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a8b00268 |
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20-Nov-2023 |
Al Viro <viro@zeniv.linux.org.uk> |
rename(): avoid a deadlock in the case of parents having no common ancestor ... and fix the directory locking documentation and proof of correctness. Holding ->s_vfs_rename_mutex *almost* prevents ->d_parent changes; the case where we really don't want it is splicing the root of disconnected tree to somewhere. In other words, ->s_vfs_rename_mutex is sufficient to stabilize "X is an ancestor of Y" only if X and Y are already in the same tree. Otherwise it can go from false to true, and one can construct a deadlock on that. Make lock_two_directories() report an error in such case and update the callers of lock_rename()/lock_rename_child() to handle such errors. And yes, such conditions are not impossible to create ;-/ Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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22e111ed |
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19-Nov-2023 |
Al Viro <viro@zeniv.linux.org.uk> |
rename(): fix the locking of subdirectories We should never lock two subdirectories without having taken ->s_vfs_rename_mutex; inode pointer order or not, the "order" proposed in 28eceeda130f "fs: Lock moved directories" is not transitive, with the usual consequences. The rationale for locking renamed subdirectory in all cases was the possibility of race between rename modifying .. in a subdirectory to reflect the new parent and another thread modifying the same subdirectory. For a lot of filesystems that's not a problem, but for some it can lead to trouble (e.g. the case when short directory contents is kept in the inode, but creating a file in it might push it across the size limit and copy its contents into separate data block(s)). However, we need that only in case when the parent does change - otherwise ->rename() doesn't need to do anything with .. entry in the first place. Some instances are lazy and do a tautological update anyway, but it's really not hard to avoid. Amended locking rules for rename(): find the parent(s) of source and target if source and target have the same parent lock the common parent else lock ->s_vfs_rename_mutex lock both parents, in ancestor-first order; if neither is an ancestor of another, lock the parent of source first. find the source and target. if source and target have the same parent if operation is an overwriting rename of a subdirectory lock the target subdirectory else if source is a subdirectory lock the source if target is a subdirectory lock the target lock non-directories involved, in inode pointer order if both source and target are such. That way we are guaranteed that parents are locked (for obvious reasons), that any renamed non-directory is locked (nfsd relies upon that), that any victim is locked (emptiness check needs that, among other things) and subdirectory that changes parent is locked (needed to protect the update of .. entries). We are also guaranteed that any operation locking more than one directory either takes ->s_vfs_rename_mutex or locks a parent followed by its child. Cc: stable@vger.kernel.org Fixes: 28eceeda130f "fs: Lock moved directories" Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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1c18edd1 |
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07-Nov-2023 |
Al Viro <viro@zeniv.linux.org.uk> |
__dentry_kill(): new locking scheme Currently we enter __dentry_kill() with parent (along with the victim dentry and victim's inode) held locked. Then we mark dentry refcount as dead call ->d_prune() remove dentry from hash remove it from the parent's list of children unlock the parent, don't need it from that point on detach dentry from inode, unlock dentry and drop the inode (via ->d_iput()) call ->d_release() regain the lock on dentry check if it's on a shrink list (in which case freeing its empty husk has to be left to shrink_dentry_list()) or not (in which case we can free it ourselves). In the former case, mark it as an empty husk, so that shrink_dentry_list() would know it can free the sucker. drop the lock on dentry ... and usually the caller proceeds to drop a reference on the parent, possibly retaking the lock on it. That is painful for a bunch of reasons, starting with the need to take locks out of order, but not limited to that - the parent of positive dentry can change if we drop its ->d_lock, so getting these locks has to be done with care. Moreover, as soon as dentry is out of the parent's list of children, shrink_dcache_for_umount() won't see it anymore, making it appear as if the parent is inexplicably busy. We do work around that by having shrink_dentry_list() decrement the parent's refcount first and put it on shrink list to be evicted once we are done with __dentry_kill() of child, but that may in some cases lead to ->d_iput() on child called after the parent got killed. That doesn't happen in cases where in-tree ->d_iput() instances might want to look at the parent, but that's brittle as hell. Solution: do removal from the parent's list of children in the very end of __dentry_kill(). As the result, the callers do not need to lock the parent and by the time we really need the parent locked, dentry is negative and is guaranteed not to be moved