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* fs: port fs{g,u}id helpers to mnt_idmapChristian Brauner2023-01-191-2/+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 inode_init_owner() to mnt_idmapChristian Brauner2023-01-191-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | 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 'ext4_for_linus' of ↵Linus Torvalds2022-12-121-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: "A large number of cleanups and bug fixes, with many of the bug fixes found by Syzbot and fuzzing. (Many of the bug fixes involve less-used ext4 features such as fast_commit, inline_data and bigalloc) In addition, remove the writepage function for ext4, since the medium-term plan is to remove ->writepage() entirely. (The VM doesn't need or want writepage() for writeback, since it is fine with ->writepages() so long as ->migrate_folio() is implemented)" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (58 commits) ext4: fix reserved cluster accounting in __es_remove_extent() ext4: fix inode leak in ext4_xattr_inode_create() on an error path ext4: allocate extended attribute value in vmalloc area ext4: avoid unaccounted block allocation when expanding inode ext4: initialize quota before expanding inode in setproject ioctl ext4: stop providing .writepage hook mm: export buffer_migrate_folio_norefs() ext4: switch to using write_cache_pages() for data=journal writeout jbd2: switch jbd2_submit_inode_data() to use fs-provided hook for data writeout ext4: switch to using ext4_do_writepages() for ordered data writeout ext4: move percpu_rwsem protection into ext4_writepages() ext4: provide ext4_do_writepages() ext4: add support for writepages calls that cannot map blocks ext4: drop pointless IO submission from ext4_bio_write_page() ext4: remove nr_submitted from ext4_bio_write_page() ext4: move keep_towrite handling to ext4_bio_write_page() ext4: handle redirtying in ext4_bio_write_page() ext4: fix kernel BUG in 'ext4_write_inline_data_end()' ext4: make ext4_mb_initialize_context return void ext4: fix deadlock due to mbcache entry corruption ...
| * ext4: split ext4_journal_start trace for debugchangfengnan2022-12-011-2/+2
| | | | | | | | | | | | | | | | | | | | we might want to know why jbd2 thread using high io for detail, split ext4_journal_start trace to ext4_journal_start_sb and ext4_journal_start_inode, show ino and handle type when possible. Signed-off-by: changfengnan <changfengnan@bytedance.com> Link: https://lore.kernel.org/r/20221008120518.74870-1-changfengnan@bytedance.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* | Merge tag 'fs.acl.rework.v6.2' of ↵Linus Torvalds2022-12-121-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping Pull VFS acl updates from Christian Brauner: "This contains the work that builds a dedicated vfs posix acl api. The origins of this work trace back to v5.19 but it took quite a while to understand the various filesystem specific implementations in sufficient detail and also come up with an acceptable solution. As we discussed and seen multiple times the current state of how posix acls are handled isn't nice and comes with a lot of problems: The current way of handling posix acls via the generic xattr api is error prone, hard to maintain, and type unsafe for the vfs until we call into the filesystem's dedicated get and set inode operations. It is already the case that posix acls are special-cased to death all the way through the vfs. There are an uncounted number of hacks that operate on the uapi posix acl struct instead of the dedicated vfs struct posix_acl. And the vfs must be involved in order to interpret and fixup posix acls before storing them to the backing store, caching them, reporting them to userspace, or for permission checking. Currently a range of hacks and duct tape exist to make this work. As with most things this is really no ones fault it's just something that happened over time. But the code is hard to understand and difficult to maintain and one is constantly at risk of introducing bugs and regressions when having to touch it. Instead of continuing to hack posix acls through the xattr handlers this series builds a dedicated posix acl api solely around the get and set inode operations. Going forward, the vfs_get_acl(), vfs_remove_acl(), and vfs_set_acl() helpers must be used in order to interact with posix acls. They operate directly on the vfs internal struct posix_acl instead of abusing the uapi posix acl struct as we currently do. In the end this removes all of the hackiness, makes the codepaths easier to maintain, and gets us type safety. This series passes the LTP and xfstests suites without any regressions. For xfstests the following combinations were tested: - xfs - ext4 - btrfs - overlayfs - overlayfs on top of idmapped mounts - orangefs - (limited) cifs There's more simplifications for posix acls that we can make in the future if the basic api has made it. A few implementation details: - The series makes sure to retain exactly the same security and integrity module permission checks. Especially for the integrity modules this api is a win because right now they convert the uapi posix acl struct passed to them via a void pointer into the vfs struct posix_acl format to perform permission checking on the mode. There's a new dedicated security hook for setting posix acls which passes the vfs struct posix_acl not a void pointer. Basing checking on the posix acl stored in the uapi format is really unreliable. The vfs currently hacks around directly in the uapi struct storing values that frankly the security and integrity modules can't correctly interpret as evidenced by bugs we reported and fixed in this area. It's not necessarily even their fault it's just that the format we provide to them is sub optimal. - Some filesystems like 9p and cifs need access to the dentry in order to get and set posix acls which is why they either only partially or not even at all implement get and set inode operations. For example, cifs allows setxattr() and getxattr() operations but doesn't allow permission checking based on posix acls because it can't implement a get acl inode operation. Thus, this patch series updates the set acl inode operation to take a dentry instead of an inode argument. However, for the get acl inode operation we can't do this as the old get acl method is called in e.g., generic_permission() and inode_permission(). These helpers in turn are called in various filesystem's permission inode operation. So passing a dentry argument to the old get acl inode operation would amount to passing a dentry to the permission inode operation which we shouldn't and probably can't do. So instead of extending the existing inode operation Christoph suggested to add a new one. He also requested to ensure that the get and set acl inode operation taking a dentry are consistently named. So for this version the old get acl operation is renamed to ->get_inode_acl() and a new ->get_acl() inode operation taking a dentry is added. With this we can give both 9p and cifs get and set acl inode operations and in turn remove their complex custom posix xattr handlers. In the future I hope to get rid of the inode method duplication but it isn't like we have never had this situation. Readdir is just one example. And frankly, the overall gain in type safety and the more pleasant api wise are simply too big of a benefit to not accept this duplication for a while. - We've done a full audit of every codepaths using variant of the current generic xattr api to get and set posix acls and surprisingly it isn't that many places. There's of course always a chance that we might have missed some and if so I'm sure we'll find them soon enough. The crucial codepaths to be converted are obviously stacking filesystems such as ecryptfs and overlayfs. For a list of all callers currently using generic xattr api helpers see [2] including comments whether they support posix acls or not. - The old vfs generic posix acl infrastructure doesn't obey the create and replace semantics promised on the setxattr(2) manpage. This patch series doesn't address this. It really is something we should revisit later though. The patches are roughly organized as follows: (1) Change existing set acl inode operation to take a dentry argument (Intended to be a non-functional change) (2) Rename existing get acl method (Intended to be a non-functional change) (3) Implement get and set acl inode operations for filesystems that couldn't implement one before because of the missing dentry. That's mostly 9p and cifs (Intended to be a non-functional change) (4) Build posix acl api, i.e., add vfs_get_acl(), vfs_remove_acl(), and vfs_set_acl() including security and integrity hooks (Intended to be a non-functional change) (5) Implement get and set acl inode operations for stacking filesystems (Intended to be a non-functional change) (6) Switch posix acl handling in stacking filesystems to new posix acl api now that all filesystems it can stack upon support it. (7) Switch vfs to new posix acl api (semantical change) (8) Remove all now unused helpers (9) Additional regression fixes reported after we merged this into linux-next Thanks to Seth for a lot of good discussion around this and encouragement and input from Christoph" * tag 'fs.acl.rework.