag 'vfs-6.11-rc1.fixes.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs fixes from Christian Brauner: "This contains two fixes for this merge window: VFS: - I noticed that it is possible for a privileged user to mount most filesystems with a non-initial user namespace in sb->s_user_ns. When fsopen() is called in a non-init namespace the caller's namespace is recorded in fs_context->user_ns. If the returned file descriptor is then passed to a process privileged in init_user_ns, that process can call fsconfig(fd_fs, FSCONFIG_CMD_CREATE*), creating a new superblock with sb->s_user_ns set to the namespace of the process which called fsopen(). This is problematic as only filesystems that raise FS_USERNS_MOUNT are known to be able to support a non-initial s_user_ns. Others may suffer security issues, on-disk corruption or outright crash the kernel. Prevent that by restricting such delegation to filesystems that allow FS_USERNS_MOUNT. Note, that this delegation requires a privileged process to actually create the superblock so either the privileged process is cooperaing or someone must have tricked a privileged process into operating on a fscontext file descriptor whose origin it doesn't know (a stupid idea). The bug dates back to about 5 years afaict. Misc: - Fix hostfs parsing when the mount request comes in via the legacy mount api. In the legacy mount api hostfs allows to specify the host directory mount without any key. Restore that behavior" * tag 'vfs-6.11-rc1.fixes.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: hostfs: fix the host directory parse when mounting. fs: don't allow non-init s_user_ns for filesystems without FS_USERNS_MOUNT
2024-07-27hostfs: fix the host directory parse when mounting.Hongbo Li
hostfs not keep the host directory when mounting. When the host directory is none (default), fc->source is used as the host root directory, and this is wrong. Here we use `parse_monolithic` to handle the old mount path for parsing the root directory. For new mount path, The `parse_param` is used for the host directory parse. Reported-and-tested-by: Maciej Żenczykowski <maze@google.com> Fixes: cd140ce9f611 ("hostfs: convert hostfs to use the new mount API") Link: https://lore.kernel.org/all/CANP3RGceNzwdb7w=vPf5=7BCid5HVQDmz1K5kC9JG42+HVAh_g@mail.gmail.com/ Cc: Christian Brauner <brauner@kernel.org> Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Link: https://lore.kernel.org/r/20240725065130.1821964-1-lihongbo22@huawei.com [brauner: minor fixes] Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-07-25Merge tag 'uml-for-linus-6.11-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux Pull UML updates from Richard Weinberger: - Support for preemption - i386 Rust support - Huge cleanup by Benjamin Berg - UBSAN support - Removal of dead code * tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (41 commits) um: vector: always reset vp->opened um: vector: remove vp->lock um: register power-off handler um: line: always fill *error_out in setup_one_line() um: remove pcap driver from documentation um: Enable preemption in UML um: refactor TLB update handling um: simplify and consolidate TLB updates um: remove force_flush_all from fork_handler um: Do not flush MM in flush_thread um: Delay flushing syscalls until the thread is restarted um: remove copy_context_skas0 um: remove LDT support um: compress memory related stub syscalls while adding them um: Rework syscall handling um: Add generic stub_syscall6 function um: Create signal stack memory assignment in stub_data um: Remove stub-data.h include from common-offsets.h um: time-travel: fix signal blocking race/hang um: time-travel: remove time_exit() ...
