kernel/linux.git/fs/hostfs, branch v6.18.21

hostfs: Fix only passing host root in boot stage with new mount

2025-10-21T12:22:42+00:00

In the old mount proceedure, hostfs could only pass root directory during boot. This is because it constructed the root directory using the @root_ino event without any mount options. However, when using it with the new mount API, this step is no longer triggered. As a result, if users mounts without specifying any mount options, the @host_root_path remains uninitialized. To prevent this issue, the @host_root_path should be initialized at the time of allocation. Reported-by: Geoffrey Thorpe Closes: https://lore.kernel.org/all/643333a0-f434-42fb-82ac-d25a0b56f3b7@geoffthorpe.net/ Fixes: cd140ce9f611 ("hostfs: convert hostfs to use the new mount API") Signed-off-by: Hongbo Li Link: https://patch.msgid.link/20251011092235.29880-1-lihongbo22@huawei.com Signed-off-by: Christian Brauner

fs: rename generic_delete_inode() and generic_drop_inode()

2025-09-15T14:09:42+00:00

generic_delete_inode() is rather misleading for what the routine is doing. inode_just_drop() should be much clearer. The new naming is inconsistent with generic_drop_inode(), so rename that one as well with inode_ as the suffix. No functional changes. Signed-off-by: Mateusz Guzik Reviewed-by: Jan Kara Signed-off-by: Christian Brauner

Merge tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-07-28T20:43:25+00:00

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

Merge tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-07-28T18:22:56+00:00

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 ...

fs: change write_begin/write_end interface to take struct kiocb *

2025-07-16T12:48:18+00:00

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 Link: https://lore.kernel.org/20250716093559.217344-4-chentaotao@didiglobal.com Signed-off-by: Christian Brauner

fs: convert simple use of generic_file_*_mmap() to .mmap_prepare()

2025-06-17T11:47:45+00:00

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 Link: https://lore.kernel.org/c7dc90e44a9e75e750939ea369290d6e441a18e6.1750099179.git.lorenzo.stoakes@oracle.com Reviewed-by: Jan Kara Reviewed-by: Viacheslav Dubeyko Signed-off-by: Christian Brauner

devpts, sunrpc, hostfs: don't bother with ->d_op

2025-06-11T17:40:04+00:00

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 Signed-off-by: Al Viro

new helper: set_default_d_op()

2025-06-11T02:21:16+00:00

... 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 Signed-off-by: Al Viro

Merge tag 'uml-for-linux-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux

2025-04-02T19:25:03+00:00

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

um: hostfs: avoid issues on inode number reuse by host

2025-03-18T10:04:13+00:00

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 Reviewed-by: Mickaël Salaün Tested-by: Mickaël Salaün Link: https://patch.msgid.link/20250214092822.1241575-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg