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linux/fs/backing-file.c

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fs: prepare for stackable filesystems backing file helpers In preparation for factoring out some backing file io helpers from overlayfs, move backing_file_open() into a new file fs/backing-file.c and header. Add a MAINTAINERS entry for stackable filesystems and add a Kconfig FS_STACK which stackable filesystems need to select. For now, the backing_file struct, the backing_file alloc/free functions and the backing_file_real_path() accessor remain internal to file_table.c. We may change that in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-02 17:19:46 +03:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00
fs: prepare for stackable filesystems backing file helpers In preparation for factoring out some backing file io helpers from overlayfs, move backing_file_open() into a new file fs/backing-file.c and header. Add a MAINTAINERS entry for stackable filesystems and add a Kconfig FS_STACK which stackable filesystems need to select. For now, the backing_file struct, the backing_file alloc/free functions and the backing_file_real_path() accessor remain internal to file_table.c. We may change that in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-02 17:19:46 +03:00
fs: factor out backing_file_splice_{read,write}() helpers There is not much in those helpers, but it makes sense to have them logically next to the backing_file_{read,write}_iter() helpers as they may grow more common logic in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:13:12 +03:00
fs: factor out backing_file_mmap() helper Assert that the file object is allocated in a backing_file container so that file_user_path() could be used to display the user path and not the backing file's path in /proc/<pid>/maps. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:49:37 +03:00
lsm: add backing_file LSM hooks Stacked filesystems such as overlayfs do not currently provide the necessary mechanisms for LSMs to properly enforce access controls on the mmap() and mprotect() operations. In order to resolve this gap, a LSM security blob is being added to the backing_file struct and the following new LSM hooks are being created: security_backing_file_alloc() security_backing_file_free() security_mmap_backing_file() The first two hooks are to manage the lifecycle of the LSM security blob in the backing_file struct, while the third provides a new mmap() access control point for the underlying backing file. It is also expected that LSMs will likely want to update their security_file_mprotect() callback to address issues with their mprotect() controls, but that does not require a change to the security_file_mprotect() LSM hook. There are a three other small changes to support these new LSM hooks: * Pass the user file associated with a backing file down to alloc_empty_backing_file() so it can be included in the security_backing_file_alloc() hook. * Add getter and setter functions for the backing_file struct LSM blob as the backing_file struct remains private to fs/file_table.c. * Constify the file struct field in the LSM common_audit_data struct to better support LSMs that need to pass a const file struct pointer into the common LSM audit code. Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL() and supplying a fixup. Cc: stable@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-unionfs@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-12-19 13:18:22 -05:00
fs: prepare for stackable filesystems backing file helpers In preparation for factoring out some backing file io helpers from overlayfs, move backing_file_open() into a new file fs/backing-file.c and header. Add a MAINTAINERS entry for stackable filesystems and add a Kconfig FS_STACK which stackable filesystems need to select. For now, the backing_file struct, the backing_file alloc/free functions and the backing_file_real_path() accessor remain internal to file_table.c. We may change that in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-02 17:19:46 +03:00
lsm: add backing_file LSM hooks Stacked filesystems such as overlayfs do not currently provide the necessary mechanisms for LSMs to properly enforce access controls on the mmap() and mprotect() operations. In order to resolve this gap, a LSM security blob is being added to the backing_file struct and the following new LSM hooks are being created: security_backing_file_alloc() security_backing_file_free() security_mmap_backing_file() The first two hooks are to manage the lifecycle of the LSM security blob in the backing_file struct, while the third provides a new mmap() access control point for the underlying backing file. It is also expected that LSMs will likely want to update their security_file_mprotect() callback to address issues with their mprotect() controls, but that does not require a change to the security_file_mprotect() LSM hook. There are a three other small changes to support these new LSM hooks: * Pass the user file associated with a backing file down to alloc_empty_backing_file() so it can be included in the security_backing_file_alloc() hook. * Add getter and setter functions for the backing_file struct LSM blob as the backing_file struct remains private to fs/file_table.c. * Constify the file struct field in the LSM common_audit_data struct to better support LSMs that need to pass a const file struct pointer into the common LSM audit code. Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL() and supplying a fixup. Cc: stable@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-unionfs@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-12-19 13:18:22 -05:00
