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5 daysMerge tag 'pull-configfs-fixed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull configfs updates from Al Viro: "A couple of fixes (UAF in configfs_lookup() and really old races introduced when lseek() on configfs directories stopped locking those directories; impact up to and including UAF). Fixes aside, the main result is that configfs is finally switched to tree-in-dcache machinery. It's *not* making use of recursive removal helpers yet, and it still does the bloody awful "build subtree in full sight of userland, with possibility of failure halfway through and need to unroll" that forces the locking model from hell; dealing with that is a separate patch series, once this one is out of the way. However, it is using DCACHE_PERSISTENT properly now. And apparmorfs is the sole remaining user of __simple_{unlink,rmdir}() at that point" * tag 'pull-configfs-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: create_default_group(): pass parent's dentry instead of config_group configfs_attach_group(): drop the unused parent_item argument configs_attach_item(): drop unused parent_item argument configfs_create(): lift parent timestamp updates into callers kill configfs_drop_dentry() configfs: mark pinned dentries persistent configfs: dentry refcount needs to be pinned only once switch configfs_detach_{group,item}() to passing dentry configfs_remove_dir(), detach_attrs(): switch to passing dentry populate_attrs(): move cleanup to the sole caller populate_group(): move cleanup on failure to the sole caller configfs_detach_rollback(): pass configfs_dirent instead of dentry configfs_do_depend_item(): pass configfs_dirent instead of dentry configfs_depend_prep(): pass configfs_dirent instead of dentry configfs_detach_prep(): pass configfs_dirent instead of dentry configfs_mkdir(): use take_dentry_name_snapshot() configfs: fix lockless traversals of ->s_children configfs_lookup(): don't leave ->s_dentry dangling on failure
5 daysMerge tag 'pull-d_add' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds
Pull dentry d_add() cleanups from Al Viro: "This converts a bunch of unidiomatic uses of d_add() in ->lookup() instances to equivalent uses of d_splice_alias(), which is the normal mechanism for ->lookup()" * tag 'pull-d_add' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: gfs2: use d_splice_alias() for ->lookup() return value ntfs: use d_splice_alias() for ->lookup() return value simple_lookup(): use d_splice_alias() for ->lookup() return value ecryptfs: use d_splice_alias() for ->lookup() return value configfs_lookup(): switch to d_splice_alias() tracefs: use d_splice_alias() in ->lookup() instances
11 dayscreate_default_group(): pass parent's dentry instead of config_groupAl Viro
the only way parent_group is used there... Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysconfigfs_attach_group(): drop the unused parent_item argumentAl Viro
This one *was* used - for passing it to configfs_attach_item(), which didn't use the value passed to it. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysconfigs_attach_item(): drop unused parent_item argumentAl Viro
That argument has been unused since the initial merge in 2005. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysconfigfs_create(): lift parent timestamp updates into callersAl Viro
... and do *not* do it in ->lookup() case. stat foo/bar should not update mtime of foo, TYVM... Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 dayskill configfs_drop_dentry()Al Viro
Fold into the only remaining user, don't bother with the timestamps of parent - we are going to rmdir it shortly anyway, which will override those. Fix the locking of inode, while we are at it - updating the link count and timestamps ought to be done with the inode locked. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysconfigfs: mark pinned dentries persistentAl Viro
on the removal side we can (finally) get rid of __simple_unlink() and __simple_rmdir() kludges now that dentries in question are properly marked persistent - simple_unlink() and simple_rmdir() will do the right thing for those. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysconfigfs: dentry refcount needs to be pinned only onceAl Viro
currently we have a weird situation where * symlinks and roots of subtrees created by mkdir are pinned once * subdirectories of subtrees created by mkdir are pinned twice * roots of subtrees created by register_{group,subsystem} are pinned twice. It makes things harder to follow for no good reason. The goal is to encapsulate the unbalanced dget/dput into d_{make,discard}_persisitent() and, preferably, allow a use of simple_recursive_removal() or analogue thereof. So let's regularize that and pin things only once. create_default_group() and configfs_register_subsystem() don't need to keep their reference around on success - configfs_create_dir() has pinned the sucker already. So we can drop the reference passed to configfs_create_dir() (via configfs_attach_group(), etc.) both on success and on failure. On the removal side we no longer have the double references, so we need an explicit dget() to compensate. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysswitch configfs_detach_{group,item}() to passing dentryAl Viro
... and there's no need to grab/drop it, or check for NULL - none of the callers would even get there with NULL dentry and all of them have the sucker pinned Note that if sd is a directory configfs_dirent, we have sd->s_element pointing to config_item with item->ci_dentry equal to sd->s_dentry. Which is the only reason why detach_groups() gets away with using the latter for locking the inode and the former for removal. Aren't redundant data structures wonderful, for obfuscation if nothing else? Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysconfigfs_remove_dir(), detach_attrs(): switch to passing dentryAl Viro
... and deal with grabbing/dropping it in the sole caller. After that configfs_remove_dir() becomes an unconditional call of remove_dir(), so we can fold them together. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 dayspopulate_attrs(): move cleanup to the sole callerAl Viro
... where it folds with configfs_remove_dir() into a call of configfs_detach_item(). Note that at the early failure exit (before we'd added any children) we were not calling detach_attrs() only because there it would've been a no-op - nothing added, nothing there to be removed. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 dayspopulate_group(): move cleanup on failure to the sole callerAl Viro
... where it folds with configfs_detach_item() into a call of configfs_detach_group(). Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysconfigfs_detach_rollback(): pass configfs_dirent instead of dentryAl Viro
same story as with configfs_detach_prep() this function is undoing. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysconfigfs_do_depend_item(): pass configfs_dirent instead of dentryAl Viro
Again, the only thing it uses the argument for is its ->d_fsdata and callers already have that - as the matter of fact, they are passing ->s_dentry of that configfs_dirent, so that the function could get it back as ->d_fsdata of that. With nothing else in dentry even looked at... configfs_dirent in question is a directory one - in this case those are subdirectories of root (aka roots of "subsystem" trees). Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysconfigfs_depend_prep(): pass configfs_dirent instead of dentryAl Viro
Again, the only thing it uses dentry for is dentry->d_fsdata; for the recursive call the situation is the same as with configfs_detach_prep() and the same observation about ->s_dentry->d_fsdata applies. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysconfigfs_detach_prep(): pass configfs_dirent instead of dentryAl Viro
The only thing it uses the argument for is its ->d_fsdata and all callers have that already available. Note that in the recursive call we are dealing with a (sub)directory configfs_dirent, and for those ->s_dentry->d_fsdata points back to configfs_dirent itself. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysconfigfs_mkdir(): use take_dentry_name_snapshot()Al Viro
Note that neither ->make_group() nor ->make_item() are allowed to modify the string passed to them - the argument is const char *. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
11 daysconfigfs: fix lockless traversals of ->s_childrenAl Viro
Having the parent directory locked protects entries from removal by another thread, but it does *not* protect cursors from being moved around by lseek() - or freed, for that matter. Fixes: 6f6107640625 ("configfs: Introduce configfs_dirent_lock") Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2026-06-05configfs_lookup(): switch to d_splice_alias()Al Viro
more idiomatic Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2026-06-03configfs_lookup(): don't leave ->s_dentry dangling on failureAl Viro
Normally ->s_dentry is cleared when dentry it's pointing to becomes negative (on eviction, realistically). However, that only happens if dentry gets to be positive in the first place; in case of inode allocation failure dentry never becomes positive, so ->d_iput() is not called at all. We do part of what normally would've been done by configfs_d_iput() (dropping the reference to configfs_dirent) manually, but we do not clear ->s_dentry there. Sloppy as it is, it does not matter in case of configfs_create_{dir,link}() - there configfs_dirent does not survive dropping the sole reference to it. However, for configfs_lookup() it *does* survive, with a dangling pointer to soon to be freed dentry sitting it its ->s_dentry. Subsequent getdents(2) in that directory will end up dereferencing that pointer in order to pick the inode number. Use after free... This is the minimal fix; the right approach is to set the linkage between dentry and configfs_dirent only after we know that we have an inode, but that takes more surgery and the bug had been there since 2006, so... Fixes: 3d0f89bb1694 ("configfs: Add permission and ownership to configfs objects") # 2.6.16-rc3 Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2026-05-28configfs: replace __get_free_pages() with kzalloc()Mike Rapoport (Microsoft)