around. It does mean that ->d_prune() will be called with parent not locked. It also means that we might see dentries in process of being torn down while going through the parent's list of children; those dentries will be unhashed, negative and with refcount marked dead. In practice, that's enough for in-tree code that looks through the list of children to do the right thing as-is. Out-of-tree code might need to be adjusted. Calling conventions: __dentry_kill(dentry) is called with dentry->d_lock held, along with ->i_lock of its inode (if any). It either returns the parent (locked, with refcount decremented to 0) or NULL (if there'd been no parent or if refcount decrement for parent hadn't reached 0). lock_for_kill() is adjusted for new requirements - it doesn't touch the parent's ->d_lock at all. Callers adjusted. Note that for dput() we don't need to bother with fast_dput() for the parent - we just need to check retain_dentry() for it, since its ->d_lock is still held since the moment when __dentry_kill() had taken it to remove the victim from the list of children. The kludge with early decrement of parent's refcount in shrink_dentry_list() is no longer needed - shrink_dcache_for_umount() sees the half-killed dentries in the list of children for as long as they are pinning the parent. They are easily recognized and accounted for by select_collect(), so we know we are not done yet. As the result, we always have the expected ordering for ->d_iput()/->d_release() vs. __dentry_kill() of the parent, no exceptions. Moreover, the current rules for shrink lists (one must make sure that shrink_dcache_for_umount() won't happen while any dentries from the superblock in question are on any shrink lists) are gone - shrink_dcache_for_umount() will do the right thing in all cases, taking such dentries out. Their empty husks (memory occupied by struct dentry itself + its external name, if any) will remain on the shrink lists, but they are no obstacles to filesystem shutdown. And such husks will get freed as soon as shrink_dentry_list() of the list they are on gets to them. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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2f42f1eb |
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29-Oct-2023 |
Al Viro <viro@zeniv.linux.org.uk> |
Call retain_dentry() with refcount 0 Instead of bumping it from 0 to 1, calling retain_dentry(), then decrementing it back to 0 (with ->d_lock held all the way through), just leave refcount at 0 through all of that. It will have a visible effect for ->d_delete() - now it can be called with refcount 0 instead of 1 and it can no longer play silly buggers with dropping/regaining ->d_lock. Not that any in-tree instances tried to (it's pretty hard to get right). Any out-of-tree ones will have to adjust (assuming they need any changes). Note that we do not need to extend rcu-critical area here - we have verified that refcount is non-negative after having grabbed ->d_lock, so nobody will be able to free dentry until they get into __dentry_kill(), which won't happen until they manage to grab ->d_lock. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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da549bdd |
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07-Nov-2023 |
Al Viro <viro@zeniv.linux.org.uk> |
dentry: switch the lists of children to hlist Saves a pointer per struct dentry and actually makes the things less clumsy. Cleaned the d_walk() and dcache_readdir() a bit by use of hlist_for_... iterators. A couple of new helpers - d_first_child() and d_next_sibling(), to make the expressions less awful. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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01bc8e9a |
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24-Oct-2023 |
Christian Brauner <brauner@kernel.org> |
porting: document block device freeze and thaw changes Link: https://lore.kernel.org/r/20230927-vfs-super-freeze-v1-7-ecc36d9ab4d9@kernel.org Link: https://lore.kernel.org/r/20231024-vfs-super-freeze-v2-9-599c19f4faac@kernel.org Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
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e21fc203 |
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23-Oct-2023 |
Amir Goldstein <amir73il@gmail.com> |
exportfs: make ->encode_fh() a mandatory method for NFS export Rename the default helper for encoding FILEID_INO32_GEN* file handles to generic_encode_ino32_fh() and convert the filesystems that used the default implementation to use the generic helper explicitly. After this change, exportfs_encode_inode_fh() no longer has a default implementation to encode FILEID_INO32_GEN* file handles. This is a step towards allowing filesystems to encode non-decodeable file handles for fanotify without having to implement any export_operations. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jeff Layton <jlayton@kernel.org> Acked-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20231023180801.2953446-3-amir73il@gmail.com Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
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5aa9130a |
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17-Oct-2023 |
Christian Brauner <brauner@kernel.org> |
