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path: root/fs/exfat/exfat_fs.h
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2023-08-10exfat: don't RCU-free the sbiChristoph Hellwig
There are no RCU critical sections for accessing any information in the sbi, so drop the call_rcu indirection for freeing the sbi. Signed-off-by: Christoph Hellwig <hch@lst.de> Message-Id: <20230809220545.1308228-10-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-03-01Merge tag 'exfat-for-6.3-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat Pull exfat updates from Namjae Jeon: - Handle vendor extension and allocation entries as unrecognized benign secondary entries - Fix wrong ->i_blocks on devices with non-512 byte sector - Add the check to avoid returning -EIO from exfat_readdir() at current position exceeding the directory size - Fix a bug that reach the end of the directory stream at a position not aligned with the dentry size - Redefine DIR_DELETED as 0xFFFFFFF7, the bad cluster number - Two cleanup fixes and fix cluster leakage in error handling * tag 'exfat-for-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat: exfat: fix the newly allocated clusters are not freed in error handling exfat: don't print error log in normal case exfat: remove unneeded code from exfat_alloc_cluster() exfat: handle unreconized benign secondary entries exfat: fix inode->i_blocks for non-512 byte sector size device exfat: redefine DIR_DELETED as the bad cluster number exfat: fix reporting fs error when reading dir beyond EOF exfat: fix unexpected EOF while reading dir
2023-02-27exfat: handle unreconized benign secondary entriesNamjae Jeon
Sony PXW-Z280 camera add vendor allocation entries to directory of pictures. Currently, linux exfat does not support it and the file is not visible. This patch handle vendor extension and allocation entries as unreconized benign secondary entries. As described in the specification, it is recognized but ignored, and when deleting directory entry set, the associated clusters allocation are removed as well as benign secondary directory entries. Reported-by: Barócsi Dénes <admin@tveger.hu> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2023-02-27exfat: redefine DIR_DELETED as the bad cluster numberSungjong Seo
When a file or a directory is deleted, the hint for the cluster of its parent directory in its in-memory inode is set as DIR_DELETED. Therefore, DIR_DELETED must be one of invalid cluster numbers. According to the exFAT specification, a volume can have at most 2^32-11 clusters. However, DIR_DELETED is wrongly defined as 0xFFFF0321, which could be a valid cluster number. To fix it, let's redefine DIR_DELETED as 0xFFFFFFF7, the bad cluster number. Fixes: 1acf1a564b60 ("exfat: add in-memory and on-disk structures and headers") Cc: stable@vger.kernel.org # v5.7+ Reported-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2023-01-19fs: port ->getattr() to pass mnt_idmapChristian Brauner
Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19fs: port ->setattr() to pass mnt_idmapChristian Brauner
Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-12-13exfat: fix overflow in sector and cluster conversionYuezhang Mo
According to the exFAT specification, there are at most 2^32-11 clusters in a volume. so using 'int' is not enough for cluster index, the return value type of exfat_sector_to_cluster() should be 'unsigned int'. Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-12-12exfat: remove i_size_write() from __exfat_truncate()Yuezhang Mo
The file/directory size is updated into inode by i_size_write() before __exfat_truncate() is called, so it is redundant to re-update by i_size_write() in __exfat_truncate(). Code refinement, no functional changes. Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Reviewed-by: Andy Wu <Andy.Wu@sony.com> Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-12-12exfat: remove argument 'size' from exfat_truncate()Yuezhang Mo
argument 'size' is not used in exfat_truncate(), remove it. Code refinement, no functional changes. Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Reviewed-by: Andy Wu <Andy.Wu@sony.com> Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-12-12exfat: remove unnecessary arguments from exfat_find_dir_entry()Yuezhang Mo
This commit removes argument 'num_entries' and 'type' from exfat_find_dir_entry(). Code refinement, no functional changes. Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Reviewed-by: Andy Wu <Andy.Wu@sony.com> Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-12-12exfat: remove call ilog2() from exfat_readdir()Yuezhang Mo
There is no need to call ilog2() for the conversions between cluster and dentry in exfat_readdir(), because these conversions can be replaced with EXFAT_DEN_TO_CLU()/EXFAT_CLU_TO_DEN(). Code refinement, no functional changes. Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Reviewed-by: Andy Wu <Andy.Wu@sony.com> Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-12-12exfat: rename exfat_free_dentry_set() to exfat_put_dentry_set()Yuezhang Mo
Since struct exfat_entry_set_cache is allocated from stack, no need to free, so rename exfat_free_dentry_set() to exfat_put_dentry_set(). After renaming, the new function pair is exfat_get_dentry_set()/exfat_put_dentry_set(). Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Reviewed-by: Andy Wu <Andy.Wu@sony.com> Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-12-12exfat: move exfat_entry_set_cache from heap to stackYuezhang Mo
The size of struct exfat_entry_set_cache is only 56 bytes on 64-bit system, and allocating from stack is more efficient than allocating from heap. Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Reviewed-by: Andy Wu <Andy.Wu@sony.com> Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-12-12exfat: support dynamic allocate bh for exfat_entry_set_cacheYuezhang Mo
In special cases, a file or a directory may occupied more than 19 directory entries, pre-allocating 3 bh is not enough. Such as - Support vendor secondary directory entry in the future. - Since file directory entry is damaged, the SecondaryCount field is bigger than 18. So this commit supports dynamic allocation of bh. Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Reviewed-by: Andy Wu <Andy.Wu@sony.com> Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-12-12exfat: reduce the size of exfat_entry_set_cacheYuezhang Mo
In normal, there are 19 directory entries at most for a file or a directory. - A file directory entry - A stream extension directory entry - 1~17 file name directory entry So the directory entries are in 3 sectors at most, it is enough for struct exfat_entry_set_cache to pre-allocate 3 bh. This commit changes the size of struct exfat_entry_set_cache as: Before After 32-bit system 88 32 bytes 64-bit system 168 48 bytes Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Reviewed-by: Andy Wu <Andy.Wu@sony.com> Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-08-01exfat: Expand exfat_err() and co directly to pr_*() macroTakashi Iwai
Currently the error and info messages handled by exfat_err() and co are tossed to exfat_msg() function that does nothing but passes the strings with printk() invocation. Not only that this is more overhead by the indirect calls, but also this makes harder to extend for the debug print usage; because of the direct printk() call, you cannot make it for dynamic debug or without debug like the standard helpers such as pr_debug() or dev_dbg(). For addressing the problem, this patch replaces exfat_*() macro to expand to pr_*() directly. Along with it, add the new exfat_debug() macro that is expanded to pr_debug() (which output can be gracefully suppressed via dyndbg). Reviewed-by: Petr Vorel <pvorel@suse.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-08-01exfat: Define NLS_NAME_* as bit flags explicitlyTakashi Iwai
NLS_NAME_* are bit flags although they are currently defined as enum; it's casually working so far (from 0 to 2), but it's error-prone and may bring a problem when we want to add more flag. This patch changes the definitions of NLS_NAME_* explicitly being bit flags. Reviewed-by: Petr Vorel <pvorel@suse.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-08-01exfat: reuse __exfat_write_inode() to update directory entryYuezhang Mo