2024-07-24hostfs: fix folio conversionLinus Torvalds
Commit e3ec0fe944d2 ("hostfs: Convert hostfs_read_folio() to use a folio") simplified hostfs_read_folio(), but in the process of converting to using folios natively also mis-used the folio_zero_tail() function due to the very confusing API of that function. Very arguably it's folio_zero_tail() API itself that is buggy, since it would make more sense (and the documentation kind of implies) that the third argument would be the pointer to the beginning of the folio buffer. But no, the third argument to folio_zero_tail() is where we should start zeroing the tail (even if we already also pass in the offset separately as the second argument). So fix the hostfs caller, and we can leave any folio_zero_tail() sanity cleanup for later. Reported-and-tested-by: Maciej Żenczykowski <maze@google.com> Fixes: e3ec0fe944d2 ("hostfs: Convert hostfs_read_folio() to use a folio") Link: https://lore.kernel.org/all/CANP3RGceNzwdb7w=vPf5=7BCid5HVQDmz1K5kC9JG42+HVAh_g@mail.gmail.com/ Cc: Matthew Wilcox <willy@infradead.org> Cc: Christian Brauner <brauner@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-07-15Merge tag 'vfs-6.11.mount.api' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs mount API updates from Christian Brauner: - Add a generic helper to parse uid and gid mount options. Currently we open-code the same logic in various filesystems which is error prone, especially since the verification of uid and gid mount options is a sensitive operation in the face of idmappings. Add a generic helper and convert all filesystems over to it. Make sure that filesystems that are mountable in unprivileged containers verify that the specified uid and gid can be represented in the owning namespace of the filesystem. - Convert hostfs to the new mount api. * tag 'vfs-6.11.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fuse: Convert to new uid/gid option parsing helpers fuse: verify {g,u}id mount options correctly fat: Convert to new uid/gid option parsing helpers fat: Convert to new mount api fat: move debug into fat_mount_options vboxsf: Convert to new uid/gid option parsing helpers tracefs: Convert to new uid/gid option parsing helpers smb: client: Convert to new uid/gid option parsing helpers tmpfs: Convert to new uid/gid option parsing helpers ntfs3: Convert to new uid/gid option parsing helpers isofs: Convert to new uid/gid option parsing helpers hugetlbfs: Convert to new uid/gid option parsing helpers ext4: Convert to new uid/gid option parsing helpers exfat: Convert to new uid/gid option parsing helpers efivarfs: Convert to new uid/gid option parsing helpers debugfs: Convert to new uid/gid option parsing helpers autofs: Convert to new uid/gid option parsing helpers fs_parse: add uid & gid option option parsing helpers hostfs: Add const qualifier to host_root in hostfs_fill_super() hostfs: convert hostfs to use the new mount API
2024-07-03hostfs: add missing MODULE_DESCRIPTION() macroJeff Johnson
With ARCH=um, make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in fs/hostfs/hostfs.o Add the missing invocation of the MODULE_DESCRIPTION() macro. Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com> Link: https://patch.msgid.link/20240702-md-um-fs-hostfs-v1-1-fd2b565027e7@quicinc.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03hostfs: fix dev_t handlingJohannes Berg
dev_t is a kernel type and may have different definitions in kernel and userspace. On 32-bit x86 this currently makes the stat structure being 4 bytes longer in the user code, causing stack corruption. However, this is (potentially) not the only problem, since dev_t is a different type on user/kernel side, so we don't know that the major/minor encoding isn't also different. Decode/encode it instead to address both problems. Cc: stable@vger.kernel.org Fixes: 74ce793bcbde ("hostfs: Fix ephemeral inodes") Link: https://patch.msgid.link/20240702092440.acc960585dd5.Id0767e12f562a69c6cd3c3262dc3d765db350cf6@changeid Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-06-13hostfs: Add const qualifier to host_root in hostfs_fill_super()Nathan Chancellor
After the recent conversion to the new mount API, there is a warning when building hostfs (which may be upgraded to an error via CONFIG_WERROR=y): fs/hostfs/hostfs_kern.c: In function 'hostfs_fill_super': fs/hostfs/hostfs_kern.c:942:27: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] 942 | char *host_root = fc->source; | ^~ Add the 'const' qualifier, as host_root will not be modified after its assignment. Move the assignment to keep the existing reverse Christmas tree order intact. Fixes: cd140ce9f611 ("hostfs: convert hostfs to use the new mount API") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240611-hostfs-fix-mount-api-conversion-v1-1-ef75bbc77f44@kernel.org Acked-by: Richard Weinberger <richard@nod.at> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-06-03hostfs: convert hostfs to use the new mount APIHongbo Li
Convert the hostfs filesystem to the new internal mount API as the old one will be obsoleted and removed. This allows greater flexibility in communication of mount parameters between userspace, the VFS and the filesystem. See Documentation/filesystems/mount_api.txt for more information. Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Link: https://lore.kernel.org/r/20240530120111.3794664-1-lihongbo22@huawei.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-05-31hostfs: Convert hostfs_read_folio() to use a folioMatthew Wilcox (Oracle)
Remove the use of page APIs, including setting/clearing the error flag which is never checked on hostfs folios. This does not include support for large folios as kmap_local_folio() maps only one page at a time. Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: linux-um@lists.infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://lore.kernel.org/r/20240530202110.2653630-8-willy@infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-12-21hostfs: use d_splice_alias() calling conventions to simplify failure exitsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-10-18hostfs: convert to new timestamp accessorsJeff Layton
Convert to using the new inode timestamp accessor functions. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20231004185347.80880-41-jlayton@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-24hostfs: convert to ctime accessor functionsJeff Layton