configfs allocates staging buffers __get_free_pages(). kmalloc() is a better API for such use and it also provides better scalability and more debugging possibilities. Replace use of __get_free_pages() with kzalloc(). Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Link: https://patch.msgid.link/20260523-b4-fs-v1-15-275e36a83f0e@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2025-12-05Merge tag 'pull-persistency' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull persistent dentry infrastructure and conversion from Al Viro: "Some filesystems use a kinda-sorta controlled dentry refcount leak to pin dentries of created objects in dcache (and undo it when removing those). A reference is grabbed and not released, but it's not actually _stored_ anywhere. That works, but it's hard to follow and verify; among other things, we have no way to tell _which_ of the increments is intended to be an unpaired one. Worse, on removal we need to decide whether the reference had already been dropped, which can be non-trivial if that removal is on umount and we need to figure out if this dentry is pinned due to e.g. unlink() not done. Usually that is handled by using kill_litter_super() as ->kill_sb(), but there are open-coded special cases of the same (consider e.g. /proc/self). Things get simpler if we introduce a new dentry flag (DCACHE_PERSISTENT) marking those "leaked" dentries. Having it set claims responsibility for +1 in refcount. The end result this series is aiming for: - get these unbalanced dget() and dput() replaced with new primitives that would, in addition to adjusting refcount, set and clear persistency flag. - instead of having kill_litter_super() mess with removing the remaining "leaked" references (e.g. for all tmpfs files that hadn't been removed prior to umount), have the regular shrink_dcache_for_umount() strip DCACHE_PERSISTENT of all dentries, dropping the corresponding reference if it had been set. After that kill_litter_super() becomes an equivalent of kill_anon_super(). Doing that in a single step is not feasible - it would affect too many places in too many filesystems. It has to be split into a series. This work has really started early in 2024; quite a few preliminary pieces have already gone into mainline. This chunk is finally getting to the meat of that stuff - infrastructure and most of the conversions to it. Some pieces are still sitting in the local branches, but the bulk of that stuff is here" * tag 'pull-persistency' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits) d_make_discardable(): warn if given a non-persistent dentry kill securityfs_recursive_remove() convert securityfs get rid of kill_litter_super() convert rust_binderfs convert nfsctl convert rpc_pipefs convert hypfs hypfs: swich hypfs_create_u64() to returning int hypfs: switch hypfs_create_str() to returning int hypfs: don't pin dentries twice convert gadgetfs gadgetfs: switch to simple_remove_by_name() convert functionfs functionfs: switch to simple_remove_by_name() functionfs: fix the open/removal races functionfs: need to cancel ->reset_work in ->kill_sb() functionfs: don't bother with ffs->ref in ffs_data_{opened,closed}() functionfs: don't abuse ffs_data_closed() on fs shutdown convert selinuxfs ...
2025-11-27configfs: Constify ct_item_ops in struct config_item_typeChristophe JAILLET
Make 'ct_item_ops' const in struct config_item_type. This allows constification of many structures which hold some function pointers. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/f43cb57418a7f59e883be8eedc7d6abe802a2094.1761390472.git.christophe.jaillet@wanadoo.fr Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
2025-11-27configfs: Constify ct_group_ops in struct config_item_typeChristophe JAILLET
Make 'ct_group_ops' const in struct config_item_type. This allows constification of many structures which hold some function pointers. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/6b720cf407e8a6d30f35beb72e031b2553d1ab7e.1761390472.git.christophe.jaillet@wanadoo.fr Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
2025-11-17d_make_discardable(): warn if given a non-persistent dentryAl Viro
At this point there are very few call chains that might lead to d_make_discardable() on a dentry that hadn't been made persistent: calls of simple_unlink() and simple_rmdir() in configfs and apparmorfs. Both filesystems do pin (part of) their contents in dcache, but they are currently playing very unusual games with that. Converting them to more usual patterns might be possible, but it's definitely going to be a long series of changes in both cases. For now the easiest solution is to have both stop using simple_unlink() and simple_rmdir() - that allows to make d_make_discardable() warn when given a non-persistent dentry. Rather than giving them full-blown private copies (with calls of d_make_discardable() replaced with dput()), let's pull the parts of simple_unlink() and simple_rmdir() that deal with timestamps and link counts into separate helpers (__simple_unlink() and __simple_rmdir() resp.) and have those used by configfs and apparmorfs. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-11-16configfs, securityfs: kill_litter_super() not neededAl Viro