__exfat_write_inode() is used to update file and stream directory entries, except for file->start_clu and stream->flags. This commit moves update file->start_clu and stream->flags to __exfat_write_inode() and reuse __exfat_write_inode() to update directory entries. Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Reviewed-by: Andy Wu <Andy.Wu@sony.com> Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com> Reviewed-by: Daniel Palmer <daniel.palmer@sony.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-05-23exfat: check if cluster num is validTadeusz Struk
Syzbot reported slab-out-of-bounds read in exfat_clear_bitmap. This was triggered by reproducer calling truncute with size 0, which causes the following trace: BUG: KASAN: slab-out-of-bounds in exfat_clear_bitmap+0x147/0x490 fs/exfat/balloc.c:174 Read of size 8 at addr ffff888115aa9508 by task syz-executor251/365 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118 print_address_description+0x81/0x3c0 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report+0x1a4/0x1f0 mm/kasan/report.c:436 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 exfat_clear_bitmap+0x147/0x490 fs/exfat/balloc.c:174 exfat_free_cluster+0x25a/0x4a0 fs/exfat/fatent.c:181 __exfat_truncate+0x99e/0xe00 fs/exfat/file.c:217 exfat_truncate+0x11b/0x4f0 fs/exfat/file.c:243 exfat_setattr+0xa03/0xd40 fs/exfat/file.c:339 notify_change+0xb76/0xe10 fs/attr.c:336 do_truncate+0x1ea/0x2d0 fs/open.c:65 Move the is_valid_cluster() helper from fatent.c to a common header to make it reusable in other *.c files. And add is_valid_cluster() to validate if cluster number is within valid range in exfat_clear_bitmap() and exfat_set_bitmap(). Link: https://syzkaller.appspot.com/bug?id=50381fc73821ecae743b8cf24b4c9a04776f767c Reported-by: syzbot+a4087e40b9c13aad7892@syzkaller.appspotmail.com Fixes: 1e49a94cf707 ("exfat: add bitmap operations") Cc: stable@vger.kernel.org # v5.7+ Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-05-23exfat: introduce mount option 'sys_tz'Chung-Chiang Cheng
EXFAT_TZ_VALID bit in {create,modify,access}_tz is corresponding to OffsetValid field in exfat specification [1]. When this bit isn't set, timestamps should be treated as having the same UTC offset as the current local time. Currently, there is an option 'time_offset' for users to specify the UTC offset for this issue. This patch introduces a new mount option 'sys_tz' to use system timezone as time offset. Link: [1] https://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification#74102-offsetvalid-field Signed-off-by: Chung-Chiang Cheng <cccheng@synology.com> Acked-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-04-01exfat: allow access to paths with trailing dotsVasant Karasulli
The Linux kernel exfat driver currently unconditionally strips trailing periods '.' from path components. This isdone intentionally, loosely following Windows behaviour and specifications which state: #exFAT The concatenated file name has the same set of illegal characters as other FAT-based file systems (see Table 31). #FAT ... Leading and trailing spaces in a long name are ignored. Leading and embedded periods are allowed in a name and are stored in the long name. Trailing periods are ignored. Note: Leading and trailing space ' ' characters are currently retained by Linux kernel exfat, in conflict with the above specification. On Windows 10, trailing and leading space ' ' characters are stripped from the filenames. Some implementations, such as fuse-exfat, don't perform path trailer removal. When mounting images which contain trailing-dot paths, these paths are unreachable, e.g.: + mount.exfat-fuse /dev/zram0 /mnt/test/ FUSE exfat 1.3.0 + cd /mnt/test/ + touch fuse_created_dots... ' fuse_created_spaces ' + ls -l total 0 -rwxrwxrwx 1 root 0 0 Aug 18 09:45 ' fuse_created_spaces ' -rwxrwxrwx 1 root 0 0 Aug 18 09:45 fuse_created_dots... + cd / + umount /mnt/test/ + mount -t exfat /dev/zram0 /mnt/test + cd /mnt/test + ls -l ls: cannot access 'fuse_created_dots...': No such file or directory total 0 -rwxr-xr-x 1 root 0 0 Aug 18 09:45 ' fuse_created_spaces ' -????????? ? ? ? ? ? fuse_created_dots... + touch kexfat_created_dots... ' kexfat_created_spaces ' + ls -l ls: cannot access 'fuse_created_dots...': No such file or directory total 0 -rwxr-xr-x 1 root 0 0 Aug 18 09:45 ' fuse_created_spaces ' -rwxr-xr-x 1 root 0 0 Aug 