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2016-05-09nfs: per-name sillyunlink exclusionAl Viro
use d_alloc_parallel() for sillyunlink/lookup exclusion and explicit rwsem (nfs_rmdir() being a writer and nfs_call_unlink() - a reader) for rmdir/sillyunlink one. That ought to make lookup/readdir/!O_CREAT atomic_open really parallel on NFS. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02nfs: switch to ->iterate_shared()Al Viro
aside of the usual care about seeding dcache from readdir, we need to be careful about the pagecache evictions here. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-07Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 bugfixes from Ted Ts'o: "These changes contains a fix for overlayfs interacting with some (badly behaved) dentry code in various file systems. These have been reviewed by Al and the respective file system mtinainers and are going through the ext4 tree for convenience. This also has a few ext4 encryption bug fixes that were discovered in Android testing (yes, we will need to get these sync'ed up with the fs/crypto code; I'll take care of that). It also has some bug fixes and a change to ignore the legacy quota options to allow for xfstests regression testing of ext4's internal quota feature and to be more consistent with how xfs handles this case" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: ignore quota mount options if the quota feature is enabled ext4 crypto: fix some error handling ext4: avoid calling dquot_get_next_id() if quota is not enabled ext4: retry block allocation for failed DIO and DAX writes ext4: add lockdep annotations for i_data_sem ext4: allow readdir()'s of large empty directories to be interrupted btrfs: fix crash/invalid memory access on fsync when using overlayfs ext4 crypto: use dget_parent() in ext4_d_revalidate() ext4: use file_dentry() ext4: use dget_parent() in ext4_file_open() nfs: use file_dentry() fs: add file_dentry() ext4 crypto: don't let data integrity writebacks fail with ENOMEM ext4: check if in-inode xattr is corrupted in ext4_expand_extra_isize_ea()
2016-04-04mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-26nfs: use file_dentry()Miklos Szeredi
NFS may be used as lower layer of overlayfs and accessing f_path.dentry can lead to a crash. Fix by replacing direct access of file->f_path.dentry with the file_dentry() accessor, which will always return a native object. Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Acked-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: <stable@vger.kernel.org> # v4.2 Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk>
2016-03-14nfs_lookup: don't bother with d_instantiate(dentry, NULL)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22wrappers for ->i_mutex accessAl Viro
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-14Merge tag 'nfs-for-4.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client updates from Trond Myklebust: "Highlights include: Stable fixes: - Fix a regression in the SunRPC socket polling code - Fix the attribute cache revalidation code - Fix race in __update_open_stateid() - Fix an lo->plh_block_lgets imbalance in layoutreturn - Fix an Oopsable typo in ff_mirror_match_fh() Features: - pNFS layout recall performance improvements. - pNFS/flexfiles: Support server-supplied layoutstats sampling period Bugfixes + cleanups: - NFSv4: Don't perform cached access checks before we've OPENed the file - Fix starvation issues with background flushes - Reclaim writes should be flushed as unstable writes if there are already entries in the commit lists - Various bugfixes from Chuck to fix NFS/RDMA send queue ordering problems - Ensure that we propagate fatal layoutget errors back to the application - Fixes for sundry flexfiles layoutstats bugs - Fix files/flexfiles to not cache invalidated layouts in the DS commit buckets" * tag 'nfs-for-4.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (68 commits) NFS: Fix a compile warning about unused variable in nfs_generic_pg_pgios() NFSv4: Fix a compile warning about no prototype for nfs4_ioctl() NFS: Use wait_on_atomic_t() for unlock after readahead SUNRPC: Fixup socket wait for memory NFSv4.1/pNFS: Cleanup constify struct pnfs_layout_range arguments NFSv4.1/pnfs: Cleanup copying of pnfs_layout_range structures NFSv4.1/pNFS: Cleanup pnfs_mark_matching_lsegs_invalid() NFSv4.1/pNFS: Fix a race in initiate_file_draining() NFSv4.1/pNFS: pnfs_error_mark_layout_for_return() must always return layout NFSv4.1/pNFS: pnfs_mark_matching_lsegs_return() should set the iomode NFSv4.1/pNFS: Use nfs4_stateid_copy for copying stateids NFSv4.1/pNFS: Don't pass stateids by value to pnfs_send_layoutreturn() NFS: Relax requirements in nfs_flush_incompatible NFSv4.1/pNFS: Don't queue up a new commit if the layout segment is invalid NFS: Allow multiple commit requests in flight per file NFS/pNFS: Fix up pNFS write reschedule layering violations and bugs SUNRPC: Fix a missing break in rpc_anyaddr() pNFS/flexfiles: Fix an Oopsable typo in ff_mirror_match_fh() NFS: Fix attribute cache revalidation NFS: Ensure we revalidate attributes before using execute_ok() ...