fs: prepare for stackable filesystems backing file helpers In preparation for factoring out some backing file io helpers from overlayfs, move backing_file_open() into a new file fs/backing-file.c and header. Add a MAINTAINERS entry for stackable filesystems and add a Kconfig FS_STACK which stackable filesystems need to select. For now, the backing_file struct, the backing_file alloc/free functions and the backing_file_real_path() accessor remain internal to file_table.c. We may change that in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-02 17:19:46 +03:00
lsm: add backing_file LSM hooks Stacked filesystems such as overlayfs do not currently provide the necessary mechanisms for LSMs to properly enforce access controls on the mmap() and mprotect() operations. In order to resolve this gap, a LSM security blob is being added to the backing_file struct and the following new LSM hooks are being created: security_backing_file_alloc() security_backing_file_free() security_mmap_backing_file() The first two hooks are to manage the lifecycle of the LSM security blob in the backing_file struct, while the third provides a new mmap() access control point for the underlying backing file. It is also expected that LSMs will likely want to update their security_file_mprotect() callback to address issues with their mprotect() controls, but that does not require a change to the security_file_mprotect() LSM hook. There are a three other small changes to support these new LSM hooks: * Pass the user file associated with a backing file down to alloc_empty_backing_file() so it can be included in the security_backing_file_alloc() hook. * Add getter and setter functions for the backing_file struct LSM blob as the backing_file struct remains private to fs/file_table.c. * Constify the file struct field in the LSM common_audit_data struct to better support LSMs that need to pass a const file struct pointer into the common LSM audit code. Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL() and supplying a fixup. Cc: stable@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-unionfs@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-12-19 13:18:22 -05:00
fs: prepare for stackable filesystems backing file helpers In preparation for factoring out some backing file io helpers from overlayfs, move backing_file_open() into a new file fs/backing-file.c and header. Add a MAINTAINERS entry for stackable filesystems and add a Kconfig FS_STACK which stackable filesystems need to select. For now, the backing_file struct, the backing_file alloc/free functions and the backing_file_real_path() accessor remain internal to file_table.c. We may change that in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-02 17:19:46 +03:00
lsm: add backing_file LSM hooks Stacked filesystems such as overlayfs do not currently provide the necessary mechanisms for LSMs to properly enforce access controls on the mmap() and mprotect() operations. In order to resolve this gap, a LSM security blob is being added to the backing_file struct and the following new LSM hooks are being created: security_backing_file_alloc() security_backing_file_free() security_mmap_backing_file() The first two hooks are to manage the lifecycle of the LSM security blob in the backing_file struct, while the third provides a new mmap() access control point for the underlying backing file. It is also expected that LSMs will likely want to update their security_file_mprotect() callback to address issues with their mprotect() controls, but that does not require a change to the security_file_mprotect() LSM hook. There are a three other small changes to support these new LSM hooks: * Pass the user file associated with a backing file down to alloc_empty_backing_file() so it can be included in the security_backing_file_alloc() hook. * Add getter and setter functions for the backing_file struct LSM blob as the backing_file struct remains private to fs/file_table.c. * Constify the file struct field in the LSM common_audit_data struct to better support LSMs that need to pass a const file struct pointer into the common LSM audit code. Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL() and supplying a fixup. Cc: stable@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-unionfs@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-12-19 13:18:22 -05:00
fs: prepare for stackable filesystems backing file helpers In preparation for factoring out some backing file io helpers from overlayfs, move backing_file_open() into a new file fs/backing-file.c and header. Add a MAINTAINERS entry for stackable filesystems and add a Kconfig FS_STACK which stackable filesystems need to select. For now, the backing_file struct, the backing_file alloc/free functions and the backing_file_real_path() accessor remain internal to file_table.c. We may change that in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-02 17:19:46 +03:00
fs: constify file ptr in backing_file accessor helpers Add internal helper backing_file_set_user_path() for the only two cases that need to modify backing_file fields. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/20250607115304.2521155-2-amir73il@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-06-07 13:53:03 +02:00
fs: prepare for stackable filesystems backing file helpers In preparation for factoring out some backing file io helpers from overlayfs, move backing_file_open() into a new file fs/backing-file.c and header. Add a MAINTAINERS entry for stackable filesystems and add a Kconfig FS_STACK which stackable filesystems need to select. For now, the backing_file struct, the backing_file alloc/free functions and the backing_file_real_path() accessor remain internal to file_table.c. We may change that in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-02 17:19:46 +03:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00
