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* ovl: fix file reference leak when submitting aioAmir Goldstein2023-10-021-2/+0
| | | | | | | | | | | Commit 724768a39374 ("ovl: fix incorrect fdput() on aio completion") took a refcount on real file before submitting aio, but forgot to avoid clearing FDPUT_FPUT from real.flags stack variable. This can result in a file reference leak. Fixes: 724768a39374 ("ovl: fix incorrect fdput() on aio completion") Reported-by: Gil Lev <contact@levgil.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
* Merge tag 'v6.6-rc4.vfs.fixes' of ↵Linus Torvalds2023-09-261-0/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Pull vfs fixes from Christian Brauner: "This contains the usual miscellaneous fixes and cleanups for vfs and individual fses: Fixes: - Revert ki_pos on error from buffered writes for direct io fallback - Add missing documentation for block device and superblock handling for changes merged this cycle - Fix reiserfs flexible array usage - Ensure that overlayfs sets ctime when setting mtime and atime - Disable deferred caller completions with overlayfs writes until proper support exists Cleanups: - Remove duplicate initialization in pipe code - Annotate aio kioctx_table with __counted_by" * tag 'v6.6-rc4.vfs.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: overlayfs: set ctime when setting mtime and atime ntfs3: put resources during ntfs_fill_super() ovl: disable IOCB_DIO_CALLER_COMP porting: document superblock as block device holder porting: document new block device opening order fs/pipe: remove duplicate "offset" initializer fs-writeback: do not requeue a clean inode having skipped pages aio: Annotate struct kioctx_table with __counted_by direct_write_fallback(): on error revert the ->ki_pos update from buffered write reiserfs: Replace 1-element array with C99 style flex-array
| * ovl: disable IOCB_DIO_CALLER_COMPJens Axboe2023-09-251-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | overlayfs copies the kiocb flags when it sets up a new kiocb to handle a write, but it doesn't properly support dealing with the deferred caller completions of the kiocb. This means it doesn't get the final write completion value, and hence will complete the write with '0' as the result. We could support the caller completions in overlayfs, but for now let's just disable them in the generated write kiocb. Reported-by: Zorro Lang <zlang@redhat.com> Link: https://lore.kernel.org/io-uring/20230924142754.ejwsjen5pvyc32l4@dell-per750-06-vm-08.rhts.eng.pek2.redhat.com/ Fixes: 8c052fb3002e ("iomap: support IOCB_DIO_CALLER_COMP") Signed-off-by: Jens Axboe <axboe@kernel.dk> Message-Id: <71897125-e570-46ce-946a-d4729725e28f@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
* | ovl: fix incorrect fdput() on aio completionAmir Goldstein2023-09-041-6/+3
|/ | | | | | | | | | | | | | | ovl_{read,write}_iter() always call fdput(real) to put one or zero refcounts of the real file, but for aio, whether it was submitted or not, ovl_aio_put() also calls fdput(), which is not balanced. This is only a problem in the less common case when FDPUT_FPUT flag is set. To fix the problem use get_file() to take file refcount and use fput() instead of fdput() in ovl_aio_put(). Fixes: 2406a307ac7d ("ovl: implement async IO routines") Cc: <stable@vger.kernel.org> # v5.6 Reviewed-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
* Merge tag 'ovl-update-6.6' of ↵Linus Torvalds2023-08-301-4/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs Pull overlayfs updates from Amir Goldstein: - add verification feature needed by composefs (Alexander Larsson) - improve integration of overlayfs and fanotify (Amir Goldstein) - fortify some overlayfs code (Andrea Righi) * tag 'ovl-update-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs: ovl: validate superblock in OVL_FS() ovl: make consistent use of OVL_FS() ovl: Kconfig: introduce CONFIG_OVERLAY_FS_DEBUG ovl: auto generate uuid for new overlay filesystems ovl: store persistent uuid/fsid with uuid=on ovl: add support for unique fsid per instance ovl: support encoding non-decodable file handles ovl: Handle verity during copy-up ovl: Validate verity xattr when resolving lowerdata ovl: Add versioned header for overlay.metacopy xattr ovl: Add framework for verity support
| * ovl: Validate verity xattr when resolving lowerdataAlexander Larsson2023-08-121-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new digest field in the metacopy xattr is used during lookup to record whether the header contained a digest in the OVL_HAS_DIGEST flags. When accessing file data the first time, if OVL_HAS_DIGEST is set, we reload the metadata and check that the source lowerdata inode matches the specified digest in it (according to the enabled verity options). If the verity check passes we store this info in the inode flags as OVL_VERIFIED_DIGEST, so that we can avoid doing it again if the inode remains in memory. The verification is done in ovl_maybe_validate_verity() which needs to be called in the same places as ovl_maybe_lookup_lowerdata(), so there is a new ovl_verify_lowerdata() helper that calls these in the right order, and all current callers of ovl_maybe_lookup_lowerdata() are changed to call it instead. Signed-off-by: Alexander Larsson <alexl@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