These are guaranteed to be empty by the time they are shut down; both are single-instance and there is an internal mount maintained for as long as there is any contents. Both have that internal mount pinned by every object in root. In other words, kill_litter_super() boils down to kill_anon_super() for those. Reviewed-by: Joel Becker <jlbec@evilplan.org> Acked-by: Paul Moore <paul@paul-moore> (LSM) Acked-by: Andreas Hindborg <a.hindborg@kernel.org> (configfs) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-10-03Merge tag 'pull-f_path' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull file->f_path constification from Al Viro: "Only one thing was modifying ->f_path of an opened file - acct(2). Massaging that away and constifying a bunch of struct path * arguments in functions that might be given &file->f_path ends up with the situation where we can turn ->f_path into an anon union of const struct path f_path and struct path __f_path, the latter modified only in a few places in fs/{file_table,open,namei}.c, all for struct file instances that are yet to be opened" * tag 'pull-f_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (23 commits) Have cc(1) catch attempts to modify ->f_path kernel/acct.c: saner struct file treatment configfs:get_target() - release path as soon as we grab configfs_item reference apparmor/af_unix: constify struct path * arguments ovl_is_real_file: constify realpath argument ovl_sync_file(): constify path argument ovl_lower_dir(): constify path argument ovl_get_verity_digest(): constify path argument ovl_validate_verity(): constify {meta,data}path arguments ovl_ensure_verity_loaded(): constify datapath argument ksmbd_vfs_set_init_posix_acl(): constify path argument ksmbd_vfs_inherit_posix_acl(): constify path argument ksmbd_vfs_kern_path_unlock(): constify path argument ksmbd_vfs_path_lookup_locked(): root_share_path can be const struct path * check_export(): constify path argument export_operations->open(): constify path argument rqst_exp_get_by_name(): constify path argument nfs: constify path argument of __vfs_getattr() bpf...d_path(): constify path argument done_path_create(): constify path argument ...
2025-10-03Merge tag 'configfs-for-v6.18' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/a.hindborg/linux Pull configfs update from Andreas Hindborg: "Just a very small refactoring to use PTR_ERR_OR_ZERO()" * tag 'configfs-for-v6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/a.hindborg/linux: configfs: use PTR_ERR_OR_ZERO() to simplify code
2025-09-15configfs:get_target() - release path as soon as we grab configfs_item referenceAl Viro
... and get rid of path argument - it turns into a local variable in get_target() Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-09-15fs: rename generic_delete_inode() and generic_drop_inode()Mateusz Guzik
generic_delete_inode() is rather misleading for what the routine is doing. inode_just_drop() should be much clearer. The new naming is inconsistent with generic_drop_inode(), so rename that one as well with inode_ as the suffix. No functional changes. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-04configfs: use PTR_ERR_OR_ZERO() to simplify codeXichao Zhao
Use the standard error pointer macro to shorten the code and simplify. Signed-off-by: Xichao Zhao <zhao.xichao@vivo.com> Reviewed-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20250812082709.49796-1-zhao.xichao@vivo.com Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
2025-06-11configfs: use DCACHE_DONTCACHEAl Viro
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-06-10new helper: set_default_d_op()Al Viro
... to be used instead of manually assigning to ->s_d_op. All in-tree filesystem converted (and field itself is renamed, so any out-of-tree ones in need of conversion will be caught by compiler). Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-05-31Merge tag 'mm-nonmm-stable-2025-05-31-15-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "hung_task: extend blocking task stacktrace dump to semaphore" from Lance Yang enhances the hung task detector. The detector presently dumps the blocking tasks's stack when it is blocked on a mutex. Lance's series extends this to semaphores - "nilfs2: improve sanity checks in dirty state propagation" from Wentao Liang addresses a couple of minor flaws in nilfs2 - "scripts/gdb: Fixes related to lx_per_cpu()" from Illia Ostapyshyn fixes a couple of issues in the gdb scripts - "Support kdump with LUKS encryption by reusing LUKS volume keys" from Coiby Xu addresses a usability problem with kdump. When the dump device is LUKS-encrypted, the kdump kernel may not have the keys to the encrypted filesystem. A full writeup of this is in the series [0/N] cover letter - "sysfs: add counters for lockups and stalls" from Max Kellermann adds /sys/kernel/hardlockup_count and /sys/kernel/hardlockup_count and /sys/kernel/rcu_stall_count - "fork: Page operation cleanups in the fork code" from Pasha Tatashin implements a number of code cleanups in fork.c - "scripts/gdb/symbols: determine KASLR offset on s390 during early boot" from Ilya Leoshkevich fixes some s390 issues in the gdb scripts * tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (67 commits) llist: make llist_add_batch() a static inline delayacct: remove redundant code and adjust indentation squashfs: add optional full compressed block caching crash_dump, nvme: select CONFIGFS_FS as built-in scripts/gdb/symbols: determine KASLR offset on s390 during early boot scripts/gdb/symbols: factor out pagination_off() scripts/gdb/symbols: factor out get_vmlinux() kernel/panic.c: format kernel-doc comments mailmap: update and consolidate Casey Connolly's name and email nilfs2: remove wbc->for_reclaim handling fork: define a local GFP_VMAP_STACK fork: check charging success before zeroing stack fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code fork: clean-up ifdef logic around stack allocation kernel/rcu/tree_stall: add /sys/kernel/rcu_stall_count kernel/watchdog: add /sys/kernel/{hard,soft}lockup_count x86/crash: make the page that stores the dm crypt keys inaccessible x86/crash: pass dm crypt keys to kdump kernel Revert "x86/mm: Remove unused __set_memory_prot()" crash_dump: retrieve dm crypt keys in kdump kernel ...
