kernel/linux.git/include/linux/dcache.h, branch v6.0.14

Merge tag 'ceph-for-5.20-rc1' of https://github.com/ceph/ceph-client

2022-08-11T19:41:07+00:00

Pull ceph updates from Ilya Dryomov: "We have a good pile of various fixes and cleanups from Xiubo, Jeff, Luis and others, almost exclusively in the filesystem. Several patches touch files outside of our normal purview to set the stage for bringing in Jeff's long awaited ceph+fscrypt series in the near future. All of them have appropriate acks and sat in linux-next for a while" * tag 'ceph-for-5.20-rc1' of https://github.com/ceph/ceph-client: (27 commits) libceph: clean up ceph_osdc_start_request prototype libceph: fix ceph_pagelist_reserve() comment typo ceph: remove useless check for the folio ceph: don't truncate file in atomic_open ceph: make f_bsize always equal to f_frsize ceph: flush the dirty caps immediatelly when quota is approaching libceph: print fsid and epoch with osd id libceph: check pointer before assigned to "c->rules[]" ceph: don't get the inline data for new creating files ceph: update the auth cap when the async create req is forwarded ceph: make change_auth_cap_ses a global symbol ceph: fix incorrect old_size length in ceph_mds_request_args ceph: switch back to testing for NULL folio->private in ceph_dirty_folio ceph: call netfs_subreq_terminated with was_async == false ceph: convert to generic_file_llseek ceph: fix the incorrect comment for the ceph_mds_caps struct ceph: don't leak snap_rwsem in handle_cap_grant ceph: prevent a client from exceeding the MDS maximum xattr size ceph: choose auth MDS for getxattr with the Xs caps ceph: add session already open notify support ...

fs/dcache: export d_same_name() helper

2022-08-02T22:54:12+00:00

Compare dentry name with case-exact name, return true if names are same, or false. Signed-off-by: Xiubo Li Reviewed-by: Jeff Layton Reviewed-by: Luis Chamberlain Signed-off-by: Ilya Dryomov

fs/dcache: Move the wakeup from __d_lookup_done() to the caller.

2022-07-30T04:36:10+00:00

__d_lookup_done() wakes waiters on dentry->d_wait. On PREEMPT_RT we are not allowed to do that with preemption disabled, since the wakeup acquired wait_queue_head::lock, which is a "sleeping" spinlock on RT. Calling it under dentry->d_lock is not a problem, since that is also a "sleeping" spinlock on the same configs. Unfortunately, two of its callers (__d_add() and __d_move()) are holding more than just ->d_lock and that needs to be dealt with. The key observation is that wakeup can be moved to any point before dropping ->d_lock. As a first step to solve this, move the wake up outside of the hlist_bl_lock() held section. This is safe because: Waiters get inserted into ->d_wait only after they'd taken ->d_lock and observed DCACHE_PAR_LOOKUP in flags. As long as they are woken up (and evicted from the queue) between the moment __d_lookup_done() has removed DCACHE_PAR_LOOKUP and dropping ->d_lock, we are safe, since the waitqueue ->d_wait points to won't get destroyed without having __d_lookup_done(dentry) called (under ->d_lock). ->d_wait is set only by d_alloc_parallel() and only in case when it returns a freshly allocated in-lookup dentry. Whenever that happens, we are guaranteed that __d_lookup_done() will be called for resulting dentry (under ->d_lock) before the wq in question gets destroyed. With two exceptions wq lives in call frame of the caller of d_alloc_parallel() and we have an explicit d_lookup_done() on the resulting in-lookup dentry before we leave that frame. One of those exceptions is nfs_call_unlink(), where wq is embedded into (dynamically allocated) struct nfs_unlinkdata. It is destroyed in nfs_async_unlink_release() after an explicit d_lookup_done() on the dentry wq went into. Remaining exception is d_add_ci(). There wq is what we'd found in ->d_wait of d_add_ci() argument. Callers of d_add_ci() are two instances of ->d_lookup() and they must have been given an in-lookup dentry. Which means that they'd been called by __lookup_slow() or lookup_open(), with wq in the call frame of one of those. Result of d_alloc_parallel() in d_add_ci() is fed to d_splice_alias(), which either returns non-NULL (and d_add_ci() does d_lookup_done()) or feeds dentry to __d_add() that will do __d_lookup_done() under ->d_lock. That concludes the analysis. Let __d_lookup_unhash(): 1) Lock the lookup hash and clear DCACHE_PAR_LOOKUP 2) Unhash the dentry 3) Retrieve and clear dentry::d_wait 4) Unlock the hash and return the retrieved waitqueue head pointer 5) Let the caller handle the wake up. 6) Rename __d_lookup_done() to __d_lookup_unhash_wake() to enforce build failures for OOT code that used __d_lookup_done() and is not aware of the new return value. This does not yet solve the PREEMPT_RT problem completely because preemption is still disabled due to i_dir_seq being held for write. This will be addressed in subsequent steps. An alternative solution would be to switch the waitqueue to a simple waitqueue, but aside of Linus not being a fan of them, moving the wake up closer to the place where dentry::lock is unlocked reduces lock contention time for the woken up waiter. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior Link: https://lkml.kernel.org/r/20220613140712.77932-3-bigeasy@linutronix.de Signed-off-by: Al Viro