* | Merge tag 'v6.6-vfs.misc' of ↵Linus Torvalds2023-08-281-8/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "This contains the usual miscellaneous features, cleanups, and fixes for vfs and individual filesystems. Features: - Block mode changes on symlinks and rectify our broken semantics - Report file modifications via fsnotify() for splice - Allow specifying an explicit timeout for the "rootwait" kernel command line option. This allows to timeout and reboot instead of always waiting indefinitely for the root device to show up - Use synchronous fput for the close system call Cleanups: - Get rid of open-coded lockdep workarounds for async io submitters and replace it all with a single consolidated helper - Simplify epoll allocation helper - Convert simple_write_begin and simple_write_end to use a folio - Convert page_cache_pipe_buf_confirm() to use a folio - Simplify __range_close to avoid pointless locking - Disable per-cpu buffer head cache for isolated cpus - Port ecryptfs to kmap_local_page() api - Remove redundant initialization of pointer buf in pipe code - Unexport the d_genocide() function which is only used within core vfs - Replace printk(KERN_ERR) and WARN_ON() with WARN() Fixes: - Fix various kernel-doc issues - Fix refcount underflow for eventfds when used as EFD_SEMAPHORE - Fix a mainly theoretical issue in devpts - Check the return value of __getblk() in reiserfs - Fix a racy assert in i_readcount_dec - Fix integer conversion issues in various functions - Fix LSM security context handling during automounts that prevented NFS superblock sharing" * tag 'v6.6-vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (39 commits) cachefiles: use kiocb_{start,end}_write() helpers ovl: use kiocb_{start,end}_write() helpers aio: use kiocb_{start,end}_write() helpers io_uring: use kiocb_{start,end}_write() helpers fs: create kiocb_{start,end}_write() helpers fs: add kerneldoc to file_{start,end}_write() helpers io_uring: rename kiocb_end_write() local helper splice: Convert page_cache_pipe_buf_confirm() to use a folio libfs: Convert simple_write_begin and simple_write_end to use a folio fs/dcache: Replace printk and WARN_ON by WARN fs/pipe: remove redundant initialization of pointer buf fs: Fix kernel-doc warnings devpts: Fix kernel-doc warnings doc: idmappings: fix an error and rephrase a paragraph init: Add support for rootwait timeout parameter vfs: fix up the assert in i_readcount_dec fs: Fix one kernel-doc comment docs: filesystems: idmappings: clarify from where idmappings are taken fs/buffer.c: disable per-CPU buffer_head cache for isolated CPUs vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing ...
| * | ovl: use kiocb_{start,end}_write() helpersAmir Goldstein2023-08-211-8/+2
| |/ | | | | | | | | | | | | | | | | | | | | Use helpers instead of the open coded dance to silence lockdep warnings. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Message-Id: <20230817141337.1025891-7-amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
* / overlayfs: convert to ctime accessor functionsJeff Layton2023-07-241-2/+5
|/ | | | | | | | | | | | 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. Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230705190309.579783-64-jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
* Merge tag 'ovl-update-6.5' of ↵Linus Torvalds2023-06-291-2/+19
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs Pull overlayfs update from Amir Goldstein: - fix two NULL pointer deref bugs (Zhihao Cheng) - add support for "data-only" lower layers destined to be used by composefs - port overlayfs to the new mount api (Christian Brauner) * tag 'ovl-update-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs: (26 commits) ovl: add Amir as co-maintainer ovl: reserve ability to reconfigure mount options with new mount api ovl: modify layer parameter parsing ovl: port to new mount api ovl: factor out ovl_parse_options() helper ovl: store enum redirect_mode in config instead of a string ovl: pass ovl_fs to xino helpers ovl: clarify ovl_get_root() semantics ovl: negate the ofs->share_whiteout boolean ovl: check type and offset of struct vfsmount in ovl_entry ovl: implement lazy lookup of lowerdata in data-only layers ovl: prepare for lazy lookup of lowerdata inode ovl: prepare to store lowerdata redirect for lazy lowerdata lookup ovl: implement lookup in data-only layers ovl: introduce data-only lower layers ovl: remove unneeded goto instructions ovl: deduplicate lowerdata and lowerstack[] ovl: deduplicate lowerpath and lowerstack[] ovl: move ovl_entry into ovl_inode ovl: factor out ovl_free_entry() and ovl_stack_*() helpers ...
| * ovl: implement lazy lookup of lowerdata in data-only layersAmir Goldstein2023-06-191-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Defer lookup of lowerdata in the data-only layers to first data access or before copy up. We perform lowerdata lookup before copy up even if copy up is metadata only copy up. We can further optimize this lookup later if needed. We do best effort lazy lookup of lowerdata for d_real_inode(), because this interface does not expect errors. The only current in-tree caller of d_real_inode() is trace_uprobe and this caller is likely going to be followed reading from the file, before placing uprobes on offset within the file, so lowerdata should be available when setting the uprobe. Tested-by: kernel test robot <oliver.sang@intel.com> Reviewed-by: Alexander Larsson <alexl@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: prepare for lazy lookup of lowerdata inodeAmir Goldstein2023-06-191-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the code handle the case of numlower > 1 and missing lowerdata dentry gracefully. Missing lowerdata dentry is an indication for lazy lookup of lowerdata and in that case the lowerdata_redirect path is stored in ovl_inode. Following commits will defer lookup and perform the lazy lookup on access. Reviewed-by: Alexander Larsson <alexl@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | Merge tag 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linuxLinus Torvalds2023-06-261-1/+22