porting: update locking requirements Now that s_umount is never taken under open_mutex update the documentation to say so. Link: https://lore.kernel.org/r/20231017184823.1383356-1-hch@lst.de Signed-off-by: Christian Brauner <brauner@kernel.org>
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060e6c7d |
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15-Sep-2023 |
Christian Brauner <brauner@kernel.org> |
porting: document superblock as block device holder We've changed the holder of the block device which has consequences. Document this clearly and in detail so filesystem and vfs developers have a proper digital paper trail. Signed-off-by: Christian Brauner <brauner@kernel.org>
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2ba0dd65 |
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15-Sep-2023 |
Christian Brauner <brauner@kernel.org> |
porting: document new block device opening order We've changed the order of opening block devices and superblock handling. Let's document this so filesystem and vfs developers have a proper digital paper trail. Signed-off-by: Christian Brauner <brauner@kernel.org>
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40d49a3c |
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18-Aug-2023 |
Matthew Wilcox (Oracle) <willy@infradead.org> |
mm: allow ->huge_fault() to be called without the mmap_lock held Remove the checks for the VMA lock being held, allowing the page fault path to call into the filesystem instead of retrying with the mmap_lock held. This will improve scalability for DAX page faults. Also update the documentation to match (and fix some other changes that have happened recently). Link: https://lkml.kernel.org/r/20230818202335.2739663-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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d56b699d |
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14-Aug-2023 |
Bjorn Helgaas <bhelgaas@google.com> |
Documentation: Fix typos Fix typos in Documentation. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20230814212822.193684-4-helgaas@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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3e327154 |
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05-Aug-2023 |
Linus Torvalds <torvalds@linux-foundation.org> |
vfs: get rid of old '->iterate' directory operation All users now just use '->iterate_shared()', which only takes the directory inode lock for reading. Filesystems that never got convered to shared mode now instead use a wrapper that drops the lock, re-takes it in write mode, calls the old function, and then downgrades the lock back to read mode. This way the VFS layer and other callers no longer need to care about filesystems that never got converted to the modern era. The filesystems that use the new wrapper are ceph, coda, exfat, jfs, ntfs, ocfs2, overlayfs, and vboxsf. Honestly, several of them look like they really could just iterate their directories in shared mode and skip the wrapper entirely, but the point of this change is to not change semantics or fix filesystems that haven't been fixed in the last 7+ years, but to finally get rid of the dual iterators. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
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cac2f8b8 |
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22-Sep-2022 |
Christian Brauner <brauner@kernel.org> |
fs: rename current get acl method 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>
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863f144f |
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23-Sep-2022 |
Miklos Szeredi <mszeredi@redhat.com> |
vfs: open inside ->tmpfile() This is in preparation for adding tmpfile support to fuse, which requires that the tmpfile creation and opening are done as a single operation. Replace the 'struct dentry *' argument of i_op->tmpfile with 'struct file *'. Call finish_open_simple() as the last thing in ->tmpfile() instances (may be omitted in the error case). Change d_tmpfile() argument to 'struct file *' as well to make callers more readable. Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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25885a35 |
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16-Aug-2022 |
Al Viro <viro@zeniv.linux.org.uk> |
Change calling conventions for filldir_t filldir_t instances (directory iterators callbacks) used to return 0 for "OK, keep going" or -E... for "stop". Note that it's *NOT* how the error values are reported - the rules for those are callback-dependent and ->iterate{,_shared}() instances only care about zero vs. non-zero (look at emit_dir() and friends). So let's just return bool ("should we keep going?") - it's less confusing that way. The choice between "true means keep going" and "true means stop" is bikesheddable; we have two groups of callbacks - do something for everything in directory, until we run into problem and find an entry in directory and do something to it. The former tended to use 0/-E... conventions - -E<something> on failure. The latter tended to use 0/1, 1 being "stop, we are done". The callers treated anything non-zero as "stop", ignoring which non-zero value did they get. "true means stop" would be more natural for the second group; "true means keep going" - for the first one. I tried both variants and the things like if allocation failed something = -ENOMEM; return true; just looked unnatural and asking for trouble. [folded suggestion from Matthew Wilcox <willy@infradead.org>] Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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868941b1 |