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (36 commits) posix_acl: Fix the type of sentinel in get_acl orangefs: fix mode handling ovl: call posix_acl_release() after error checking evm: remove dead code in evm_inode_set_acl() cifs: check whether acl is valid early acl: make vfs_posix_acl_to_xattr() static acl: remove a slew of now unused helpers 9p: use stub posix acl handlers cifs: use stub posix acl handlers ovl: use stub posix acl handlers ecryptfs: use stub posix acl handlers evm: remove evm_xattr_acl_change() xattr: use posix acl api ovl: use posix acl api ovl: implement set acl method ovl: implement get acl method ecryptfs: implement set acl method ecryptfs: implement get acl method ksmbd: use vfs_remove_acl() acl: add vfs_remove_acl() ...
| * | fs: rename current get acl methodChristian Brauner2022-10-201-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current way of setting and getting posix acls through the generic xattr interface is error prone and type unsafe. The vfs needs to interpret and fixup posix acls before storing or reporting it to userspace. Various hacks exist to make this work. The code is hard to understand and difficult to maintain in it's current form. Instead of making this work by hacking posix acls through xattr handlers we are building a dedicated posix acl api around the get and set inode operations. This removes a lot of hackiness and makes the codepaths easier to maintain. A lot of background can be found in [1]. The current inode operation for getting posix acls takes an inode argument but various filesystems (e.g., 9p, cifs, overlayfs) need access to the dentry. In contrast to the ->set_acl() inode operation we cannot simply extend ->get_acl() to take a dentry argument. The ->get_acl() inode operation is called from: acl_permission_check() -> check_acl() -> get_acl() which is part of generic_permission() which in turn is part of inode_permission(). Both generic_permission() and inode_permission() are called in the ->permission() handler of various filesystems (e.g., overlayfs). So simply passing a dentry argument to ->get_acl() would amount to also having to pass a dentry argument to ->permission(). We should avoid this unnecessary change. So instead of extending the existing inode operation rename it from ->get_acl() to ->get_inode_acl() and add a ->get_acl() method later that passes a dentry argument and which filesystems that need access to the dentry can implement instead of ->get_inode_acl(). Filesystems like cifs which allow setting and getting posix acls but not using them for permission checking during lookup can simply not implement ->get_inode_acl(). This is intended to be a non-functional change. Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1] Suggested-by/Inspired-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
* / treewide: use get_random_u32_below() instead of deprecated functionJason A. Donenfeld2022-11-181-1/+1
|/ | | | | | | | | | | | | | | | | | | | This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Reviewed-by: SeongJae Park <sj@kernel.org> # for damon Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
* treewide: use get_random_u32() when possibleJason A. Donenfeld2022-10-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | The prandom_u32() function has been a deprecated inline wrapper around get_random_u32() for several releases now, and compiles down to the exact same code. Replace the deprecated wrapper with a direct call to the real function. The same also applies to get_random_int(), which is just a wrapper around get_random_u32(). This was done as a basic find and replace. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Acked-by: Helge Deller <deller@gmx.de> # for parisc Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
* treewide: use prandom_u32_max() when possible, part 2Jason A. Donenfeld2022-10-111-3/+2
| | | | | | | | | | | | | | Rather than incurring a division or requesting too many random bytes for the given range, use the prandom_u32_max() function, which only takes the minimum required bytes from the RNG and avoids divisions. This was done by hand, covering things that coccinelle could not do on its own. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> # for ext2, ext4, and sbitmap Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
* ext4: make directory inode spreading reflect flexbg sizeJan Kara2022-09-211-1/+1
| | | | | | | | | | | | | | | | | Currently the Orlov inode allocator searches for free inodes for a directory only in flex block groups with at most inodes_per_group/16 more directory inodes than average per flex block group. However with growing size of flex block group this becomes unnecessarily strict. Scale allowed difference from average directory count per flex block group with flex block group size as we do with other metrics. Tested-by: Stefan Wahren <stefan.wahren@i2se.com> Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Cc: stable@kernel.org Link: https://lore.kernel.org/all/0d81a7c2-46b7-6010-62a4-3e6cfc1628d6@i2se.com/ Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220908092136.11770-3-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: Support for checksumming from journal triggersJan Kara2021-08-301-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | JBD2 layer support triggers which are called when journaling layer moves buffer to a certain state. We can use the frozen trigger, which gets called when buffer data is frozen and about to be written out to the journal, to compute block checksums for some buffer types (similarly as does ocfs2). This avoids unnecessary repeated recomputation of the checksum (at the cost of larger window where memory corruption won't be caught by checksumming) and is even necessary when there are unsynchronized updaters of the checksummed data. So add superblock and journal trigger type arguments to ext4_journal_get_write_access() and ext4_journal_get_create_access() so that frozen triggers can be set accordingly. Also add inode argument to ext4_walk_page_buffers() and all the callbacks used with that function for the same purpose. This patch is mostly only a change of prototype of the above mentioned functions and a few small helpers. Real checksumming will come later. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210816095713.16537-1-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: fix avefreec in find_group_orlovPan Dong2021-06-221-6/+5
| | | | | | | | | | | The avefreec should be average free clusters instead of average free blocks, otherwize Orlov's allocator will not work properly when bigalloc enabled. Cc: stable@kernel.org Signed-off-by: Pan Dong <pandong.peter@bytedance.com> Link: https://lore.kernel.org/r/20210525073656.31594-1-pandong.peter@bytedance.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds2021-06-061-2/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "Miscellaneous ext4 bug fixes" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: Only advertise encrypted_casefold when encryption and unicode are enabled ext4: fix no-key deletion for encrypt+casefold ext4: fix memory leak in ext4_fill_super ext4: fix fast commit alignment issues ext4: fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed ext4: fix accessing uninit percpu counter variable with fast_commit ext4: fix memory leak in ext4_mb_init_backend on error path.