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull splice updates from Jens Axboe: "This kills off ITER_PIPE to avoid a race between truncate, iov_iter_revert() on the pipe and an as-yet incomplete DMA to a bio with unpinned/unref'ed pages from an O_DIRECT splice read. This causes memory corruption. Instead, we either use (a) filemap_splice_read(), which invokes the buffered file reading code and splices from the pagecache into the pipe; (b) copy_splice_read(), which bulk-allocates a buffer, reads into it and then pushes the filled pages into the pipe; or (c) handle it in filesystem-specific code. Summary: - Rename direct_splice_read() to copy_splice_read() - Simplify the calculations for the number of pages to be reclaimed in copy_splice_read() - Turn do_splice_to() into a helper, vfs_splice_read(), so that it can be used by overlayfs and coda to perform the checks on the lower fs - Make vfs_splice_read() jump to copy_splice_read() to handle direct-I/O and DAX - Provide shmem with its own splice_read to handle non-existent pages in the pagecache. We don't want a ->read_folio() as we don't want to populate holes, but filemap_get_pages() requires it - Provide overlayfs with its own splice_read to call down to a lower layer as overlayfs doesn't provide ->read_folio() - Provide coda with its own splice_read to call down to a lower layer as coda doesn't provide ->read_folio() - Direct ->splice_read to copy_splice_read() in tty, procfs, kernfs and random files as they just copy to the output buffer and don't splice pages - Provide wrappers for afs, ceph, ecryptfs, ext4, f2fs, nfs, ntfs3, ocfs2, orangefs, xfs and zonefs to do locking and/or revalidation - Make cifs use filemap_splice_read() - Replace pointers to generic_file_splice_read() with pointers to filemap_splice_read() as DIO and DAX are handled in the caller; filesystems can still provide their own alternate ->splice_read() op - Remove generic_file_splice_read() - Remove ITER_PIPE and its paraphernalia as generic_file_splice_read was the only user" * tag 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linux: (31 commits) splice: kdoc for filemap_splice_read() and copy_splice_read() iov_iter: Kill ITER_PIPE splice: Remove generic_file_splice_read() splice: Use filemap_splice_read() instead of generic_file_splice_read() cifs: Use filemap_splice_read() trace: Convert trace/seq to use copy_splice_read() zonefs: Provide a splice-read wrapper xfs: Provide a splice-read wrapper orangefs: Provide a splice-read wrapper ocfs2: Provide a splice-read wrapper ntfs3: Provide a splice-read wrapper nfs: Provide a splice-read wrapper f2fs: Provide a splice-read wrapper ext4: Provide a splice-read wrapper ecryptfs: Provide a splice-read wrapper ceph: Provide a splice-read wrapper afs: Provide a splice-read wrapper 9p: Add splice_read wrapper net: Make sock_splice_read() use copy_splice_read() by default tty, proc, kernfs, random: Use copy_splice_read() ...
| * | overlayfs: Implement splice-readDavid Howells2023-05-241-1/+22
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement splice-read for overlayfs by passing the request down a layer rather than going through generic_file_splice_read() which is going to be changed to assume that ->read_folio() is present on buffered files. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Christian Brauner <brauner@kernel.org> cc: Christoph Hellwig <hch@lst.de> cc: Jens Axboe <axboe@kernel.dk> cc: Al Viro <viro@zeniv.linux.org.uk> cc: John Hubbard <jhubbard@nvidia.com> cc: David Hildenbrand <david@redhat.com> cc: Matthew Wilcox <willy@infradead.org> cc: Miklos Szeredi <miklos@szeredi.hu> cc: Amir Goldstein <amir73il@gmail.com> cc: linux-unionfs@vger.kernel.org cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org Link: https://lore.kernel.org/r/20230522135018.2742245-11-dhowells@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | ovl: enable fsnotify events on underlying real filesAmir Goldstein2023-06-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Overlayfs creates the real underlying files with fake f_path, whose f_inode is on the underlying fs and f_path on overlayfs. Those real files were open with FMODE_NONOTIFY, because fsnotify code was not prapared to handle fsnotify hooks on files with fake path correctly and fanotify would report unexpected event->fd with fake overlayfs path, when the underlying fs was being watched. Teach fsnotify to handle events on the real files, and do not set real files to FMODE_NONOTIFY to allow operations on real file (e.g. open, access, modify, close) to generate async and permission events. Because fsnotify does not have notifications on address space operations, we do not need to worry about ->vm_file not reporting events to a watched overlayfs when users are accessing a mapped overlayfs file. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Message-Id: <20230615112229.2143178-6-amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
* | fs: use backing_file container for internal files with "fake" f_pathAmir Goldstein2023-06-191-2/+2
|/ | | | | | | | | | | | | | Overlayfs uses open_with_fake_path() to allocate internal kernel files, with a "fake" path - whose f_path is not on the same fs as f_inode. Allocate a container struct backing_file for those internal files, that is used to hold the "fake" ovl path along with the real path. backing_file_real_path() can be used to access the stored real path. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Message-Id: <20230615112229.2143178-5-amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
* fs: port inode_owner_or_capable() to mnt_idmapChristian Brauner2023-01-191-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* fs: port ->permission() to pass mnt_idmapChristian Brauner2023-01-191-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge tag 'ovl-update-6.2' of ↵Linus Torvalds2022-12-131-1/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs update from Miklos Szeredi: - Fix a couple of bugs found by syzbot - Don't ingore some open flags set by fcntl(F_SETFL) - Fix failure to create a hard link in certain cases - Use type safe helpers for some mnt_userns transformations - Improve performance of mount - Misc cleanups * tag 'ovl-update-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: Kconfig: Fix spelling mistake "undelying" -> "underlying" ovl: use inode instead of dentry where possible ovl: Add comment on upperredirect reassignment ovl: use plain list filler in indexdir and workdir cleanup ovl: do not reconnect upper index records in ovl_indexdir_cleanup() ovl: fix comment typos ovl: port to vfs{g,u}id_t and associated helpers ovl: Use ovl mounter's fsuid and fsgid in ovl_link() ovl: Use "buf" flexible array for memcpy() destination ovl: update ->f_iocb_flags when ovl_change_flags() modifies ->f_flags ovl: fix use inode directly in rcu-walk mode