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29-Jun-2022 |
Jason A. Donenfeld <Jason@zx2c4.com> |
fs: remove no_llseek Now that all callers of ->llseek are going through vfs_llseek(), we don't gain anything by keeping no_llseek around. Nothing actually calls it and setting ->llseek to no_lseek is completely equivalent to leaving it NULL. Longer term (== by the end of merge window) we want to remove all such intializations. To simplify the merge window this commit does *not* touch initializers - it only defines no_llseek as NULL (and simplifies the tests on file opening). At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\<no_llseek\>/d' $i done would do it. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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56f5746c |
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22-Feb-2022 |
Matthew Wilcox (Oracle) <willy@infradead.org> |
namei: Merge page_symlink() and __page_symlink() There are no callers of __page_symlink() left, so we can remove that entry point. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org>
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8b9f3ac5 |
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22-Mar-2022 |
Muchun Song <songmuchun@bytedance.com> |
fs: introduce alloc_inode_sb() to allocate filesystems specific inode The allocated inode cache is supposed to be added to its memcg list_lru which should be allocated as well in advance. That can be done by kmem_cache_alloc_lru() which allocates object and list_lru. The file systems is main user of it. So introduce alloc_inode_sb() to allocate file system specific inodes and set up the inode reclaim context properly. The file system is supposed to use alloc_inode_sb() to allocate inodes. In later patches, we will convert all users to the new API. Link: https://lkml.kernel.org/r/20220228122126.37293-4-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Alex Shi <alexs@kernel.org> Cc: Anna Schumaker <Anna.Schumaker@Netapp.com> Cc: Chao Yu <chao@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Fam Zheng <fam.zheng@bytedance.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kari Argillander <kari.argillander@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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f0b65f39 |
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30-Apr-2021 |
Al Viro <viro@zeniv.linux.org.uk> |
iov_iter: replace iov_iter_copy_from_user_atomic() with iterator-advancing variant Replacement is called copy_page_from_iter_atomic(); unlike the old primitive the callers do *not* need to do iov_iter_advance() after it. In case when they end up consuming less than they'd been given they need to do iov_iter_revert() on everything they had not consumed. That, however, needs to be done only on slow paths. All in-tree callers converted. And that kills the last user of iterate_all_kinds() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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ffb37ca3 |
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01-Apr-2021 |
Al Viro <viro@zeniv.linux.org.uk> |
switch file_open_root() to struct path ... and provide file_open_root_mnt(), using the root of given mount. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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14e43bf4 |
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22-Sep-2020 |
Eric Biggers <ebiggers@google.com> |
vfs: don't unnecessarily clone write access for writable fds There's no need for mnt_want_write_file() to increment mnt_writers when the file is already open for writing, provided that mnt_drop_write_file() is changed to conditionally decrement it. We seem to have ended up in the current situation because mnt_want_write_file() used to be paired with mnt_drop_write(), due to mnt_drop_write_file() not having been added yet. So originally mnt_want_write_file() had to always increment mnt_writers. But later mnt_drop_write_file() was added, and all callers of mnt_want_write_file() were paired with it. This makes the compatibility between mnt_want_write_file() and mnt_drop_write() no longer necessary. Therefore, make __mnt_want_write_file() and __mnt_drop_write_file() skip incrementing mnt_writers on files already open for writing. This removes the only caller of mnt_clone_write(), so remove that too. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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e65ce2a5 |
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21-Jan-2021 |
Christian Brauner <christian.brauner@ubuntu.com> |