In later patches, we're going to change how the inode's ctime field is used. Switch to using accessor functions instead of raw accesses of inode->i_ctime. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230705190309.579783-48-jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-27Merge tag 'landlock-6.5-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux Pull landlock updates from Mickaël Salaün: "Add support for Landlock to UML. To do this, this fixes the way hostfs manages inodes according to the underlying filesystem [1]. They are now properly handled as for other filesystems, which enables Landlock support (and probably other features). This also extends Landlock's tests with 6 pseudo filesystems, including hostfs" [1] https://lore.kernel.org/all/20230612191430.339153-1-mic@digikod.net/ * tag 'landlock-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux: selftests/landlock: Add hostfs tests selftests/landlock: Add tests for pseudo filesystems selftests/landlock: Make mounts configurable selftests/landlock: Add supports_filesystem() helper selftests/landlock: Don't create useless file layouts hostfs: Fix ephemeral inodes
2023-06-12hostfs: Fix ephemeral inodesMickaël Salaün
hostfs creates a new inode for each opened or created file, which created useless inode allocations and forbade identifying a host file with a kernel inode. Fix this uncommon filesystem behavior by tying kernel inodes to host file's inode and device IDs. Even if the host filesystem inodes may be recycled, this cannot happen while a file referencing it is opened, which is the case with hostfs. It should be noted that hostfs inode IDs may not be unique for the same hostfs superblock because multiple host's (backed) superblocks may be used. Delete inodes when dropping them to force backed host's file descriptors closing. This enables to entirely remove ARCH_EPHEMERAL_INODES, and then makes Landlock fully supported by UML. This is very useful for testing changes. These changes also factor out and simplify some helpers thanks to the new hostfs_inode_update() and the hostfs_iget() revamp: read_name(), hostfs_create(), hostfs_lookup(), hostfs_mknod(), and hostfs_fill_sb_common(). A following commit with new Landlock tests check this new hostfs inode consistency. Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Johannes Berg <johannes@sipsolutions.net> Acked-by: Richard Weinberger <richard@nod.at> Link: https://lore.kernel.org/r/20230612191430.339153-2-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2023-05-24splice: Use filemap_splice_read() instead of generic_file_splice_read()David Howells
Replace pointers to generic_file_splice_read() with calls to filemap_splice_read(). Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Al Viro <viro@zeniv.linux.org.uk> cc: David Hildenbrand <david@redhat.com> cc: John Hubbard <jhubbard@nvidia.com> cc: linux-mm@kvack.org cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20230522135018.2742245-29-dhowells@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-20um: hostfs: define our own API boundaryJohannes Berg
Instead of exporting the set of functions provided by glibc that are needed for hostfs_user.c, just build that into the kernel image whenever hostfs is built, and then export _those_ functions cleanly, to be independent of the libc implementation. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2023-03-01Merge tag 'uml-for-linus-6.3-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux Pull UML updates from Richard Weinberger: - Add support for rust (yay!) - Add support for LTO - Add platform bus support to virtio-pci - Various virtio fixes - Coding style, spelling cleanups * tag 'uml-for-linus-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (27 commits) Documentation: rust: Fix arch support table uml: vector: Remove unused definitions VECTOR_{WRITE,HEADERS} um: virt-pci: properly remove PCI device from bus um: virtio_uml: move device breaking into workqueue um: virtio_uml: mark device as unregistered when breaking it um: virtio_uml: free command if adding to virtqueue failed UML: define RUNTIME_DISCARD_EXIT virt-pci: add platform bus support um-virt-pci: Make max delay configurable um: virt-pci: implement pcibios_get_phb_of_node() um: Support LTO um: put power options in a menu um: Use CFLAGS_vmlinux um: Prevent building modules incompatible with MODVERSIONS um: Avoid pcap multiple definition errors um: Make the definition of cpu_data more compatible x86: um: vdso: Add '%rcx' and '%r11' to the syscall clobber list rust: arch/um: Add support for CONFIG_RUST under x86_64 UML rust: arch/um: Disable FP/SIMD instruction to match x86 rust: arch/um: Use 'pie' relocation mode under UML ...
2023-02-26Merge tag 'kbuild-v6.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Change V=1 option to print both short log and full command log - Allow V=1 and V=2 to be combined as V=12 - Make W=1 detect wrong .gitignore files - Tree-wide cleanups for unused command line arguments passed to Clang - Stop using -Qunused-arguments with Clang - Make scripts/setlocalversion handle only correct release tags instead of any arbitrary annotated tag - Create Debian and RPM source packages without cleaning the source tree - Various cleanups for packaging * tag 'kbuild-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (74 commits) kbuild: rpm-pkg: remove unneeded KERNELRELEASE from modules/headers_install docs: kbuild: remove description of KBUILD_LDS_MODULE .gitattributes: use 'dts' diff driver for *.dtso files kbuild: deb-pkg: improve the usability of source package kbuild: deb-pkg: fix binary-arch and clean in debian/rules kbuild: tar-pkg: use tar rules in scripts/Makefile.package kbuild: make perf-tar*-src-pkg work without relying on git kbuild: deb-pkg: switch over to source format 3.0 (quilt) kbuild: deb-pkg: make .orig tarball a hard link if possible kbuild: deb-pkg: hide KDEB_SOURCENAME from Makefile kbuild: srcrpm-pkg: create source package without cleaning kbuild: rpm-pkg: build binary packages from source rpm kbuild: deb-pkg: create source package without cleaning kbuild: add a tool to list files ignored by git Documentation/llvm: add Chimera Linux, Google and Meta datacenters setlocalversion: use only the correct release tag for git-describe setlocalversion: clean up the construction of version output .gitignore: ignore *.cover and *.mbx kbuild: remove --include-dir MAKEFLAG from top Makefile kbuild: fix trivial typo in comment ...