| * ovl: fix comment typosJiangshan Yi2022-12-081-1/+1
| | | | | | | | | | | | | | | | Fix two typos. Reported-by: k2ci <kernel-bot@kylinos.cn> Signed-off-by: Jiangshan Yi <yijiangshan@kylinos.cn> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: update ->f_iocb_flags when ovl_change_flags() modifies ->f_flagsAl Viro2022-11-281-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | ovl_change_flags() is an open-coded variant of fs/fcntl.c:setfl() and it got missed by commit 164f4064ca81 ("keep iocb_flags() result cached in struct file"); the same change applies there. Reported-by: Pierre Labastie <pierre.labastie@neuf.fr> Fixes: 164f4064ca81 ("keep iocb_flags() result cached in struct file") Cc: <stable@vger.kernel.org> # v6.0 Link: https://bugzilla.kernel.org/show_bug.cgi?id=216738 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | ovl: remove privs in ovl_fallocate()Amir Goldstein2022-10-181-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | Underlying fs doesn't remove privs because fallocate is called with privileged mounter credentials. This fixes some failure in fstests generic/683..687. Fixes: aab8848cee5e ("ovl: add ovl_fallocate()") Acked-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
* | ovl: remove privs in ovl_copyfile()Amir Goldstein2022-10-181-2/+14
|/ | | | | | | | | | | | Underlying fs doesn't remove privs because copy_range/remap_range are called with privileged mounter credentials. This fixes some failures in fstest generic/673. Fixes: 8ede205541ff ("ovl: add reflink/copyfile/dedup support") Acked-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
* overlayfs: constify pathAl Viro2022-09-011-1/+1
| | | | | Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge tag 'ovl-update-5.19' of ↵Linus Torvalds2022-05-301-19/+24
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: - Support idmapped layers in overlayfs (Christian Brauner) - Add a fix to exportfs that is relevant to open_by_handle_at(2) as well - Introduce new lookup helpers that allow passing mnt_userns into inode_permission() * tag 'ovl-update-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: support idmapped layers ovl: handle idmappings in ovl_xattr_{g,s}et() ovl: handle idmappings in layer open helpers ovl: handle idmappings in ovl_permission() ovl: use ovl_copy_{real,upper}attr() wrappers ovl: store lower path in ovl_inode ovl: handle idmappings for layer lookup ovl: handle idmappings for layer fileattrs ovl: use ovl_path_getxattr() wrapper ovl: use ovl_lookup_upper() wrapper ovl: use ovl_do_notify_change() wrapper ovl: pass layer mnt to ovl_open_realfile() ovl: pass ofs to setattr operations ovl: handle idmappings in creation operations ovl: add ovl_upper_mnt_userns() wrapper ovl: pass ofs to creation operations ovl: use wrappers to all vfs_*xattr() calls exportfs: support idmapped mounts fs: add two trivial lookup helpers
| * ovl: handle idmappings in layer open helpersChristian Brauner2022-04-281-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | In earlier patches we already passed down the relevant upper or lower path to ovl_open_realfile(). Now let the open helpers actually take the idmapping of the relevant mount into account when checking permissions. This is needed to support idmapped base layers with overlay. Cc: <linux-unionfs@vger.kernel.org> Tested-by: Giuseppe Scrivano <gscrivan@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: use ovl_copy_{real,upper}attr() wrappersChristian Brauner2022-04-281-8/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When copying inode attributes from the upper or lower layer to ovl inodes we need to take the upper or lower layer's mount's idmapping into account. In a lot of places we call ovl_copyattr() only on upper inodes and in some we call it on either upper or lower inodes. Split this into two separate helpers. The first one should only be called on upper inodes and is thus called ovl_copy_upperattr(). The second one can be called on upper or lower inodes. We add ovl_copy_realattr() for this task. The new helper makes use of the previously added ovl_i_path_real() helper. This is needed to support idmapped base layers with overlay. When overlay copies the inode information from an upper or lower layer to the relevant overlay inode it will apply the idmapping of the upper or lower layer when doing so. The ovl inode ownership will thus always correctly reflect the ownership of the idmapped upper or lower layer. All idmapping helpers are nops when no idmapped base layers are used. Cc: <linux-unionfs@vger.kernel.org> Tested-by: Giuseppe Scrivano <gscrivan@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: pass layer mnt to ovl_open_realfile()Amir Goldstein2022-04-281-9/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Ensure that ovl_open_realfile() takes the mount's idmapping into account. We add a new helper ovl_path_realdata() that can be used to easily retrieve the relevant path which we can pass down. This is needed to support idmapped base layers with overlay. Cc: <linux-unionfs@vger.kernel.org> Tested-by: Giuseppe Scrivano <gscrivan@redhat.com> Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | VFS: add FMODE_CAN_ODIRECT file flagNeilBrown2022-05-101-9/+4
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently various places test if direct IO is possible on a file by checking for the existence of the direct_IO address space operation. This is a poor choice, as the direct_IO operation may not be used - it is only used if the generic_file_*_iter functions are called for direct IO and some filesystems - particularly NFS - don't do this. Instead, introduce a new f_mode flag: FMODE_CAN_ODIRECT and change the various places to check this (avoiding pointer dereferences). do_dentry_open() will set this flag if ->direct_IO is present, so filesystems do not need to be changed. NFS *is* changed, to set the flag explicitly and discard the direct_IO entry in the address_space_operations for files. Other filesystems which currently use noop_direct_IO could usefully be changed to set this flag instead. Link: https://lkml.kernel.org/r/164859778128.29473.15189737957277399416.stgit@noble.brown Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.de> Tested-by: David Howells <dhowells@redhat.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Merge tag 'ovl-update-5.16' of ↵Linus Torvalds2021-11-091-2/+14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: - Fix a regression introduced in the last cycle - Fix a use-after-free in the AIO path - Fix a bogus warning reported by syzbot * tag 'ovl-update-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: fix filattr copy-up failure ovl: fix warning in ovl_create_real() ovl: fix use after free in struct ovl_aio_req