acl: handle idmapped mounts The posix acl permission checking helpers determine whether a caller is privileged over an inode according to the acls associated with the inode. Add helpers that make it possible to handle acls on idmapped mounts. The vfs and the filesystems targeted by this first iteration make use of posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to translate basic posix access and default permissions such as the ACL_USER and ACL_GROUP type according to the initial user namespace (or the superblock's user namespace) to and from the caller's current user namespace. Adapt these two helpers to handle idmapped mounts whereby we either map from or into the mount's user namespace depending on in which direction we're translating. Similarly, cap_convert_nscap() is used by the vfs to translate user namespace and non-user namespace aware filesystem capabilities from the superblock's user namespace to the caller's user namespace. Enable it to handle idmapped mounts by accounting for the mount's user namespace. In addition the fileystems targeted in the first iteration of this patch series make use of the posix_acl_chmod() and, posix_acl_update_mode() helpers. Both helpers perform permission checks on the target inode. Let them handle idmapped mounts. These two helpers are called when posix acls are set by the respective filesystems to handle this case we extend the ->set() method to take an additional user namespace argument to pass the mount's user namespace down. Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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c42bca92 |
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09-Jan-2021 |
Pavel Begunkov <asml.silence@gmail.com> |
bio: don't copy bvec for direct IO The block layer spends quite a while in blkdev_direct_IO() to copy and initialise bio's bvec. However, if we've already got a bvec in the input iterator it might be reused in some cases, i.e. when new ITER_BVEC_FLAG_FIXED flag is set. Simple tests show considerable performance boost, and it also reduces memory footprint. Suggested-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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9b2e0016 |
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09-Jan-2021 |
Pavel Begunkov <asml.silence@gmail.com> |
bvec/iter: disallow zero-length segment bvecs zero-length bvec segments are allowed in general, but not handled by bio and down the block layer so filtered out. This inconsistency may be confusing and prevent from optimisations. As zero-length segments are useless and places that were generating them are patched, declare them not allowed. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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df820f8d |
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04-Jun-2020 |
Miklos Szeredi <mszeredi@redhat.com> |
ovl: make private mounts longterm Overlayfs is using clone_private_mount() to create internal mounts for underlying layers. These are used for operations requiring a path, such as dentry_open(). Since these private mounts are not in any namespace they are treated as short term, "detached" mounts and mntput() involves taking the global mount_lock, which can result in serious cacheline pingpong. Make these private mounts longterm instead, which trade the penalty on mntput() for a slightly longer shutdown time due to an added RCU grace period when putting these mounts. Introduce a new helper kern_unmount_many() that can take care of multiple longterm mounts with a single RCU grace period. Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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d9a9f484 |
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12-Mar-2020 |
Al Viro <viro@zeniv.linux.org.uk> |
cifs_atomic_open(): fix double-put on late allocation failure several iterations of ->atomic_open() calling conventions ago, we used to need fput() if ->atomic_open() failed at some point after successful finish_open(). Now (since 2016) it's not needed - struct file carries enough state to make fput() work regardless of the point in struct file lifecycle and discarding it on failure exits in open() got unified. Unfortunately, I'd missed the fact that we had an instance of ->atomic_open() (cifs one) that used to need that fput(), as well as the stale comment in finish_open() demanding such late failure handling. Trivially fixed... Fixes: fe9ec8291fca "do_last(): take fput() on error after opening to out:" Cc: stable@kernel.org # v4.7+ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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9195c3e8 |
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31-Jul-2019 |
Mauro Carvalho Chehab <mchehab+samsung@kernel.org> |
docs: fs: porting.rst: fix a broken reference to another doc With all those document shifts, references to documents get broken. Fix one such occurrence at porting.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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25b532ce |
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26-Jul-2019 |
Mauro Carvalho Chehab <mchehab+samsung@kernel.org> |
docs: fs: convert porting to ReST This file has its own proper style, except that, after a while, the coding style gets violated and whitespaces are placed on different ways. As Sphinx and ReST are very sentitive to whitespace differences, I had to opt if each entry after required/mandatory/... fields should start with zero spaces or with a tab. I opted to start them all from the zero position, in order to avoid needing to break lines with more than 80 columns, with would make harder for review. Most of the other changes at porting.rst were made to use an unified notation with works nice as a text file while also produce a good html output after being parsed. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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