18 09:45 ' kexfat_created_spaces ' -????????? ? ? ? ? ? fuse_created_dots... -rwxr-xr-x 1 root 0 0 Aug 18 09:45 kexfat_created_dots + cd / + umount /mnt/test/ This commit adds "keep_last_dots" mount option that controls whether or not trailing periods '.' are stripped from path components during file lookup or file creation. This mount option can be used to access paths with trailing periods and disallow creating files with names with trailing periods. E.g. continuing from the previous example: + mount -t exfat -o keep_last_dots /dev/zram0 /mnt/test + cd /mnt/test + ls -l total 0 -rwxr-xr-x 1 root 0 0 Aug 18 10:32 ' fuse_created_spaces ' -rwxr-xr-x 1 root 0 0 Aug 18 10:32 ' kexfat_created_spaces ' -rwxr-xr-x 1 root 0 0 Aug 18 10:32 fuse_created_dots... -rwxr-xr-x 1 root 0 0 Aug 18 10:32 kexfat_created_dots + echo > kexfat_created_dots_again... sh: kexfat_created_dots_again...: Invalid argument Link: https://bugzilla.suse.com/show_bug.cgi?id=1188964 Link: https://lore.kernel.org/linux-fsdevel/003b01d755e4$31fb0d80$95f12880$ @samsung.com/ Link: https://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification Suggested-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Vasant Karasulli <vkarasulli@suse.de> Co-developed-by: David Disseldorp <ddiss@suse.de> Signed-off-by: David Disseldorp <ddiss@suse.de> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-01-10exfat: remove argument 'sector' from exfat_get_dentry()Yuezhang.Mo
No any function uses argument 'sector', remove it. Reviewed-by: Andy.Wu <Andy.Wu@sony.com> Reviewed-by: Aoyama, Wataru <wataru.aoyama@sony.com> Acked-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Yuezhang.Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-01-10exfat: move super block magic number to magic.hNamjae Jeon
Move exfat superblock magic number from local definition to magic.h. It is also needed by userspace programs that call fstatfs(). Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-01-10exfat: make exfat_find_location() staticChristophe Vu-Brugier
Make exfat_find_location() static. Signed-off-by: Christophe Vu-Brugier <christophe.vu-brugier@seagate.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2021-04-27exfat: speed up iterate/lookup by fixing start point of traversing cluster chainHyeongseok Kim
When directory iterate and lookup is called, there's a buggy rewinding of start point for traversing cluster chain to the parent directory entry's first cluster. This caused repeated cluster chain traversing from the first entry of the parent directory that would show worse performance if huge amounts of files exist under the parent directory. Fix not to rewind, make continue from currently referenced cluster and dir entry. Tested with 50,000 files under single directory / 256GB sdcard, with command "time ls -l > /dev/null", Before : 0m08.69s real 0m00.27s user 0m05.91s system After : 0m07.01s real 0m00.25s user 0m04.34s system Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2021-04-27exfat: improve write performance when dirsync enabledHyeongseok Kim
Degradation of write speed caused by frequent disk access for cluster bitmap update on every cluster allocation could be improved by selective syncing bitmap buffer. Change to flush bitmap buffer only for the directory related operations. Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com> Acked-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2021-04-27exfat: add support ioctl and FITRIM functionHyeongseok Kim
Add FITRIM ioctl to enable discarding unused blocks while mounted. As current exFAT doesn't have generic ioctl handler, add empty ioctl function first, and add FITRIM handler. Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2021-04-27exfat: introduce bitmap_lock for cluster bitmap accessHyeongseok Kim
s_lock which is for protecting concurrent access of file operations is too huge for cluster bitmap protection, so introduce a new bitmap_lock to narrow the lock range if only need to access cluster bitmap. Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com> Acked-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2021-02-23Merge tag 'idmapped-mounts-v5.12' of ↵Linus Torvalds
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 ...