| * ovl: fix use after free in struct ovl_aio_reqyangerkun2021-10-291-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Example for triggering use after free in a overlay on ext4 setup: aio_read ovl_read_iter vfs_iter_read ext4_file_read_iter ext4_dio_read_iter iomap_dio_rw -> -EIOCBQUEUED /* * Here IO is completed in a separate thread, * ovl_aio_cleanup_handler() frees aio_req which has iocb embedded */ file_accessed(iocb->ki_filp); /**BOOM**/ Fix by introducing a refcount in ovl_aio_req similarly to aio_kiocb. This guarantees that iocb is only freed after vfs_read/write_iter() returns on underlying fs. Fixes: 2406a307ac7d ("ovl: implement async IO routines") Signed-off-by: yangerkun <yangerkun@huawei.com> Link: https://lore.kernel.org/r/20210930032228.3199690-3-yangerkun@huawei.com/ Cc: <stable@vger.kernel.org> # v5.6 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | fs: get rid of the res2 iocb->ki_complete argumentJens Axboe2021-10-251-2/+2
|/ | | | | | | | | | | The second argument was only used by the USB gadget code, yet everyone pays the overhead of passing a zero to be passed into aio, where it ends up being part of the aio res2 value. Now that everybody is passing in zero, kill off the extra argument. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* ovl: fix IOCB_DIRECT if underlying fs doesn't support direct IOMiklos Szeredi2021-09-281-1/+14
| | | | | | | | | | | | | | | Normally the check at open time suffices, but e.g loop device does set IOCB_DIRECT after doing its own checks (which are not sufficent for overlayfs). Make sure we don't call the underlying filesystem read/write method with the IOCB_DIRECT if it's not supported. Reported-by: Huang Jianan <huangjianan@oppo.com> Fixes: 16914e6fc7e1 ("ovl: add ovl_read_iter()") Cc: <stable@vger.kernel.org> # v4.19 Tested-by: Huang Jianan <huangjianan@oppo.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix deadlock in splice writeMiklos Szeredi2021-08-101-1/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's possibility of an ABBA deadlock in case of a splice write to an overlayfs file and a concurrent splice write to a corresponding real file. The call chain for splice to an overlay file: -> do_splice [takes sb_writers on overlay file] -> do_splice_from -> iter_file_splice_write [takes pipe->mutex] -> vfs_iter_write ... -> ovl_write_iter [takes sb_writers on real file] And the call chain for splice to a real file: -> do_splice [takes sb_writers on real file] -> do_splice_from -> iter_file_splice_write [takes pipe->mutex] Syzbot successfully bisected this to commit 82a763e61e2b ("ovl: simplify file splice"). Fix by reverting the write part of the above commit and by adding missing bits from ovl_write_iter() into ovl_splice_write(). Fixes: 82a763e61e2b ("ovl: simplify file splice") Reported-and-tested-by: syzbot+579885d1a9a833336209@syzkaller.appspotmail.com Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* Merge tag 'ovl-update-5.13' of ↵Linus Torvalds2021-05-011-0/+21
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs update from Miklos Szeredi: - Fix a regression introduced in 5.2 that resulted in valid overlayfs mounts being rejected with ELOOP (Too many levels of symbolic links) - Fix bugs found by various tools - Miscellaneous improvements and cleanups * tag 'ovl-update-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: add debug print to ovl_do_getxattr() ovl: invalidate readdir cache on changes to dir with origin ovl: allow upperdir inside lowerdir ovl: show "userxattr" in the mount data ovl: trivial typo fixes in the file inode.c ovl: fix misspellings using codespell tool ovl: do not copy attr several times ovl: remove ovl_map_dev_ino() return value ovl: fix error for ovl_fill_super() ovl: fix missing revert_creds() on error path ovl: fix leaked dentry ovl: restrict lower null uuid for "xino=auto" ovl: check that upperdir path is not on a read-only mount ovl: plumb through flush method
| * ovl: plumb through flush methodSargun Dhillon2021-04-121-0/+21
| | | | | | | | | | | | | | | | | | | | | | Filesystems can implement their own flush method that release resources, or manipulate caches. Currently if one of these filesystems is used with overlayfs, the flush method is not called. [Amir: fix fd leak in ovl_flush()] Signed-off-by: Sargun Dhillon <sargun@sargun.me> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | Merge branch 'miklos.fileattr' of ↵Linus Torvalds2021-04-271-110/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull fileattr conversion updates from Miklos Szeredi via Al Viro: "This splits the handling of FS_IOC_[GS]ETFLAGS from ->ioctl() into a separate method. The interface is reasonably uniform across the filesystems that support it and gives nice boilerplate removal" * 'miklos.fileattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (23 commits) ovl: remove unneeded ioctls fuse: convert to fileattr fuse: add internal open/release helpers fuse: unsigned open flags fuse: move ioctl to separate source file vfs: remove unused ioctl helpers ubifs: convert to fileattr reiserfs: convert to fileattr ocfs2: convert to fileattr nilfs2: convert to fileattr jfs: convert to fileattr hfsplus: convert to fileattr efivars: convert to fileattr xfs: convert to fileattr orangefs: convert to fileattr gfs2: convert to fileattr f2fs: convert to fileattr ext4: convert to fileattr ext2: convert to fileattr btrfs: convert to fileattr ...