2025-05-27crash_dump, nvme: select CONFIGFS_FS as built-inArnd Bergmann
Configfs can be configured as a loadable module, which causes a link-time failure for dm-crypt crash dump support: crash_dump_dm_crypt.c:(.text+0x3a4): undefined reference to `config_item_init_type_name' aarch64-linux-ld: kernel/crash_dump_dm_crypt.o: in function `configfs_dmcrypt_keys_init': crash_dump_dm_crypt.c:(.init.text+0x90): undefined reference to `config_group_init' aarch64-linux-ld: crash_dump_dm_crypt.c:(.init.text+0xb4): undefined reference to `configfs_register_subsystem' aarch64-linux-ld: crash_dump_dm_crypt.c:(.init.text+0xd8): undefined reference to `configfs_unregister_subsystem' This could be avoided with a dependency on CONFIGFS_FS=y, but the dependency has an additional problem of causing Kconfig dependency loops since most other uses select the symbol. Using a simple 'select CONFIGFS_FS' here in turn fails with CONFIG_DM_CRYPT=m, because that still only causes configfs to be a loadable module. The only version I found that fixes this reliably uses an additional Kconfig symbol to ensure the 'select' actually turns on configfs as builtin, with two additional changes to avoid dependency loops with nvme and sysfs. There is no compile-time dependency between configfs and sysfs, so selecting configfs from a driver with sysfs disabled does not cause link failures, only the default /sys/kernel/config mount point will not be created. Link: https://lkml.kernel.org/r/20250521160359.2132363-1-arnd@kernel.org Fixes: 6b23858fd63b ("crash_dump: make dm crypt keys persist for the kdump kernel") Fixes: 1fb470408497 ("nvme-loop: add configfs dependency") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Andreas Hindborg <a.hindborg@kernel.org> Cc: Breno Leitao <leitao@debian.org> Cc: Chaitanya Kulkarni <kch@nvidia.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Coiby Xu <coxu@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-09configfs: Correct error value returned by API config_item_set_name()Zijun Hu
kvasprintf() failure is often caused by memory allocation which has error code -ENOMEM, but config_item_set_name() returns -EFAULT for the failure. Fix by returning -ENOMEM instead of -EFAULT for the failure. Reviewed-by: Joel Becker <jlbec@evilplan.org> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20250507-fix_configfs-v3-3-fe2d96de8dc4@quicinc.com Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
2025-05-09configfs: Do not override creating attribute file failure in populate_attrs()Zijun Hu
populate_attrs() may override failure for creating attribute files by success for creating subsequent bin attribute files, and have wrong return value. Fix by creating bin attribute files under successfully creating attribute files. Fixes: 03607ace807b ("configfs: implement binary attributes") Cc: stable@vger.kernel.org Reviewed-by: Joel Becker <jlbec@evilplan.org> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20250507-fix_configfs-v3-2-fe2d96de8dc4@quicinc.com Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
2025-05-09configfs: Delete semicolon from macro type_print() definitionZijun Hu
Macro type_print() definition ends with semicolon, so will cause the subsequent macro invocations end with two semicolons. Fix by deleting the semicolon from the macro definition. Reviewed-by: Joel Becker <jlbec@evilplan.org> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20250507-fix_configfs-v3-1-fe2d96de8dc4@quicinc.com Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
2025-02-27Change inode_operations.mkdir to return struct dentry *NeilBrown
Some filesystems, such as NFS, cifs, ceph, and fuse, do not have complete control of sequencing on the actual filesystem (e.g. on a different server) and may find that the inode created for a mkdir request already exists in the icache and dcache by the time the mkdir request returns. For example, if the filesystem is mounted twice the directory could be visible on the other mount before it is on the original mount, and a pair of name_to_handle_at(), open_by_handle_at() calls could instantiate the directory inode with an IS_ROOT() dentry before the first mkdir returns. This means that the dentry passed to ->mkdir() may not be the one that is associated with the inode after the ->mkdir() completes. Some callers need to interact with the inode after the ->mkdir completes and they currently need to perform a lookup in the (rare) case that the dentry is no longer hashed. This lookup-after-mkdir requires that the directory remains locked to avoid races. Planned future patches to lock the dentry rather than the directory will mean that this lookup cannot be performed atomically with the mkdir. To remove this