| * ext4: fix accessing uninit percpu counter variable with fast_commitRitesh Harjani2021-06-021-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running generic/527 with fast_commit configuration, the following issue is seen on Power. With fast_commit, during ext4_fc_replay() (which can be called from ext4_fill_super()), if inode eviction happens then it can access an uninitialized percpu counter variable. This patch adds the check before accessing the counters in ext4_free_inode() path. [ 321.165371] run fstests generic/527 at 2021-04-29 08:38:43 [ 323.027786] EXT4-fs (dm-0): mounted filesystem with ordered data mode. Opts: block_validity. Quota mode: none. [ 323.618772] BUG: Unable to handle kernel data access on read at 0x1fbd80000 [ 323.619767] Faulting instruction address: 0xc000000000bae78c cpu 0x1: Vector: 300 (Data Access) at [c000000010706ef0] pc: c000000000bae78c: percpu_counter_add_batch+0x3c/0x100 lr: c0000000006d0bb0: ext4_free_inode+0x780/0xb90 pid = 5593, comm = mount ext4_free_inode+0x780/0xb90 ext4_evict_inode+0xa8c/0xc60 evict+0xfc/0x1e0 ext4_fc_replay+0xc50/0x20f0 do_one_pass+0xfe0/0x1350 jbd2_journal_recover+0x184/0x2e0 jbd2_journal_load+0x1c0/0x4a0 ext4_fill_super+0x2458/0x4200 mount_bdev+0x1dc/0x290 ext4_mount+0x28/0x40 legacy_get_tree+0x4c/0xa0 vfs_get_tree+0x4c/0x120 path_mount+0xcf8/0xd70 do_mount+0x80/0xd0 sys_mount+0x3fc/0x490 system_call_exception+0x384/0x3d0 system_call_common+0xec/0x278 Cc: stable@kernel.org Fixes: 8016e29f4362 ("ext4: fast commit recovery path") Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/6cceb9a75c54bef8fa9696c1b08c8df5ff6169e2.1619692410.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* | Merge tag 'ext4_for_linus' of ↵Linus Torvalds2021-04-301-17/+34
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: "New features for ext4 this cycle include support for encrypted casefold, ensure that deleted file names are cleared in directory blocks by zeroing directory entries when they are unlinked or moved as part of a hash tree node split. We also improve the block allocator's performance on a freshly mounted file system by prefetching block bitmaps. There are also the usual cleanups and bug fixes, including fixing a page cache invalidation race when there is mixed buffered and direct I/O and the block size is less than page size, and allow the dax flag to be set and cleared on inline directories" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (32 commits) ext4: wipe ext4_dir_entry2 upon file deletion ext4: Fix occasional generic/418 failure fs: fix reporting supported extra file attributes for statx() ext4: allow the dax flag to be set and cleared on inline directories ext4: fix debug format string warning ext4: fix trailing whitespace ext4: fix various seppling typos ext4: fix error return code in ext4_fc_perform_commit() ext4: annotate data race in jbd2_journal_dirty_metadata() ext4: annotate data race in start_this_handle() ext4: fix ext4_error_err save negative errno into superblock ext4: fix error code in ext4_commit_super ext4: always panic when errors=panic is specified ext4: delete redundant uptodate check for buffer ext4: do not set SB_ACTIVE in ext4_orphan_cleanup() ext4: make prefetch_block_bitmaps default ext4: add proc files to monitor new structures ext4: improve cr 0 / cr 1 group scanning ext4: add MB_NUM_ORDERS macro ext4: add mballoc stats proc file ...