fs: move dcache sysctls to its own file

2022-01-22T06:33:36+00:00

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty dishes, this makes it very difficult to maintain. To help with this maintenance let's start by moving sysctls to places where they actually belong. The proc sysctl maintainers do not want to know what sysctl knobs you wish to add for your own piece of code, we just care about the core logic. So move the dcache sysctl clutter out of kernel/sysctl.c. This is a small one-off entry, perhaps later we can simplify this representation, but for now we use the helpers we have. We won't know how we can simplify this further untl we're fully done with the cleanup. [arnd@arndb.de: avoid unused-function warning] Link: https://lkml.kernel.org/r/20211203190123.874239-2-arnd@kernel.org Link: https://lkml.kernel.org/r/20211129205548.605569-4-mcgrof@kernel.org Signed-off-by: Luis Chamberlain Signed-off-by: Arnd Bergmann Cc: Al Viro Cc: Andy Shevchenko Cc: Antti Palosaari Cc: Eric Biederman Cc: Iurii Zaikin Cc: "J. Bruce Fields" Cc: Jeff Layton Cc: Kees Cook Cc: Lukas Middendorf Cc: Stephen Kitt Cc: Xiaoming Ni Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

useful constants: struct qstr for ".."

2021-04-16T02:36:45+00:00

Signed-off-by: Al Viro

constify dentry argument of dentry_path()/dentry_path_raw()

2021-03-21T15:43:58+00:00

Signed-off-by: Al Viro

new helper: d_find_alias_rcu()

2021-01-16T20:12:06+00:00

similar to d_find_alias(inode), except that * the caller must be holding rcu_read_lock() * inode must not be freed until matching rcu_read_unlock() * result is *NOT* pinned and can only be dereferenced until the matching rcu_read_unlock(). Signed-off-by: Al Viro

kernel.h: split out mathematical helpers

2020-12-16T06:46:15+00:00

kernel.h is being used as a dump for all kinds of stuff for a long time. Here is the attempt to start cleaning it up by splitting out mathematical helpers. At the same time convert users in header and lib folder to use new header. Though for time being include new header back to kernel.h to avoid twisted indirected includes for existing users. [sfr@canb.auug.org.au: fix powerpc build] Link: https://lkml.kernel.org/r/20201029150809.13059608@canb.auug.org.au Link: https://lkml.kernel.org/r/20201028173212.41768-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Cc: "Paul E. McKenney" Cc: Trond Myklebust Cc: Jeff Layton Cc: Rasmus Villemoes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fscrypt: rename DCACHE_ENCRYPTED_NAME to DCACHE_NOKEY_NAME

2020-09-24T04:29:49+00:00

Originally we used the term "encrypted name" or "ciphertext name" to mean the encoded filename that is shown when an encrypted directory is listed without its key. But these terms are ambiguous since they also mean the filename stored on-disk. "Encrypted name" is especially ambiguous since it could also be understood to mean "this filename is encrypted on-disk", similar to "encrypted file". So we've started calling these encoded names "no-key names" instead. Therefore, rename DCACHE_ENCRYPTED_NAME to DCACHE_NOKEY_NAME to avoid confusion about what this flag means. Link: https://lore.kernel.org/r/20200924042624.98439-3-ebiggers@kernel.org Signed-off-by: Eric Biggers

vfs: Use sequence counter with associated spinlock

2020-07-29T14:14:27+00:00

A sequence counter write side critical section must be protected by some form of locking to serialize writers. A plain seqcount_t does not contain the information of which lock must be held when entering a write side critical section. Use the new seqcount_spinlock_t data type, which allows to associate a spinlock with the sequence counter. This enables lockdep to verify that the spinlock used for writer serialization is held when the write side critical section is entered. If lockdep is disabled this lock association is compiled out and has neither storage size nor runtime overhead. Signed-off-by: Ahmed S. Darwish Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200720155530.1173732-19-a.darwish@linutronix.de