| * | ovl: remove unneeded ioctlsMiklos Szeredi2021-04-121-110/+0
| |/ | | | | | | | | | | | | | | The FS_IOC_[GS]ETFLAGS/FS_IOC_FS[GS]ETXATTR ioctls are now handled via the fileattr api. The only unconverted filesystem remaining is CIFS and it is not allowed to be overlayed due to case insensitive filenames. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* / ovl: fix reference counting in ovl_mmap error pathChristian König2021-04-231-10/+1
|/ | | | | | | | | | | | | | | | | | mmap_region() now calls fput() on the vma->vm_file. Fix this by using vma_set_file() so it doesn't need to be handled manually here any more. Link: https://lkml.kernel.org/r/20210421132012.82354-2-christian.koenig@amd.com Fixes: 1527f926fd04 ("mm: mmap: fix fput in error path v2") Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Jan Harkes <jaharkes@cs.cmu.edu> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: <stable@vger.kernel.org> [5.11+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'idmapped-mounts-v5.12' of ↵Linus Torvalds2021-02-231-3/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull idmapped mounts from Christian Brauner: "This introduces idmapped mounts which has been in the making for some time. Simply put, different mounts can expose the same file or directory with different ownership. This initial implementation comes with ports for fat, ext4 and with Christoph's port for xfs with more filesystems being actively worked on by independent people and maintainers. Idmapping mounts handle a wide range of long standing use-cases. Here are just a few: - Idmapped mounts make it possible to easily share files between multiple users or multiple machines especially in complex scenarios. For example, idmapped mounts will be used in the implementation of portable home directories in systemd-homed.service(8) where they allow users to move their home directory to an external storage device and use it on multiple computers where they are assigned different uids and gids. This effectively makes it possible to assign random uids and gids at login time. - It is possible to share files from the host with unprivileged containers without having to change ownership permanently through chown(2). - It is possible to idmap a container's rootfs and without having to mangle every file. For example, Chromebooks use it to share the user's Download folder with their unprivileged containers in their Linux subsystem. - It is possible to share files between containers with non-overlapping idmappings. - Filesystem that lack a proper concept of ownership such as fat can use idmapped mounts to implement discretionary access (DAC) permission checking. - They allow users to efficiently changing ownership on a per-mount basis without having to (recursively) chown(2) all files. In contrast to chown (2) changing ownership of large sets of files is instantenous with idmapped mounts. This is especially useful when ownership of a whole root filesystem of a virtual machine or container is changed. With idmapped mounts a single syscall mount_setattr syscall will be sufficient to change the ownership of all files. - Idmapped mounts always take the current ownership into account as idmappings specify what a given uid or gid is supposed to be mapped to. This contrasts with the chown(2) syscall which cannot by itself take the current ownership of the files it changes into account. It simply changes the ownership to the specified uid and gid. This is especially problematic when recursively chown(2)ing a large set of files which is commong with the aforementioned portable home directory and container and vm scenario. - Idmapped mounts allow to change ownership locally, restricting it to specific mounts, and temporarily as the ownership changes only apply as long as the mount exists. Several userspace projects have either already put up patches and pull-requests for this feature or will do so should you decide to pull this: - systemd: In a wide variety of scenarios but especially right away in their implementation of portable home directories. https://systemd.io/HOME_DIRECTORY/ - container runtimes: containerd, runC, LXD:To share data between host and unprivileged containers, unprivileged and privileged containers, etc. The pull request for idmapped mounts support in containerd, the default Kubernetes runtime is already up for quite a while now: https://github.com/containerd/containerd/pull/4734 - The virtio-fs developers and several users have expressed interest in using this feature with virtual machines once virtio-fs is ported. - ChromeOS: Sharing host-directories with unprivileged containers. I've tightly synced with all those projects and all of those listed here have also expressed their need/desire for this feature on the mailing list. For more info on how people use this there's a bunch of talks about this too. Here's just two recent ones: https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf https://fosdem.org/2021/schedule/event/containers_idmap/ This comes with an extensive xfstests suite covering both ext4 and xfs: https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts It covers truncation, creation, opening, xattrs, vfscaps, setid execution, setgid inheritance and more both with idmapped and non-idmapped mounts. It already helped to discover an unrelated xfs setgid inheritance bug which has since been fixed in mainline. It will be sent for inclusion with the xfstests project should you decide to merge this. In order to support per-mount idmappings vfsmounts are marked with user namespaces. The idmapping of the user namespace will be used to map the ids of vfs objects when they are accessed through that mount. By default all vfsmounts are marked with the initial user namespace. The initial user namespace is used to indicate that a mount is not idmapped. All operations behave as before and this is verified in the testsuite. Based