2021-02-22exfat: improve performance of exfat_free_cluster when using dirsync mount optionHyeongseok Kim
There are stressful update of cluster allocation bitmap when using dirsync mount option which is doing sync buffer on every cluster bit clearing. This could result in performance degradation when deleting big size file. Fix to update only when the bitmap buffer index is changed would make less disk access, improving performance especially for truncate operation. Testing with Samsung 256GB sdcard, mounted with dirsync option (mount -t exfat /dev/block/mmcblk0p1 /temp/mount -o dirsync) Remove 4GB file, blktrace result. [Before] : 39 secs. Total (blktrace): Reads Queued: 0, 0KiB Writes Queued: 32775, 16387KiB Read Dispatches: 0, 0KiB Write Dispatches: 32775, 16387KiB Reads Requeued: 0 Writes Requeued: 0 Reads Completed: 0, 0KiB Writes Completed: 32775, 16387KiB Read Merges: 0, 0KiB Write Merges: 0, 0KiB IO unplugs: 2 Timer unplugs: 0 [After] : 1 sec. Total (blktrace): Reads Queued: 0, 0KiB Writes Queued: 13, 6KiB Read Dispatches: 0, 0KiB Write Dispatches: 13, 6KiB Reads Requeued: 0 Writes Requeued: 0 Reads Completed: 0, 0KiB Writes Completed: 13, 6KiB Read Merges: 0, 0KiB Write Merges: 0, 0KiB IO unplugs: 1 Timer unplugs: 0 Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com> Acked-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2021-01-24fs: make helpers idmap mount awareChristian Brauner
Extend some inode methods with an additional user namespace argument. A filesystem that is aware of idmapped mounts will receive the user namespace the mount has been marked with. This can be used for additional permission checking and also to enable filesystems to translate between uids and gids if they need to. We have implemented all relevant helpers in earlier patches. As requested we simply extend the exisiting inode method instead of introducing new ones. This is a little more code churn but it's mostly mechanical and doesnt't leave us with additional inode methods. Link: https://lore.kernel.org/r/20210121131959.646623-25-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> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-10-22exfat: remove 'rwoffset' in exfat_inode_infoTetsuhiro Kohada
Remove 'rwoffset' in exfat_inode_info and replace it with the parameter of exfat_readdir(). Since rwoffset is referenced only by exfat_readdir(), it is not necessary a exfat_inode_info's member. Also, change cpos to point to the next of entry-set, and return the index of dir-entry via dir_entry->entry. Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Acked-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-10-22exfat: fix misspellings using codespell toolNamjae Jeon
Sedat reported typos using codespell tool. $ codespell fs/exfat/*.c | grep -v iput fs/exfat/namei.c:293: upto ==> up to fs/exfat/nls.c:14: tabel ==> table $ codespell fs/exfat/*.h fs/exfat/exfat_fs.h:133: usally ==> usually Fix typos found by codespell. Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-10-07exfat: fix use of uninitialized spinlock on error pathNamjae Jeon
syzbot reported warning message: Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d6/0x29e lib/dump_stack.c:118 register_lock_class+0xf06/0x1520 kernel/locking/lockdep.c:893 __lock_acquire+0xfd/0x2ae0 kernel/locking/lockdep.c:4320 lock_acquire+0x148/0x720 kernel/locking/lockdep.c:5029 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] exfat_cache_inval_inode+0x30/0x280 fs/exfat/cache.c:226 exfat_evict_inode+0x124/0x270 fs/exfat/inode.c:660 evict+0x2bb/0x6d0 fs/inode.c:576 exfat_fill_super+0x1e07/0x27d0 fs/exfat/super.c:681 get_tree_bdev+0x3e9/0x5f0 fs/super.c:1342 vfs_get_tree+0x88/0x270 fs/super.c:1547 do_new_mount fs/namespace.c:2875 [inline] path_mount+0x179d/0x29e0 fs/namespace.c:3192 do_mount fs/namespace.c:3205 [inline] __do_sys_mount fs/namespace.c:3413 [inline] __se_sys_mount+0x126/0x180 fs/namespace.c:3390 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 If exfat_read_root() returns an error, spinlock is used in exfat_evict_inode() without initialization. This patch combines exfat_cache_init_inode() with exfat_inode_init_once() to initialize spinlock by slab constructor. Fixes: c35b6810c495 ("exfat: add exfat cache") Cc: stable@vger.kernel.org # v5.7+ Reported-by: syzbot <syzbot+b91107320911a26c9a95@syzkaller.appspotmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-08-12exfat: retain 'VolumeFlags' properlyTetsuhiro Kohada
MediaFailure and VolumeDirty should be retained if these are set before mounting. In '3.1.13.3 Media Failure Field' of exfat specification describe: If, upon mounting a volume, the value of this field is 1, implementations which scan the entire volume for media failures and record all failures as "bad" clusters in the FAT (or otherwise resolve media failures) may clear the value of this field to 0. Therefore, We should not clear MediaFailure without scanning volume. In '8.1 Recommended Write Ordering' of exfat specification describe: Clear the value of the VolumeDirty field to 0, if its value prior to the first step was 0. Therefore, We should not clear VolumeDirty after mounting. Also rename ERR_MEDIUM to MEDIA_FAILURE. Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-08-12exfat: add error check when updating dir-entriesTetsuhiro Kohada