| * ext4: allow the dax flag to be set and cleared on inline directoriesTheodore Ts'o2021-04-121-1/+2
| | | | | | | | | | | | | | | | | | | | This is needed to allow generic/607 to pass for file systems with the inline data_feature enabled, and it allows the use of file systems where the directories use inline_data, while the files are accessed via DAX. Cc: stable@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| * ext4: fix check to prevent false positive report of incorrect used inodesZhang Yi2021-04-091-16/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit <50122847007> ("ext4: fix check to prevent initializing reserved inodes") check the block group zero and prevent initializing reserved inodes. But in some special cases, the reserved inode may not all belong to the group zero, it may exist into the second group if we format filesystem below. mkfs.ext4 -b 4096 -g 8192 -N 1024 -I 4096 /dev/sda So, it will end up triggering a false positive report of a corrupted file system. This patch fix it by avoid check reserved inodes if no free inode blocks will be zeroed. Cc: stable@kernel.org Fixes: 50122847007 ("ext4: fix check to prevent initializing reserved inodes") Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Suggested-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210331121516.2243099-1-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* | fs: introduce two inode i_{u,g}id initialization helpersChristian Brauner2021-03-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Give filesystem two little helpers that do the right thing when initializing the i_uid and i_gid fields on idmapped and non-idmapped mounts. Filesystems shouldn't have to be concerned with too many details. Link: https://lore.kernel.org/r/20210320122623.599086-5-christian.brauner@ubuntu.com Inspired-by: Vivek Goyal <vgoyal@redhat.com> Cc: Christoph Hellwig <hch@lst.de> 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>
* | fs: document and rename fsid helpersChristian Brauner2021-03-231-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | Vivek pointed out that the fs{g,u}id_into_mnt() naming scheme can be misleading as it could be understood as implying they do the exact same thing as i_{g,u}id_into_mnt(). The original motivation for this naming scheme was to signal to callers that the helpers will always take care to map the k{g,u}id such that the ownership is expressed in terms of the mnt_users. Get rid of the confusion by renaming those helpers to something more sensible. Al suggested mapped_fs{g,u}id() which seems a really good fit. Usually filesystems don't need to bother with these helpers directly only in some cases where they allocate objects that carry {g,u}ids which are either filesystem specific (e.g. xfs quota objects) or don't have a clean set of helpers as inodes have. Link: https://lore.kernel.org/r/20210320122623.599086-3-christian.brauner@ubuntu.com Inspired-by: Vivek Goyal <vgoyal@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Darrick J. Wong <djwong@kernel.org> 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>
* Merge tag 'idmapped-mounts-v5.12' of ↵Linus Torvalds2021-02-231-3/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * ext4: support idmapped mountsChristian Brauner2021-01-241-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enable idmapped mounts for ext4. All dedicated helpers we need for this exist. So this basically just means we're passing down the user_namespace argument from the VFS methods to the relevant helpers. Let's create simple example where we idmap an ext4 filesystem: root@f2-vm:~# truncate -s 5G ext4.img root@f2-vm:~# mkfs.ext4 ./ext4.img mke2fs 1.45.5 (07-Jan-2020) Discarding device blocks: done Creating filesystem with 1310720 4k blocks and 327680 inodes Filesystem UUID: 3fd91794-c6ca-4b0f-9964-289a000919cf Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736 Allocating group tables: done Writing inode tables: done Creating journal (16384 blocks): done Writing superblocks and filesystem accounting information: done root@f2-vm:~# losetup -f --show ./ext4.img /dev/loop0 root@f2-vm:~# mount /dev/loop0 /mnt root@f2-vm:~# ls -al /mnt/ total 24 drwxr-xr-x 3 root root 4096 Oct 28 13:34 . drwxr-xr-x 30 root root 4096 Oct 28 13:22 .. drwx------ 2 root root 16384 Oct 28 13:34 lost+found # Let's create an idmapped mount at /idmapped1 where we map uid and gid # 0 to uid and gid 1000 root@f2-vm:/# ./mount-idmapped --map-mount b:0:1000:1 /mnt/ /idmapped1/ root@f2-vm:/# ls -al /idmapped1/ total 24 drwxr-xr-x 3 ubuntu ubuntu 4096 Oct 28 13:34 . drwxr-xr-x 30 root root 4096 Oct 28 13:22 .. drwx------ 2 ubuntu ubuntu 16384 Oct 28 13:34 lost+found # Let's create an idmapped mount at /idmapped2 where we map uid and gid # 0 to uid and gid 2000 root@f2-vm:/# ./mount-idmapped --map-mount b:0:2000:1 /mnt/ /idmapped2/ root@f2-vm:/# ls -al /idmapped2/ total 24 drwxr-xr-x 3 2000 2000 4096 Oct 28 13:34 . drwxr-xr-x 31 root root 4096 Oct 28 13:39 .. drwx------ 2 2000 2000 16384 Oct 28 13:34 lost+found Let's create another example where we idmap the rootfs filesystem without a mapping for uid 0 and gid 0: # Create an idmapped mount of for a full POSIX range of rootfs under # /mnt but without a mapping for uid 0 to reduce attack surface root@f2-vm:/# ./mount-idmapped --map-mount b:1:1:65536 / /mnt/ # Since we don't have a mapping for uid and gid 0 all files owned by # uid and gid 0 should show up as uid and gid 65534: root@f2-vm:/# ls -al /mnt/ total 664 drwxr-xr-x 31 nobody nogroup 4096 Oct 28 13:39 . drwxr-xr-x 31 root root 4096 Oct 28 13:39 .. lrwxrwxrwx 1 nobody nogroup 7 Aug 25 07:44 bin -> usr/bin drwxr-xr-x 4 nobody nogroup 4096 Oct 28 13:17 boot drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:48 dev drwxr-xr-x 81 nobody nogroup 4096 Oct 28 04:00 etc drwxr-xr-x 4 nobody nogroup 4096 Oct 28 04:00 home lrwxrwxrwx 1 nobody nogroup 7 Aug 25 07:44 lib -> usr/lib lrwxrwxrwx 1 nobody nogroup 9 Aug 25 07:44 lib32 -> usr/lib32 lrwxrwxrwx 1 nobody nogroup 9 Aug 25 07:44 lib64 -> usr/lib64 lrwxrwxrwx 1 nobody nogroup 10 Aug 25 07:44 libx32 -> usr/libx32 drwx------ 2 nobody nogroup 16384 Aug 25 07:47 lost+found drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:44 media drwxr-xr-x 31 nobody nogroup 4096 Oct 28 13:39 mnt drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:44 opt drwxr-xr-x 2 nobody nogroup 4096 Apr 15 2020 proc drwx--x--x 6 nobody nogroup 4096 Oct 28 13:34 root drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:46 run lrwxrwxrwx 1 nobody nogroup 8 Aug 25 07:44 sbin -> usr/sbin drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:44 srv drwxr-xr-x 2 nobody nogroup 4096 Apr 15 2020 sys drwxrwxrwt 10 nobody nogroup 4096 Oct 28 13:19 tmp drwxr-xr-x 14 nobody nogroup 4096 Oct 20 13:00 usr drwxr-xr-x 12 nobody nogroup 4096 Aug 25 07:45 var # Since we do have a mapping for uid and gid 1000 all files owned by # uid and gid 1000 should simply show up as uid and gid 1000: root@f2-vm:/# ls -al /mnt/home/ubuntu/ total 40 drwxr-xr-x 3 ubuntu ubuntu 4096 Oct 28 00:43 . drwxr-xr-x 4 nobody nogroup 4096 Oct 28 04:00 .. -rw------- 1 ubuntu ubuntu 2936 Oct 28 12:26 .