lsm: add backing_file LSM hooks Stacked filesystems such as overlayfs do not currently provide the necessary mechanisms for LSMs to properly enforce access controls on the mmap() and mprotect() operations. In order to resolve this gap, a LSM security blob is being added to the backing_file struct and the following new LSM hooks are being created: security_backing_file_alloc() security_backing_file_free() security_mmap_backing_file() The first two hooks are to manage the lifecycle of the LSM security blob in the backing_file struct, while the third provides a new mmap() access control point for the underlying backing file. It is also expected that LSMs will likely want to update their security_file_mprotect() callback to address issues with their mprotect() controls, but that does not require a change to the security_file_mprotect() LSM hook. There are a three other small changes to support these new LSM hooks: * Pass the user file associated with a backing file down to alloc_empty_backing_file() so it can be included in the security_backing_file_alloc() hook. * Add getter and setter functions for the backing_file struct LSM blob as the backing_file struct remains private to fs/file_table.c. * Constify the file struct field in the LSM common_audit_data struct to better support LSMs that need to pass a const file struct pointer into the common LSM audit code. Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL() and supplying a fixup. Cc: stable@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-unionfs@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-12-19 13:18:22 -05:00
ovl: implement tmpfile Combine inode creation with opening a file. There are six separate objects that are being set up: the backing inode, dentry and file, and the overlay inode, dentry and file. Cleanup in case of an error is a bit of a challenge and is difficult to test, so careful review is needed. All tmpfile testcases except generic/509 now run/pass, and no regressions are observed with full xfstests. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com>
2024-05-02 20:35:57 +02:00
lsm: add backing_file LSM hooks Stacked filesystems such as overlayfs do not currently provide the necessary mechanisms for LSMs to properly enforce access controls on the mmap() and mprotect() operations. In order to resolve this gap, a LSM security blob is being added to the backing_file struct and the following new LSM hooks are being created: security_backing_file_alloc() security_backing_file_free() security_mmap_backing_file() The first two hooks are to manage the lifecycle of the LSM security blob in the backing_file struct, while the third provides a new mmap() access control point for the underlying backing file. It is also expected that LSMs will likely want to update their security_file_mprotect() callback to address issues with their mprotect() controls, but that does not require a change to the security_file_mprotect() LSM hook. There are a three other small changes to support these new LSM hooks: * Pass the user file associated with a backing file down to alloc_empty_backing_file() so it can be included in the security_backing_file_alloc() hook. * Add getter and setter functions for the backing_file struct LSM blob as the backing_file struct remains private to fs/file_table.c. * Constify the file struct field in the LSM common_audit_data struct to better support LSMs that need to pass a const file struct pointer into the common LSM audit code. Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL() and supplying a fixup. Cc: stable@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-unionfs@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-12-19 13:18:22 -05:00
ovl: implement tmpfile Combine inode creation with opening a file. There are six separate objects that are being set up: the backing inode, dentry and file, and the overlay inode, dentry and file. Cleanup in case of an error is a bit of a challenge and is difficult to test, so careful review is needed. All tmpfile testcases except generic/509 now run/pass, and no regressions are observed with full xfstests. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com>
2024-05-02 20:35:57 +02:00
lsm: add backing_file LSM hooks Stacked filesystems such as overlayfs do not currently provide the necessary mechanisms for LSMs to properly enforce access controls on the mmap() and mprotect() operations. In order to resolve this gap, a LSM security blob is being added to the backing_file struct and the following new LSM hooks are being created: security_backing_file_alloc() security_backing_file_free() security_mmap_backing_file() The first two hooks are to manage the lifecycle of the LSM security blob in the backing_file struct, while the third provides a new mmap() access control point for the underlying backing file. It is also expected that LSMs will likely want to update their security_file_mprotect() callback to address issues with their mprotect() controls, but that does not require a change to the security_file_mprotect() LSM hook. There are a three other small changes to support these new LSM hooks: * Pass the user file associated with a backing file down to alloc_empty_backing_file() so it can be included in the security_backing_file_alloc() hook. * Add getter and setter functions for the backing_file struct LSM blob as the backing_file struct remains private to fs/file_table.c. * Constify the file struct field in the LSM common_audit_data struct to better support LSMs that need to pass a const file struct pointer into the common LSM audit code. Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL() and supplying a fixup. Cc: stable@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-unionfs@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-12-19 13:18:22 -05:00