Add error check when synchronously updating dir-entries. Suggested-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-08-12exfat: write multiple sectors at onceTetsuhiro Kohada
Write multiple sectors at once when updating dir-entries. Add exfat_update_bhs() for that. It wait for write completion once instead of sector by sector. It's only effective if sync enabled. Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-08-12exfat: remove EXFAT_SB_DIRTY flagTetsuhiro Kohada
This flag is set/reset in exfat_put_super()/exfat_sync_fs() to avoid sync_blockdev(). - exfat_put_super(): Before calling this, the VFS has already called sync_filesystem(), so sync is never performed here. - exfat_sync_fs(): After calling this, the VFS calls sync_blockdev(), so, it is meaningless to check EXFAT_SB_DIRTY or to bypass sync_blockdev() here. Remove the EXFAT_SB_DIRTY check to ensure synchronization. And remove the code related to the flag. Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-07-21exfat: fix overflow issue in exfat_cluster_to_sector()Namjae Jeon
An overflow issue can occur while calculating sector in exfat_cluster_to_sector(). It needs to cast clus's type to sector_t before left shifting. Fixes: 1acf1a564b60 ("exfat: add in-memory and on-disk structures and headers") Cc: stable@vger.kernel.org # v5.7 Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-29exfat: flush dirty metadata in fsyncSungjong Seo
generic_file_fsync() exfat used could not guarantee the consistency of a file because it has flushed not dirty metadata but only dirty data pages for a file. Instead of that, use exfat_file_fsync() for files and directories so that it guarantees to commit both the metadata and data pages for a file. Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09exfat: standardize checksum calculationTetsuhiro Kohada
To clarify that it is a 16-bit checksum, the parts related to the 16-bit checksum are renamed and change type to u16. Furthermore, replace checksum calculation in exfat_load_upcase_table() with exfat_calc_checksum32(). Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09exfat: add boot region verificationTetsuhiro Kohada
Add Boot-Regions verification specified in exFAT specification. Note that the checksum type is strongly related to the raw structure, so the'u32 'type is used to clarify the number of bits. Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09exfat: redefine PBR as boot_sectorTetsuhiro Kohada
Aggregate PBR related definitions and redefine as "boot_sector" to comply with the exFAT specification. And, rename variable names including 'pbr'. Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09exfat: optimize dir-cacheTetsuhiro Kohada
Optimize directory access based on exfat_entry_set_cache. - Hold bh instead of copied d-entry. - Modify bh->data directly instead of the copied d-entry. - Write back the retained bh instead of rescanning the d-entry-set. And - Remove unused cache related definitions. Signed-off-by: Tetsuhiro Kohada <kohada.tetsuhiro@dc.mitsubishielectric.co.jp> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09exfat: replace 'time_ms' with 'time_cs'Tetsuhiro Kohada
Replace time_ms with time_cs in the file directory entry structure and related functions. The unit of create_time_ms/modify_time_ms in File Directory Entry are not 'milli-second', but 'centi-second'. The exfat specification uses the term '10ms', but instead use 'cs' as in msdos_fs.h. Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09exfat: Remove unused functions exfat_high_surrogate() and exfat_low_surrogate()Pali Rohár
After applying previous two patches, these functions are not used anymore. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09exfat: Use a more common logging styleJoe Perches
Remove the direct use of KERN_<LEVEL> in functions by creating separate exfat_<level> macros. Miscellanea: o Remove several unnecessary terminating newlines in formats o Realign arguments and fit to 80 columns where appropriate Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-04-22exfat: truncate atimes to 2s granularityEric Sandeen
The timestamp for access_time has double seconds granularity(There is no 10msIncrement field for access_time unlike create/modify_time). exfat's atimes are restricted to only 2s granularity so after we set an atime, round it down to the nearest 2s and set the sub-second component of the timestamp to 0. Signed-off-by: Eric Sandeen <sandeen@sandeen.net> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-03-05exfat: add in-memory and on-disk structures and headersNamjae Jeon
This adds in-memory and on-disk structures and headers. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com> Reviewed-by: Pali Rohár <pali.rohar@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>