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 Link: https://lore.kernel.org/r/20210121131959.646623-39-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-ext4@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
| * inode: make init and permission helpers idmapped mount awareChristian Brauner2021-01-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | block: use an on-stack bio in blkdev_issue_flushChristoph Hellwig2021-01-271-1/+1
|/ | | | | | | | | | There is no point in allocating memory for a synchronous flush. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge tag 'ext4_for_linus' of ↵Linus Torvalds2020-10-221-20/+153
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: "The siginificant new ext4 feature this time around is Harshad's new fast_commit mode. In addition, thanks to Mauricio for fixing a race where mmap'ed pages that are being changed in parallel with a data=journal transaction commit could result in bad checksums in the failure that could cause journal replays to fail. Also notable is Ritesh's buffered write optimization which can result in significant improvements on parallel write workloads. (The kernel test robot reported a 330.6% improvement on fio.write_iops on a 96 core system using DAX) Besides that, we have the usual miscellaneous cleanups and bug fixes" Link: https://lore.kernel.org/r/20200925071217.GO28663@shao2-debian * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (46 commits) ext4: fix invalid inode checksum ext4: add fast commit stats in procfs ext4: add a mount opt to forcefully turn fast commits on ext4: fast commit recovery path jbd2: fast commit recovery path ext4: main fast-commit commit path jbd2: add fast commit machinery ext4 / jbd2: add fast commit initialization ext4: add fast_commit feature and handling for extended mount options doc: update ext4 and journalling docs to include fast commit feature ext4: Detect already used quota file early jbd2: avoid transaction reuse after reformatting ext4: use the normal helper to get the actual inode ext4: fix bs < ps issue reported with dioread_nolock mount opt ext4: data=journal: write-protect pages on j_submit_inode_data_buffers() ext4: data=journal: fixes for ext4_page_mkwrite() jbd2, ext4, ocfs2: introduce/use journal callbacks j_submit|finish_inode_data_buffers() jbd2: introduce/export functions jbd2_journal_submit|finish_inode_data_buffers() ext4: introduce ext4_sb_bread_unmovable() to replace sb_bread_unmovable() ext4: use ext4_sb_bread() instead of sb_bread() ...
| * ext4: fast commit recovery pathHarshad Shirwadkar2020-10-211-16/+152
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds fast commit recovery path support for Ext4 file system. We add several helper functions that are similar in spirit to e2fsprogs journal recovery path handlers. Example of such functions include - a simple block allocator, idempotent block bitmap update function etc. Using these routines and the fast commit log in the fast commit area, the recovery path (ext4_fc_replay()) performs fast commit log recovery. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20201015203802.3597742-8-harshadshirwadkar@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| * ext4: use common helpers in all places reading metadata bufferszhangyi (F)2020-10-181-5/+1
| | | | | | | | | | | | | | | | | | | | Revome all open codes that read metadata buffers, switch to use ext4_read_bh_*() common helpers. Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Suggested-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200924073337.861472-4-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| * ext4: clear buffer verified flag if read meta block from diskzhangyi (F)2020-10-181-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The metadata buffer is no longer trusted after we read it from disk again because it is not uptodate for some reasons (e.g. failed to write back). Otherwise we may get below memory corruption problem in ext4_ext_split()->memset() if we read stale data from the newly allocated extent block on disk which has been failed to async write out but miss verify again since the verified bit has already been set on the buffer. [ 29.774674] BUG: unable to handle kernel paging request at ffff88841949d000 ... [ 29.783317] Oops: 0002 [#2] SMP [ 29.784219] R10: 00000000000f4240 R11: 0000000000002e28 R12: ffff88842fa1c800 [ 29.784627] CPU: 1 PID: 126 Comm: kworker/u4:3 Tainted: G D W [ 29.785546] R13: ffffffff9cddcc20 R14: ffffffff9cddd420 R15: ffff88842fa1c2f8 [ 29.786679] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),BIOS ?-20190727_0738364 [ 29.787588] FS: 0000000000000000(0000) GS:ffff88842fa00000(0000) knlGS:0000000000000000 [ 29.789288] Workqueue: writeback wb_workfn [ 29.790319] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.790321] (flush-8:0) [ 29.790844] CR2: 0000000000000008 CR3: 00000004234f2000 CR4: 00000000000006f0 [ 29.791924] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.792839] RIP: 0010:__memset+0x24/0x30 [ 29.793739] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.794256] Code: 90 90 90 90 90 90 0f 1f 44 00 00 49 89 f9 48 89 d1 83 e2 07 48 c1 e9 033 [ 29.795161] Kernel panic - not syncing: Fatal exception in interrupt ... [ 29.808149] Call Trace: [ 29.808475] ext4_ext_insert_extent+0x102e/0x1be0 [ 29.809085] ext4_ext_map_blocks+0xa89/0x1bb0 [ 29.809652] ext4_map_blocks+0x290/0x8a0 [ 29.809085] ext4_ext_map_blocks+0xa89/0x1bb0 [ 29.809652] ext4_map_blocks+0x290/0x8a0 [ 29.810161] ext4_writepages+0xc85/0x17c0 ... Fix this by clearing buffer's verified bit if we read meta block from disk again. Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200924073337.861472-2-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* | ext4: use fscrypt_prepare_new_inode() and fscrypt_set_context()Eric Biggers2020-09-221-20/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | Convert ext4 to use the new functions fscrypt_prepare_new_inode() and fscrypt_set_context(). This avoids calling fscrypt_get_encryption_info() from within a transaction, which can deadlock because fscrypt_get_encryption_info() isn't GFP_NOFS-safe. For more details about this problem, see the earlier patch "fscrypt: add fscrypt_prepare_new_inode() and fscrypt_set_context()". Link: https://lore.kernel.org/r/20200917041136.178600-4-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
* | ext4: factor out ext4_xattr_credits_for_new_inode()Eric Biggers2020-09-221-39/+51
|/ | | | | | | | | | | | | | To compute a new inode's xattr credits, we need to know whether the inode will be encrypted or not. When we switch to use the new helper function fscrypt_prepare_new_inode(), we won't find out whether the inode will be encrypted until slightly later than is currently the case. That will require moving the code block that computes the xattr credits. To make this easier and reduce the length of __ext4_new_inode(), move this code block into a new function ext4_xattr_credits_for_new_inode(). Link: https://lore.kernel.org/r/20200917041136.178600-3-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
* Merge tag 'ext4-for-linus-5.8-rc1-2' of ↵Linus Torvalds2020-06-151-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull more ext4 updates from Ted Ts'o: "This is the second round of ext4 commits for 5.8 merge window [1]. It includes the per-inode DAX support, which was dependant on the DAX infrastructure which came in via the XFS tree, and a number of regression and bug fixes; most notably the "BUG: using smp_processor_id() in preemptible code in ext4_mb_new_blocks" reported by syzkaller" [1] The pull request actually came in 15 minutes after I had tagged the rc1 release. Tssk, tssk, late.. - Linus * tag 'ext4-for-linus-5.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4, jbd2: ensure panic by fix a race between jbd2 abort and ext4 error handlers ext4: support xattr gnu.* namespace for the Hurd ext4: mballoc: Use this_cpu_read instead of this_cpu_ptr ext4: avoid utf8_strncasecmp() with unstable name ext4: stop overwrite the errcode in ext4_setup_super ext4: fix partial cluster initialization when splitting extent ext4: avoid race conditions when remounting with options that change dax Documentation/dax: Update DAX enablement for ext4 fs/ext4: Introduce DAX inode flag fs/ext4: Remove jflag variable fs/ext4: Make DAX mount option a tri-state fs/ext4: Only change S_DAX on inode load fs/ext4: Update ext4_should_use_dax() fs/ext4: Change EXT4_MOUNT_DAX to EXT4_MOUNT_DAX_ALWAYS fs/ext4: Disallow verity if inode is DAX fs/ext4: Narrow scope of DAX check in setflags
| * Enable ext4 support for per-file/directory dax operationsTheodore Ts'o2020-06-111-1/+1
| |\ | | | | | | | | | | | | | | | This adds the same per-file/per-directory DAX support for ext4 as was done for xfs, now that we finally have consensus over what the interface should be.
| | * fs/ext4: Only change S_DAX on inode loadIra Weiny2020-05-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To prevent complications with in memory inodes we only set S_DAX on inode load. FS_XFLAG_DAX can be changed at any time and S_DAX will change after inode eviction and reload. Add init bool to ext4_set_inode_flags() to indicate if the inode is being newly initialized. Assert that S_DAX is not set on an inode which is just being loaded. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20200528150003.828793-6-ira.weiny@intel.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* | | Merge tag 'ext4_for_linus' of ↵Linus Torvalds2020-06-051-0/+1
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: "A lot of bug fixes and cleanups for ext4, including: - Fix performance problems found in dioread_nolock now that it is the default, caused by transaction leaks. - Clean up fiemap handling in ext4 - Clean up and refactor multiple block allocator (mballoc) code - Fix a problem with mballoc with a smaller file systems running out of blocks because they couldn't properly use blocks that had been reserved by inode preallocation. - Fixed a race in ext4_sync_parent() versus rename() - Simplify the error handling in the extent manipulation code - Make sure all metadata I/O errors are felected to ext4_ext_dirty()'s and ext4_make_inode_dirty()'s callers. - Avoid passing an error pointer to brelse in ext4_xattr_set() - Fix race which could result to freeing an inode on the dirty last in data=journal mode. - Fix refcount handling if ext4_iget() fails - Fix a crash in generic/019 caused by a corrupted extent node" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (58 commits) ext4: avoid unnecessary transaction starts during writeback ext4: don't block for O_DIRECT if IOCB_NOWAIT is set ext4: remove the access_ok() check in ext4_ioctl_get_es_cache fs: remove the access_ok() check in ioctl_fiemap fs: handle FIEMAP_FLAG_SYNC in fiemap_prep fs: move fiemap range validation into the file systems instances iomap: fix the iomap_fiemap prototype fs: move the fiemap definitions out of fs.h fs: mark __generic_block_fiemap static ext4: remove the call to fiemap_check_flags in ext4_fiemap ext4: split _ext4_fiemap ext4: fix fiemap size checks for bitmap files ext4: fix EXT4_MAX_LOGICAL_BLOCK macro add comment for ext4_dir_entry_2 file_type member jbd2: avoid leaking transaction credits when unreserving handle ext4: drop ext4_journal_free_reserved() ext4: mballoc: use lock for checking free blocks while retrying ext4: mballoc: refactor ext4_mb_good_group() ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling ext4: mballoc: refactor ext4_mb_discard_preallocations() ...