2023-02-05kbuild: remove --include-dir MAKEFLAG from top MakefileMasahiro Yamada
I added $(srctree)/ to some included Makefiles in the following commits: - 3204a7fb98a3 ("kbuild: prefix $(srctree)/ to some included Makefiles") - d82856395505 ("kbuild: do not require sub-make for separate output tree builds") They were a preparation for removing --include-dir flag. I have never thought --include-dir useful. Rather, it _is_ harmful. For example, run the following commands: $ make -s ARCH=x86 mrproper defconfig $ make ARCH=arm O=foo dtbs make[1]: Entering directory '/tmp/linux/foo' HOSTCC scripts/basic/fixdep Error: kernelrelease not valid - run 'make prepare' to update it UPD include/config/kernel.release make[1]: Leaving directory '/tmp/linux/foo' The first command configures the source tree for x86. The next command tries to build ARM device trees in the separate foo/ directory - this must stop because the directory foo/ has not been configured yet. However, due to --include-dir=$(abs_srctree), the top Makefile includes the wrong include/config/auto.conf from the source tree and continues building. Kbuild traverses the directory tree, but of course it does not work correctly. The Error message is also pointless - 'make prepare' does not help at all for fixing the issue. This commit fixes more arch Makefile, and finally removes --include-dir from the top Makefile. There are more breakages under drivers/, but I do not volunteer to fix them all. I just moved --include-dir to drivers/Makefile. With this commit, the second command will stop with a sensible message. $ make -s ARCH=x86 mrproper defconfig $ make ARCH=arm O=foo dtbs make[1]: Entering directory '/tmp/linux/foo' SYNC include/config/auto.conf.cmd *** *** The source tree is not clean, please run 'make ARCH=arm mrproper' *** in /tmp/linux *** make[2]: *** [../Makefile:646: outputmakefile] Error 1 /tmp/linux/Makefile:770: include/config/auto.conf.cmd: No such file or directory make[1]: *** [/tmp/linux/Makefile:793: include/config/auto.conf.cmd] Error 2 make[1]: Leaving directory '/tmp/linux/foo' make: *** [Makefile:226: __sub-make] Error 2 Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-02-01hostfs: Replace kmap() with kmap_local_page()Fabio M. De Francesco
The use of kmap() is being deprecated in favor of kmap_local_page(). There are two main problems with kmap(): (1) It comes with an overhead as the mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap’s pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and still valid. Therefore, replace kmap() with kmap_local_page() in hostfs_kern.c, it being the only file with kmap() call sites currently left in fs/hostfs. Cc: "Venkataramanan, Anirudh" <anirudh.venkataramanan@intel.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2023-01-19fs: port ->permission() to pass mnt_idmapChristian Brauner
Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19fs: port ->rename() to pass mnt_idmapChristian Brauner
Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19fs: port ->mknod() to pass mnt_idmapChristian Brauner
Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19fs: port ->mkdir() to pass mnt_idmapChristian Brauner
Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19fs: port ->symlink() to pass mnt_idmapChristian Brauner
Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19fs: port ->create() to pass mnt_idmapChristian Brauner
Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19fs: port ->setattr() to pass mnt_idmapChristian Brauner
Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-09-19hostfs: move from strlcpy with unused retval to strscpyWolfram Sang
Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2022-08-02hostfs: Handle page write errors correctlyMatthew Wilcox (Oracle)
If a page can't be written back, we need to call mapping_set_error(), not clear the page's Uptodate flag. Also remove the clearing of PageError on success; that flag is used for read errors, not write errors. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-05-09hostfs: Convert hostfs to read_folioMatthew Wilcox (Oracle)
This is a "weak" conversion which converts straight back to using pages. A full conversion should be performed at some point, hopefully by someone familiar with the filesystem. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-05-08fs: Remove flags parameter from aops->write_beginMatthew Wilcox (Oracle)
There are no more aop flags left, so remove the parameter. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>