ovl: implement tmpfile Combine inode creation with opening a file. There are six separate objects that are being set up: the backing inode, dentry and file, and the overlay inode, dentry and file. Cleanup in case of an error is a bit of a challenge and is difficult to test, so careful review is needed. All tmpfile testcases except generic/509 now run/pass, and no regressions are observed with full xfstests. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com>
2024-05-02 20:35:57 +02:00
fs: constify file ptr in backing_file accessor helpers Add internal helper backing_file_set_user_path() for the only two cases that need to modify backing_file fields. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/20250607115304.2521155-2-amir73il@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-06-07 13:53:03 +02:00
ovl: implement tmpfile Combine inode creation with opening a file. There are six separate objects that are being set up: the backing inode, dentry and file, and the overlay inode, dentry and file. Cleanup in case of an error is a bit of a challenge and is difficult to test, so careful review is needed. All tmpfile testcases except generic/509 now run/pass, and no regressions are observed with full xfstests. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com>
2024-05-02 20:35:57 +02:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00
backing-file: clean up the API - Pass iocb to ctx->end_write() instead of file + pos - Get rid of ctx->user_file, which is redundant most of the time - Instead pass iocb to backing_file_splice_read and backing_file_splice_write Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2024-10-21 12:33:38 +02:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00
backing-file: clean up the API - Pass iocb to ctx->end_write() instead of file + pos - Get rid of ctx->user_file, which is redundant most of the time - Instead pass iocb to backing_file_splice_read and backing_file_splice_write Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2024-10-21 12:33:38 +02:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00
backing-file: use credential guards for reads Use credential guards for scoped credential override with automatic restoration on scope exit. Link: https://patch.msgid.link/20251103-work-creds-guards-simple-v1-3-a3e156839e7f@kernel.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-03 12:26:51 +01:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00
backing-file: use credential guards for reads Use credential guards for scoped credential override with automatic restoration on scope exit. Link: https://patch.msgid.link/20251103-work-creds-guards-simple-v1-3-a3e156839e7f@kernel.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-03 12:26:51 +01:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00
backing-file: clean up the API - Pass iocb to ctx->end_write() instead of file + pos - Get rid of ctx->user_file, which is redundant most of the time - Instead pass iocb to backing_file_splice_read and backing_file_splice_write Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2024-10-21 12:33:38 +02:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00
backing-file: use credential guards for writes Use credential guards for scoped credential override with automatic restoration on scope exit. Link: https://patch.msgid.link/20251103-work-creds-guards-simple-v1-4-a3e156839e7f@kernel.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-03 12:26:52 +01:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00
backing-file: clean up the API - Pass iocb to ctx->end_write() instead of file + pos - Get rid of ctx->user_file, which is redundant most of the time - Instead pass iocb to backing_file_splice_read and backing_file_splice_write Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2024-10-21 12:33:38 +02:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00
backing-file: use credential guards for writes Use credential guards for scoped credential override with automatic restoration on scope exit. Link: https://patch.msgid.link/20251103-work-creds-guards-simple-v1-4-a3e156839e7f@kernel.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-03 12:26:52 +01:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00
backing-file: clean up the API - Pass iocb to ctx->end_write() instead of file + pos - Get rid of ctx->user_file, which is redundant most of the time - Instead pass iocb to backing_file_splice_read and backing_file_splice_write Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2024-10-21 12:33:38 +02:00
fs: factor out backing_file_splice_{read,write}() helpers There is not much in those helpers, but it makes sense to have them logically next to the backing_file_{read,write}_iter() helpers as they may grow more common logic in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:13:12 +03:00
backing-file: use credential guards for splice read Use credential guards for scoped credential override with automatic restoration on scope exit. Link: https://patch.msgid.link/20251103-work-creds-guards-simple-v1-5-a3e156839e7f@kernel.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-03 12:26:53 +01:00
fs: factor out backing_file_splice_{read,write}() helpers There is not much in those helpers, but it makes sense to have them logically next to the backing_file_{read,write}_iter() helpers as they may grow more common logic in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:13:12 +03:00
backing-file: clean up the API - Pass iocb to ctx->end_write() instead of file + pos - Get rid of ctx->user_file, which is redundant most of the time - Instead pass iocb to backing_file_splice_read and backing_file_splice_write Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2024-10-21 12:33:38 +02:00