| * | ext4: fix buffer_head refcnt leak when ext4_iget() failsXiyu Yang2020-06-031-0/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ext4_orphan_get() invokes ext4_read_inode_bitmap(), which returns a reference of the specified buffer_head object to "bitmap_bh" with increased refcnt. When ext4_orphan_get() returns, local variable "bitmap_bh" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in one exception handling path of ext4_orphan_get(). When ext4_iget() fails, the function forgets to decrease the refcnt increased by ext4_read_inode_bitmap(), causing a refcnt leak. Fix this issue by calling brelse() when ext4_iget() fails. Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Cc: stable@kernel.org Link: https://lore.kernel.org/r/1587618568-13418-1-git-send-email-xiyuyang19@fudan.edu.cn Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* / block: remove the error_sector argument to blkdev_issue_flushChristoph Hellwig2020-05-221-1/+1
|/ | | | | | | | The argument isn't used by any caller, and drivers don't fill out bi_sector for flush requests either. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* ext4: increase wait time needed before reuse of deleted inode numbersTheodore Ts'o2020-04-151-1/+1
| | | | | | | | | | | | | Current wait times have proven to be too short to protect against inode reuses that lead to metadata inconsistencies. Now that we will retry the inode allocation if we can't find any recently deleted inodes, it's a lot safer to increase the recently deleted time from 5 seconds to a minute. Link: https://lore.kernel.org/r/20200414023925.273867-1-tytso@mit.edu Google-Bug-Id: 36602237 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: fix return-value types in several function commentsJosh Triplett2020-04-151-1/+1
| | | | | | | | | | | | | | | The documentation comments for ext4_read_block_bitmap_nowait and ext4_read_inode_bitmap describe them as returning NULL on error, but they return an ERR_PTR on error; update the documentation to match. The documentation comment for ext4_wait_block_bitmap describes it as returning 1 on error, but it returns -errno on error; update the documentation to match. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Ritesh Harani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/60a3f4996f4932c45515aaa6b75ca42f2a78ec9b.1585512514.git.josh@joshtriplett.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: save all error info in save_error_info() and drop ext4_set_errno()Theodore Ts'o2020-04-011-7/+6
| | | | | | | | | | | | Using a separate function, ext4_set_errno() to set the errno is problematic because it doesn't do the right thing once s_last_error_errorcode is non-zero. It's also less racy to set all of the error information all at once. (Also, as a bonus, it shrinks code size slightly.) Link: https://lore.kernel.org/r/20200329020404.686965-1-tytso@mit.edu Fixes: 878520ac45f9 ("ext4: save the error code which triggered...") Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: avoid ENOSPC when avoiding to reuse recently deleted inodesJan Kara2020-03-261-5/+18
| | | | | | | | | | | | | | | | When ext4 is running on a filesystem without a journal, it tries not to reuse recently deleted inodes to provide better chances for filesystem recovery in case of crash. However this logic forbids reuse of freed inodes for up to 5 minutes and especially for filesystems with smaller number of inodes can lead to ENOSPC errors returned when allocating new inodes. Fix the problem by allowing to reuse recently deleted inode if there's no other inode free in the scanned range. Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200318121317.31941-1-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: fix potential race between s_flex_groups online resizing and accessSuraj Jitindar Singh2020-02-211-9/+14
| | | | | | | | | | | | | | | | | | | | During an online resize an array of s_flex_groups structures gets replaced so it can get enlarged. If there is a concurrent access to the array and this memory has been reused then this can lead to an invalid memory access. The s_flex_group array has been converted into an array of pointers rather than an array of structures. This is to ensure that the information contained in the structures cannot get out of sync during a resize due to an accessor updating the value in the old structure after it has been copied but before the array pointer is updated. Since the structures them- selves are no longer copied but only the pointers to them this case is mitigated. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206443 Link: https://lore.kernel.org/r/20200221053458.730016-4-tytso@mit.edu Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
* ext4: simulate various I/O and checksum errors when reading metadataTheodore Ts'o2019-12-261-1/+3
| | | | | | | This allows us to test various error handling code paths Link: https://lore.kernel.org/r/20191209012317.59398-1-tytso@mit.edu Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: save the error code which triggered an ext4_error() in the superblockTheodore Ts'o2019-12-261-0/+2
| | | | | | | | | | | This allows the cause of an ext4_error() report to be categorized based on whether it was triggered due to an I/O error, or an memory allocation error, or other possible causes. Most errors are caused by a detected file system inconsistency, so the default code stored in the superblock will be EXT4_ERR_EFSCORRUPTED. Link: https://lore.kernel.org/r/20191204032335.7683-1-tytso@mit.edu Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: reserve revoke credits in __ext4_new_inodeyangerkun2019-12-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's possible that __ext4_new_inode will release the xattr block, so it will trigger a warning since there is revoke credits will be 0 if the handle == NULL. The below scripts can reproduce it easily. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 3861 at fs/jbd2/revoke.c:374 jbd2_journal_revoke+0x30e/0x540 fs/jbd2/revoke.c:374 ... __ext4_forget+0x1d7/0x800 fs/ext4/ext4_jbd2.c:248 ext4_free_blocks+0x213/0x1d60 fs/ext4/mballoc.c:4743 ext4_xattr_release_block+0x55b/0x780 fs/ext4/xattr.c:1254 ext4_xattr_block_set+0x1c2c/0x2c40 fs/ext4/xattr.c:2112 ext4_xattr_set_handle+0xa7e/0x1090 fs/ext4/xattr.c:2384 __ext4_set_acl+0x54d/0x6c0 fs/ext4/acl.c:214 ext4_init_acl+0x218/0x2e0 fs/ext4/acl.c:293 __ext4_new_inode+0x352a/0x42b0 fs/ext4/ialloc.c:1151 ext4_mkdir+0x2e9/0xbd0 fs/ext4/namei.c:2774 vfs_mkdir+0x386/0x5f0 fs/namei.c:3811 do_mkdirat+0x11c/0x210 fs/namei.c:3834 do_syscall_64+0xa1/0x530 arch/x86/entry/common.c:294 ... ------------------------------------- scripts: mkfs.ext4 /dev/vdb mount /dev/vdb /mnt cd /mnt && mkdir dir && for i in {1..8}; do setfacl -dm "u:user_"$i":rx" dir; done mkdir dir/dir1 && mv dir/dir1 ./ sh repro.sh && add some user [root@localhost ~]# cat repro.sh while [ 1 -eq 1 ]; do rm -rf dir rm -rf dir1/dir1 mkdir dir for i in {1..8}; do setfacl -dm "u:test"$i":rx" dir; done setfacl -m "u:user_9:rx" dir & mkdir dir1/dir1 & done Before exec repro.sh, dir1 has inherit the default acl from dir, and xattr block of dir1 dir is not the same, so the h_refcount of these two dir's xattr block will be 1. Then repro.sh can trigger the warning with the situation show as below. The last h_refcount can be clear with mkdir, and __ext4_new_inode has not reserved revoke credits, so the warning will happened, fix it by reserve revoke credits in __ext4_new_inode. Thread 1 Thread 2 mkdir dir set default acl(will create a xattr block blk1 and the refcount of ext4_xattr_header will be 1) ... mkdir dir1/dir1 ->....->ext4_init_acl ->__ext4_set_acl(set default acl, will reuse blk1, and h_refcount will be 2) setfacl->ext4_set_acl->... ->ext4_xattr_block_set(will create new block blk2 to store xattr) ->__ext4_set_acl(set access acl, since h_refcount of blk1 is 2, will create blk3 to store xattr) ->ext4_xattr_release_block(dec h_refcount of blk1 to 1) ->ext4_xattr_release_block(dec h_refcount and since it is 0, will release the block and trigger the warning) Link: https://lore.kernel.org/r/20191213014900.47228-1-yangerkun@huawei.com Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: yangerkun <yangerkun@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: fix leak of quota reservationsJan Kara2019-11-141-5/+0