on prior discussions we want to attach the whole user namespace and not just a dedicated idmapping struct. This allows us to reuse all the helpers that already exist for dealing with idmappings instead of introducing a whole new range of helpers. In addition, if we decide in the future that we are confident enough to enable unprivileged users to setup idmapped mounts the permission checking can take into account whether the caller is privileged in the user namespace the mount is currently marked with. The user namespace the mount will be marked with can be specified by passing a file descriptor refering to the user namespace as an argument to the new mount_setattr() syscall together with the new MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern of extensibility. The following conditions must be met in order to create an idmapped mount: - The caller must currently have the CAP_SYS_ADMIN capability in the user namespace the underlying filesystem has been mounted in. - The underlying filesystem must support idmapped mounts. - The mount must not already be idmapped. This also implies that the idmapping of a mount cannot be altered once it has been idmapped. - The mount must be a detached/anonymous mount, i.e. it must have been created by calling open_tree() with the OPEN_TREE_CLONE flag and it must not already have been visible in the filesystem. The last two points guarantee easier semantics for userspace and the kernel and make the implementation significantly simpler. By default vfsmounts are marked with the initial user namespace and no behavioral or performance changes are observed. The manpage with a detailed description can be found here: https://git.kernel.org/brauner/man-pages/c/1d7b902e2875a1ff342e036a9f866a995640aea8 In order to support idmapped mounts, filesystems need to be changed and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The patches to convert individual filesystem are not very large or complicated overall as can be seen from the included fat, ext4, and xfs ports. Patches for other filesystems are actively worked on and will be sent out separately. The xfstestsuite can be used to verify that port has been done correctly. The mount_setattr() syscall is motivated independent of the idmapped mounts patches and it's been around since July 2019. One of the most valuable features of the new mount api is the ability to perform mounts based on file descriptors only. Together with the lookup restrictions available in the openat2() RESOLVE_* flag namespace which we added in v5.6 this is the first time we are close to hardened and race-free (e.g. symlinks) mounting and path resolution. While userspace has started porting to the new mount api to mount proper filesystems and create new bind-mounts it is currently not possible to change mount options of an already existing bind mount in the new mount api since the mount_setattr() syscall is missing. With the addition of the mount_setattr() syscall we remove this last restriction and userspace can now fully port to the new mount api, covering every use-case the old mount api could. We also add the crucial ability to recursively change mount options for a whole mount tree, both removing and adding mount options at the same time. This syscall has been requested multiple times by various people and projects. There is a simple tool available at https://github.com/brauner/mount-idmapped that allows to create idmapped mounts so people can play with this patch series. I'll add support for the regular mount binary should you decide to pull this in the following weeks: Here's an example to a simple idmapped mount of another user's home directory: u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt u1001@f2-vm:/$ ls -al /home/ubuntu/ total 28 drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 . drwxr-xr-x 4 root root 4096 Oct 28 04:00 .. -rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history -rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile -rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo u1001@f2-vm:/$ ls -al /mnt/ total 28 drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 . drwxr-xr-x 29 root root 4096 Oct 28 22:01 .. -rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history -rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile -rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo u1001@f2-vm:/$ touch /mnt/my-file u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file u1001@f2-vm:/$ ls -al /mnt/my-file -rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file u1001@f2-vm:/$ ls -al /home/ubuntu/my-file -rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file u1001@f2-vm:/$ getfacl /mnt/my-file getfacl: Removing leading '/' from absolute path names # file: mnt/my-file # owner: u1001 # group: u1001 user::rw- user:u1001:rwx group::rw- mask::rwx other::r-- u1001@f2-vm:/$ getfacl /home/ubuntu/my-file getfacl: Removing leading '/' from absolute path names # file: home/ubuntu/my-file # owner: ubuntu # group: ubuntu user::rw- user:ubuntu:rwx group::rw- mask::rwx other::r--" * tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits) xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl xfs: support idmapped mounts ext4: support idmapped mounts fat: handle idmapped mounts tests: add mount_setattr() selftests fs: introduce MOUNT_ATTR_IDMAP fs: add mount_setattr() fs: add attr_flags_to_mnt_flags helper fs: split out functions to hold writers namespace: only take read lock in do_reconfigure_mnt() mount: make {lock,unlock}_mount_hash() static namespace: take lock_mount_hash() directly when changing flags nfs: do not export idmapped mounts overlayfs: do not mount on top of idmapped mounts ecryptfs: do not mount on top of idmapped mounts ima: handle idmapped mounts apparmor: handle idmapped mounts fs: make helpers idmap mount aware exec: handle idmapped mounts would_dump: handle idmapped mounts ...