barrier, this patch changes ->mkdir to return the resulting dentry if it is different from the one passed in. Possible returns are: NULL - the directory was created and no other dentry was used ERR_PTR() - an error occurred non-NULL - this other dentry was spliced in This patch only changes file-systems to return "ERR_PTR(err)" instead of "err" or equivalent transformations. Subsequent patches will make further changes to some file-systems to return a correct dentry. Not all filesystems reliably result in a positive hashed dentry: - NFS, cifs, hostfs will sometimes need to perform a lookup of the name to get inode information. Races could result in this returning something different. Note that this lookup is non-atomic which is what we are trying to avoid. Placing the lookup in filesystem code means it only happens when the filesystem has no other option. - kernfs and tracefs leave the dentry negative and the ->revalidate operation ensures that lookup will be called to correctly populate the dentry. This could be fixed but I don't think it is important to any of the users of vfs_mkdir() which look at the dentry. The recommendation to use d_drop();d_splice_alias() is ugly but fits with current practice. A planned future patch will change this. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: NeilBrown <neilb@suse.de> Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-11-14configfs: improve item creation performanceSeamus Connor
As the size of a directory increases item creation slows down. Optimizing access to s_children removes this bottleneck. dirents are already pinned into the cache, there is no need to scan the s_children list looking for duplicate Items. The configfs_dirent_exists check is moved to a location where it is called only during subsystem initialization. d_lookup will only need to call configfs_lookup in the case where the item in question is not pinned to dcache. The only items not pinned to dcache are attributes. These are placed at the front of the s_children list, whilst pinned items are inserted at the back. configfs_lookup stops scanning when it encounters the first pinned entry in s_children. The assumption of the above optimizations is that there will be few attributes, but potentially many Items in a given directory. Signed-off-by: Seamus Connor <sconnor@purestorage.com> Reviewed-by: Joel Becker <jlbec@evilplan.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-11-14configfs: remove unused configfs_hash_and_removeDr. David Alan Gilbert
configfs_hash_and_remove() has been unused since it was added in 2005 by commit 7063fbf22611 ("[PATCH] configfs: User-driven configuration filesystem") Remove it. Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-06-17fs/configfs: Add a callback to determine attribute visibilityTom Lendacky
In order to support dynamic decisions as to whether an attribute should be created, add a callback that returns a bool to indicate whether the attribute should be displayed. If no callback is registered, the attribute is displayed by default. Co-developed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/e555c8740a263fab9f83b2cbb44da1af49a2813c.1717600736.git.thomas.lendacky@amd.com
2023-10-18configfs: convert to new timestamp accessorsJeff Layton
Convert to using the new inode timestamp accessor functions. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20231004185347.80880-24-jlayton@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-13configfs: convert to ctime accessor functionsJeff Layton
In later patches, we're going to change how the inode's ctime field is used. Switch to using accessor functions instead of raw accesses of inode->i_ctime. Signed-off-by: Jeff Layton <jlayton@kernel.org> Acked-by: Joel Becker <jlbec@evilplan.org> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230705190309.579783-30-jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-04-03fs: consolidate duplicate dt_type helpersJeff Layton
There are three copies of the same dt_type helper sprinkled around the tree. Convert them to use the common fs_umode_to_dtype function instead, which has the added advantage of properly returning DT_UNKNOWN when given a mode that contains an unrecognized type. Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Phillip Potter <phil@philpotter.co.uk> Suggested-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jeff Layton <jlayton@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Christian Brauner <brauner@kernel.org> Message-Id: <20230330104144.75547-1-jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-01-19fs: port ->permission() 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 ->mkdir() 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>