| | | | | | | | | | | | | | | | | | Commit 8fcc3a580651 ("ext4: rework reserved cluster accounting when invalidating pages") moved freeing of delayed allocation reservations from dirty page invalidation time to time when we evict corresponding status extent from extent status tree. For inodes which don't have any blocks allocated this may actually happen only in ext4_clear_blocks() which is after we've dropped references to quota structures from the inode. Thus reservation of quota leaked. Fix the problem by clearing quota information from the inode only after evicting extent status tree in ext4_clear_inode(). Link: https://lore.kernel.org/r/20191108115420.GI20863@quack2.suse.cz Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Fixes: 8fcc3a580651 ("ext4: rework reserved cluster accounting when invalidating pages") Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: Reserve revoke credits for freed blocksJan Kara2019-11-051-1/+1
| | | | | | | | | | | | | | | | | | So far we have reserved only relatively high fixed amount of revoke credits for each transaction. We over-reserved by large amount for most cases but when freeing large directories or files with data journalling, the fixed amount is not enough. In fact the worst case estimate is inconveniently large (maximum extent size) for freeing of one extent. We fix this by doing proper estimate of the amount of blocks that need to be revoked when removing blocks from the inode due to truncate or hole punching and otherwise reserve just a small amount of revoke credits for each transaction to accommodate freeing of xattrs block or so. Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20191105164437.32602-23-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: Support case-insensitive file name lookupsGabriel Krisman Bertazi2019-04-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements the actual support for case-insensitive file name lookups in ext4, based on the feature bit and the encoding stored in the superblock. A filesystem that has the casefold feature set is able to configure directories with the +F (EXT4_CASEFOLD_FL) attribute, enabling lookups to succeed in that directory in a case-insensitive fashion, i.e: match a directory entry even if the name used by userspace is not a byte per byte match with the disk name, but is an equivalent case-insensitive version of the Unicode string. This operation is called a case-insensitive file name lookup. The feature is configured as an inode attribute applied to directories and inherited by its children. This attribute can only be enabled on empty directories for filesystems that support the encoding feature, thus preventing collision of file names that only differ by case. * dcache handling: For a +F directory, Ext4 only stores the first equivalent name dentry used in the dcache. This is done to prevent unintentional duplication of dentries in the dcache, while also allowing the VFS code to quickly find the right entry in the cache despite which equivalent string was used in a previous lookup, without having to resort to ->lookup(). d_hash() of casefolded directories is implemented as the hash of the casefolded string, such that we always have a well-known bucket for all the equivalencies of the same string. d_compare() uses the utf8_strncasecmp() infrastructure, which handles the comparison of equivalent, same case, names as well. For now, negative lookups are not inserted in the dcache, since they would need to be invalidated anyway, because we can't trust missing file dentries. This is bad for performance but requires some leveraging of the vfs layer to fix. We can live without that for now, and so does everyone else. * on-disk data: Despite using a specific version of the name as the internal representation within the dcache, the name stored and fetched from the disk is a byte-per-byte match with what the user requested, making this implementation 'name-preserving'. i.e. no actual information is lost when writing to storage. DX is supported by modifying the hashes used in +F directories to make them case/encoding-aware. The new disk hashes are calculated as the hash of the full casefolded string, instead of the string directly. This allows us to efficiently search for file names in the htree without requiring the user to provide an exact name. * Dealing with invalid sequences: By default, when a invalid UTF-8 sequence is identified, ext4 will treat it as an opaque byte sequence, ignoring the encoding and reverting to the old behavior for that unique file. This means that case-insensitive file name lookup will not work only for that file. An optional bit can be set in the superblock telling the filesystem code and userspace tools to enforce the encoding. When that optional bit is set, any attempt to create a file name using an invalid UTF-8 sequence will fail and return an error to userspace. * Normalization algorithm: The UTF-8 algorithms used to compare strings in ext4 is implemented lives in fs/unicode, and is based on a previous version developed by SGI. It implements the Canonical decomposition (NFD) algorithm described by the Unicode specification 12.1, or higher, combined with the elimination of ignorable code points (NFDi) and full case-folding (CF) as documented in fs/unicode/utf8_norm.c. NFD seems to be the best normalization method for EXT4 because: - It has a lower cost than NFC/NFKC (which requires decomposing to NFD as an intermediary step) - It doesn't eliminate important semantic meaning like compatibility decompositions. Although: - This implementation is not completely linguistic accurate, because different languages have conflicting rules, which would require the specialization of the filesystem to a given locale, which brings all sorts of problems for removable media and for users who use more than one language. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: use IS_ENCRYPTED() to check encryption statusChandan Rajendra2019-01-231-1/+1
| | | | | | | | | | This commit removes the ext4 specific ext4_encrypted_inode() and makes use of the generic IS_ENCRYPTED() macro to check for the encryption status of an inode. Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com>
* ext4: avoid declaring fs inconsistent due to invalid file handlesTheodore Ts'o2018-12-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we receive a file handle, either from NFS or open_by_handle_at(2), and it points at an inode which has not been initialized, and the file system has metadata checksums enabled, we shouldn't try to get the inode, discover the checksum is invalid, and then declare the file system as being inconsistent. This can be reproduced by creating a test file system via "mke2fs -t ext4 -O metadata_csum /tmp/foo.img 8M", mounting it, cd'ing into that directory, and then running the following program. #define _GNU_SOURCE #include <fcntl.h> struct handle { struct file_handle fh; unsigned char fid[MAX_HANDLE_SZ]; }; int main(int argc, char **argv) { struct handle h = {{8, 1 }, { 12, }}; open_by_handle_at(AT_FDCWD, &h.fh, O_RDONLY); return 0; } Google-Bug-Id: 120690101 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
* ext4: don't open-code ERR_CASTAl Viro2018-10-101-1/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ext4: use ext4_warning() for sb_getblk failureWang Shilong2018-08-011-3/+3
| | | | | | | | | Out of memory should not be considered as critical errors; so replace ext4_error() with ext4_warnig(). Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org