fs: factor out backing_file_splice_{read,write}() helpers There is not much in those helpers, but it makes sense to have them logically next to the backing_file_{read,write}_iter() helpers as they may grow more common logic in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:13:12 +03:00
backing-file: clean up the API - Pass iocb to ctx->end_write() instead of file + pos - Get rid of ctx->user_file, which is redundant most of the time - Instead pass iocb to backing_file_splice_read and backing_file_splice_write Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2024-10-21 12:33:38 +02:00
fs: factor out backing_file_splice_{read,write}() helpers There is not much in those helpers, but it makes sense to have them logically next to the backing_file_{read,write}_iter() helpers as they may grow more common logic in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:13:12 +03:00
backing-file: convert to using fops->splice_write Filesystems may define their own splice write. Therefore, use the file fops instead of invoking iter_file_splice_write() directly. Signed-off-by: Ed Tsai <ed.tsai@mediatek.com> Link: https://lore.kernel.org/r/20240708072208.25244-1-ed.tsai@mediatek.com Fixes: 5ca73468612d ("fuse: implement splice read/write passthrough") Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-07-08 15:22:06 +08:00
backing-file: clean up the API - Pass iocb to ctx->end_write() instead of file + pos - Get rid of ctx->user_file, which is redundant most of the time - Instead pass iocb to backing_file_splice_read and backing_file_splice_write Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2024-10-21 12:33:38 +02:00
fs: factor out backing_file_splice_{read,write}() helpers There is not much in those helpers, but it makes sense to have them logically next to the backing_file_{read,write}_iter() helpers as they may grow more common logic in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:13:12 +03:00
backing-file: use credential guards for splice write Use credential guards for scoped credential override with automatic restoration on scope exit. Link: https://patch.msgid.link/20251103-work-creds-guards-simple-v1-6-a3e156839e7f@kernel.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-03 12:26:54 +01:00
fs: factor out backing_file_splice_{read,write}() helpers There is not much in those helpers, but it makes sense to have them logically next to the backing_file_{read,write}_iter() helpers as they may grow more common logic in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:13:12 +03:00
backing-file: clean up the API - Pass iocb to ctx->end_write() instead of file + pos - Get rid of ctx->user_file, which is redundant most of the time - Instead pass iocb to backing_file_splice_read and backing_file_splice_write Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2024-10-21 12:33:38 +02:00
fs: factor out backing_file_splice_{read,write}() helpers There is not much in those helpers, but it makes sense to have them logically next to the backing_file_{read,write}_iter() helpers as they may grow more common logic in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:13:12 +03:00
fs: factor out backing_file_mmap() helper Assert that the file object is allocated in a backing_file container so that file_user_path() could be used to display the user path and not the backing file's path in /proc/<pid>/maps. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:49:37 +03:00
fs/backing_file: fix wrong argument in callback Commit 48b50624aec4 ("backing-file: clean up the API") unintentionally changed the argument in the ->accessed() callback from the user file to the backing file. Fixes: 48b50624aec4 ("backing-file: clean up the API") Reported-by: syzbot+8d1206605b05ca9a0e6a@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-unionfs/67447b3c.050a0220.1cc393.0085.GAE@google.com/ Tested-by: syzbot+8d1206605b05ca9a0e6a@syzkaller.appspotmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20241126145342.364869-1-amir73il@gmail.com Acked-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-11-26 15:53:42 +01:00
fs: factor out backing_file_mmap() helper Assert that the file object is allocated in a backing_file container so that file_user_path() could be used to display the user path and not the backing file's path in /proc/<pid>/maps. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:49:37 +03:00
backing-file: clean up the API - Pass iocb to ctx->end_write() instead of file + pos - Get rid of ctx->user_file, which is redundant most of the time - Instead pass iocb to backing_file_splice_read and backing_file_splice_write Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2024-10-21 12:33:38 +02:00
fs: factor out backing_file_mmap() helper Assert that the file object is allocated in a backing_file container so that file_user_path() could be used to display the user path and not the backing file's path in /proc/<pid>/maps. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:49:37 +03:00
fs: consistently use can_mmap_file() helper 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(). Additionally, commit bb666b7c2707 ("mm: add mmap_prepare() compatibility layer for nested file systems") permits the use of the .mmap_prepare() hook even in nested filesystems like overlayfs. There are a number of places where we check only for f_op->mmap - this is incorrect now mmap_prepare exists, so update all of these to use the general helper can_mmap_file(). Most notably, this updates the elf logic to allow for the ability to execute binaries on filesystems which have the .mmap_prepare hook, but additionally we update nested filesystems. Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Link: https://lore.kernel.org/b68145b609532e62bab603dd9686faa6562046ec.1750099179.git.lorenzo.stoakes@oracle.com Acked-by: Kees Cook <kees@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-06-16 20:33:22 +01:00