| * inode: make init and permission helpers idmapped mount awareChristian Brauner2021-01-241-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The inode_owner_or_capable() helper determines whether the caller is the owner of the inode or is capable with respect to that inode. Allow it to handle idmapped mounts. If the inode is accessed through an idmapped mount it according to the mount's user namespace. Afterwards the checks are identical to non-idmapped mounts. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Similarly, allow the inode_init_owner() helper to handle idmapped mounts. It initializes a new inode on idmapped mounts by mapping the fsuid and fsgid of the caller from the mount's user namespace. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-7-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
| * namei: make permission helpers idmapped mount awareChristian Brauner2021-01-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The two helpers inode_permission() and generic_permission() are used by the vfs to perform basic permission checking by verifying that the caller is privileged over an inode. In order to handle idmapped mounts we extend the two helpers with an additional user namespace argument. On idmapped mounts the two helpers will make sure to map the inode according to the mount's user namespace and then peform identical permission checks to inode_permission() and generic_permission(). If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-6-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
* | ovl: implement volatile-specific fsync error behaviourSargun Dhillon2021-01-281-2/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Overlayfs's volatile option allows the user to bypass all forced sync calls to the upperdir filesystem. This comes at the cost of safety. We can never ensure that the user's data is intact, but we can make a best effort to expose whether or not the data is likely to be in a bad state. The best way to handle this in the time being is that if an overlayfs's upperdir experiences an error after a volatile mount occurs, that error will be returned on fsync, fdatasync, sync, and syncfs. This is contradictory to the traditional behaviour of VFS which fails the call once, and only raises an error if a subsequent fsync error has occurred, and been raised by the filesystem. One awkward aspect of the patch is that we have to manually set the superblock's errseq_t after the sync_fs callback as opposed to just returning an error from syncfs. This is because the call chain looks something like this: sys_syncfs -> sync_filesystem -> __sync_filesystem -> /* The return value is ignored here sb->s_op->sync_fs(sb) _sync_blockdev /* Where the VFS fetches the error to raise to userspace */ errseq_check_and_advance Because of this we call errseq_set every time the sync_fs callback occurs. Due to the nature of this seen / unseen dichotomy, if the upperdir is an inconsistent state at the initial mount time, overlayfs will refuse to mount, as overlayfs cannot get a snapshot of the upperdir's errseq that will increment on error until the user calls syncfs. Signed-off-by: Sargun Dhillon <sargun@sargun.me> Suggested-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Fixes: c86243b090bc ("ovl: provide a mount option "volatile"") Cc: stable@vger.kernel.org Reviewed-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: do not fail because of O_NOATIMEMiklos Szeredi2020-12-141-8/+3
| | | | | | | | | | In case the file cannot be opened with O_NOATIME because of lack of capabilities, then clear O_NOATIME instead of failing. Remove WARN_ON(), since it would now trigger if O_NOATIME was cleared. Noticed by Amir Goldstein. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: simplify file spliceMiklos Szeredi2020-12-141-44/+2
| | | | | | | | | | | | | | | generic_file_splice_read() and iter_file_splice_write() will call back into f_op->iter_read() and f_op->iter_write() respectively. These already do the real file lookup and cred override. So the code in ovl_splice_read() and ovl_splice_write() is redundant. In addition the ovl_file_accessed() call in ovl_splice_write() is incorrect, though probably harmless. Fix by calling generic_file_splice_read() and iter_file_splice_write() directly. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: make ioctl() safeMiklos Szeredi2020-12-141-71/+16
| | | | | | | | | | | | | | | | | | | | | | | ovl_ioctl_set_flags() does a capability check using flags, but then the real ioctl double-fetches flags and uses potentially different value. The "Check the capability before cred override" comment misleading: user can skip this check by presenting benign flags first and then overwriting them to non-benign flags. Just remove the cred override for now, hoping this doesn't cause a regression. The proper solution is to create a new setxflags i_op (patches are in the works). Xfstests don't show a regression. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Fixes: dab5ca8fd9dd ("ovl: add lsattr/chattr support") Cc: <stable@vger.kernel.org> # v4.19
* ovl: use generic vfs_ioc_setflags_prepare() helperAmir Goldstein2020-10-061-32/+30
| | | | | | | | | | | | | Canonalize to ioctl FS_* flags instead of inode S_* flags. Note that we do not call the helper vfs_ioc_fssetxattr_check() for FS_IOC_FSSETXATTR ioctl. The reason is that underlying filesystem will perform all the checks. We only need to perform the capability check before overriding credentials. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: support [S|G]ETFLAGS and FS[S|G]ETXATTR ioctls for directoriesAmir Goldstein2020-10-061-3/+13
| | | | | | | | | | | | | | | | | [S|G]ETFLAGS and FS[S|G]ETXATTR ioctls are applicable to both files and directories, so add ioctl operations to dir as well. We teach ovl_real_fdget() to get the realfile of directories which use a different type of file->private_data. Ifdef away compat ioctl implementation to conform to standard practice. With this change, xfstest generic/079 which tests these ioctls on files and directories passes. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: provide a mount option "volatile"Vivek Goyal2020-09-021-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Container folks are complaining that dnf/yum issues too many sync while installing packages and this slows down the image build. Build requirement is such that they don't care if a node goes down while build was still going on. In that case, they will simply throw away unfinished layer and start new build. So they don't care about syncing intermediate state to the disk and hence don't want to pay the price associated with sync. So they are asking for mount options where they can disable sync on overlay mount point. They primarily seem to have two use cases. - For building images, they will mount overlay with nosync and then sync upper layer after unmounting overlay and reuse upper as lower for next layer. - For running containers, they don't seem to care about syncing upper layer because if node goes down, they will simply throw away upper layer and create a fresh one. So this patch provides a mount option "volatile" which disables all forms of sync. Now it is caller's responsibility to throw away upper if system crashes or shuts down and start fresh. With "volatile", I am seeing roughly 20% speed up in my VM where I am just installing emacs in an image. Installation time drops from 31 seconds to 25 seconds when nosync option is used. This is for the case of building on top of an image where all packages are already cached. That way I take out the network operations latency out of the measurement. Giuseppe is also looking to cut down on number of iops done on the disk. He is complaining that often in cloud their VMs are throttled if they cross the limit. This option can help them where they reduce number of iops (by cutting down on frequent sync and writebacks). Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix unneeded call to ovl_change_flags()Amir Goldstein2020-07-161-4/+6
| | | | | | | | | | The check if user has changed the overlay file was wrong, causing unneeded call to ovl_change_flags() including taking f_lock on every file access. Fixes: d989903058a8 ("ovl: do not generate duplicate fsnotify events for "fake" path") Cc: <stable@vger.kernel.org> # v4.19+ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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