fs: factor out backing_file_mmap() helper Assert that the file object is allocated in a backing_file container so that file_user_path() could be used to display the user path and not the backing file's path in /proc/<pid>/maps. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:49:37 +03:00
lsm: add backing_file LSM hooks Stacked filesystems such as overlayfs do not currently provide the necessary mechanisms for LSMs to properly enforce access controls on the mmap() and mprotect() operations. In order to resolve this gap, a LSM security blob is being added to the backing_file struct and the following new LSM hooks are being created: security_backing_file_alloc() security_backing_file_free() security_mmap_backing_file() The first two hooks are to manage the lifecycle of the LSM security blob in the backing_file struct, while the third provides a new mmap() access control point for the underlying backing file. It is also expected that LSMs will likely want to update their security_file_mprotect() callback to address issues with their mprotect() controls, but that does not require a change to the security_file_mprotect() LSM hook. There are a three other small changes to support these new LSM hooks: * Pass the user file associated with a backing file down to alloc_empty_backing_file() so it can be included in the security_backing_file_alloc() hook. * Add getter and setter functions for the backing_file struct LSM blob as the backing_file struct remains private to fs/file_table.c. * Constify the file struct field in the LSM common_audit_data struct to better support LSMs that need to pass a const file struct pointer into the common LSM audit code. Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL() and supplying a fixup. Cc: stable@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-unionfs@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-12-19 13:18:22 -05:00
backing-file: use credential guards for mmap Use credential guards for scoped credential override with automatic restoration on scope exit. Link: https://patch.msgid.link/20251103-work-creds-guards-simple-v1-7-a3e156839e7f@kernel.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-03 12:26:55 +01:00
lsm: add backing_file LSM hooks Stacked filesystems such as overlayfs do not currently provide the necessary mechanisms for LSMs to properly enforce access controls on the mmap() and mprotect() operations. In order to resolve this gap, a LSM security blob is being added to the backing_file struct and the following new LSM hooks are being created: security_backing_file_alloc() security_backing_file_free() security_mmap_backing_file() The first two hooks are to manage the lifecycle of the LSM security blob in the backing_file struct, while the third provides a new mmap() access control point for the underlying backing file. It is also expected that LSMs will likely want to update their security_file_mprotect() callback to address issues with their mprotect() controls, but that does not require a change to the security_file_mprotect() LSM hook. There are a three other small changes to support these new LSM hooks: * Pass the user file associated with a backing file down to alloc_empty_backing_file() so it can be included in the security_backing_file_alloc() hook. * Add getter and setter functions for the backing_file struct LSM blob as the backing_file struct remains private to fs/file_table.c. * Constify the file struct field in the LSM common_audit_data struct to better support LSMs that need to pass a const file struct pointer into the common LSM audit code. Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL() and supplying a fixup. Cc: stable@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-unionfs@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-12-19 13:18:22 -05:00
fs: factor out backing_file_mmap() helper Assert that the file object is allocated in a backing_file container so that file_user_path() could be used to display the user path and not the backing file's path in /proc/<pid>/maps. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:49:37 +03:00
fs/backing_file: fix wrong argument in callback Commit 48b50624aec4 ("backing-file: clean up the API") unintentionally changed the argument in the ->accessed() callback from the user file to the backing file. Fixes: 48b50624aec4 ("backing-file: clean up the API") Reported-by: syzbot+8d1206605b05ca9a0e6a@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-unionfs/67447b3c.050a0220.1cc393.0085.GAE@google.com/ Tested-by: syzbot+8d1206605b05ca9a0e6a@syzkaller.appspotmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20241126145342.364869-1-amir73il@gmail.com Acked-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-11-26 15:53:42 +01:00
fs: factor out backing_file_mmap() helper Assert that the file object is allocated in a backing_file container so that file_user_path() could be used to display the user path and not the backing file's path in /proc/<pid>/maps. Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-10-13 12:49:37 +03:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00
fs: Use KMEM_CACHE instead of kmem_cache_create commit 0a31bd5f2bbb ("KMEM_CACHE(): simplify slab cache creation") introduces a new macro. Use the new KMEM_CACHE() macro instead of direct kmem_cache_create to simplify the creation of SLAB caches. Signed-off-by: Kunwu Chan <chentao@kylinos.cn> Link: https://lore.kernel.org/r/20240131070941.135178-1-chentao@kylinos.cn Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-01-31 15:09:41 +08:00
fs: factor out backing_file_{read,write}_iter() helpers Overlayfs submits files io to backing files on other filesystems. Factor out some common helpers to perform io to backing files, into fs/backing-file.c. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2023-11-22 17:48:52 +02:00