2016-01-14Make sure that highmem pages are not added to symlink page cacheAl Viro
inode_nohighmem() is sufficient to make sure that page_get_link() won't try to allocate a highmem page. Moreover, it is sufficient to make sure that page_symlink/__page_symlink won't do the same thing. However, any filesystem that manually preseeds the symlink's page cache upon symlink(2) needs to make sure that the page it inserts there won't be a highmem one. Fortunately, only nfs and shmem have run afoul of that... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-28NFS: Ensure we revalidate attributes before using execute_ok()Trond Myklebust
Donald Buczek reports that NFS clients can also report incorrect results for access() due to lack of revalidation of attributes before calling execute_ok(). Looking closely, it seems chdir() is afflicted with the same problem. Fix is to ensure we call nfs_revalidate_inode_rcu() or nfs_revalidate_inode() as appropriate before deciding to trust execute_ok(). Reported-by: Donald Buczek <buczek@molgen.mpg.de> Link: http://lkml.kernel.org/r/1451331530-3748-1-git-send-email-buczek@molgen.mpg.de Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28NFSv4: Don't perform cached access checks before we've OPENed the fileTrond Myklebust
Donald Buczek reports that a nfs4 client incorrectly denies execute access based on outdated file mode (missing 'x' bit). After the mode on the server is 'fixed' (chmod +x) further execution attempts continue to fail, because the nfs ACCESS call updates the access parameter but not the mode parameter or the mode in the inode. The root cause is ultimately that the VFS is calling may_open() before the NFS client has a chance to OPEN the file and hence revalidate the access and attribute caches. Al Viro suggests: >>> Make nfs_permission() relax the checks when it sees MAY_OPEN, if you know >>> that things will be caught by server anyway? >> >> That can work as long as we're guaranteed that everything that calls >> inode_permission() with MAY_OPEN on a regular file will also follow up >> with a vfs_open() or dentry_open() on success. Is this always the >> case? > > 1) in do_tmpfile(), followed by do_dentry_open() (not reachable by NFS since > it doesn't have ->tmpfile() instance anyway) > > 2) in atomic_open(), after the call of ->atomic_open() has succeeded. > > 3) in do_last(), followed on success by vfs_open() > > That's all. All calls of inode_permission() that get MAY_OPEN come from > may_open(), and there's no other callers of that puppy. Reported-by: Donald Buczek <buczek@molgen.mpg.de> Link: https://bugzilla.kernel.org/show_bug.cgi?id=109771 Link: http://lkml.kernel.org/r/1451046656-26319-1-git-send-email-buczek@molgen.mpg.de Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-11-03fs/nfs: remove unnecessary new_valid_dev checkYaowei Bai
As new_valid_dev always returns 1, so !new_valid_dev check is not needed, remove it. Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-17NFS: Rename nfs_readdir_free_pagearray() and nfs_readdir_large_page()Anna Schumaker
nfs_readdir_xdr_to_array() uses both a cache array and an array of pages, so I rename these functions to make it clearer how the code works. nfs_readdir_large_page() becomes nfs_readdir_alloc_pages() because this function has absolutely nothing to do with setting up a large page. nfs_readdir_free_pagearray() becomes nfs_readdir_free_pages() to stay consistent with the new alloc_pages() function. Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-17NFS: Remove unused variable "pages_ptr"Anna Schumaker
This variable is initialized to NULL and is never modified before being passed to nfs_readdir_free_large_page(). But that's okay, because nfs_readdir_free_large_page() only seems to exist as a way of calling nfs_readdir_free_pagearray() without this parameter. Let's simplify by removing pages_ptr and nfs_readdir_free_pagearray(). Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-07-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: "Assorted VFS fixes and related cleanups (IMO the most interesting in that part are f_path-related things and Eric's descriptor-related stuff). UFS regression fixes (it got broken last cycle). 9P fixes. fs-cache series, DAX patches, Jan's file_remove_suid() work" [ I'd say this is much more than "fixes and related cleanups". The file_table locking rule change by Eric Dumazet is a rather big and fundamental update even if the patch isn't huge. - Linus ] * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits) 9p: cope with bogus responses from server in p9_client_{read,write} p9_client_write(): avoid double p9_free_req() 9p: forgetting to cancel request on interrupted zero-copy RPC dax: bdev_direct_access() may sleep block: Add support for DAX reads/writes to block devices dax: Use copy_from_iter_nocache dax: Add block size note to documentation fs/file.c: __fget() and dup2() atomicity rules fs/file.c: don't acquire files->file_lock in fd_install() fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation vfs: avoid creation of inode number 0 in get_next_ino namei: make set_root_rcu() return void make simple_positive() public ufs: use dir_pages instead of ufs_dir_pages() pagemap.h: move dir_pages() over there remove the pointless include of lglock.h fs: cleanup slight list_entry abuse xfs: Correctly lock inode when removing suid and file capabilities fs: Call security_ops->inode_killpriv on truncate fs: Provide function telling whether file_remove_privs() will do anything ...
2015-07-01nfs: Don't setting FILE_CREATED flags alwaysKinglong Mee
Commit 5bc2afc2b5 "NFSv4: Honour the 'opened' parameter in the atomic_open() filesystem method" have support the opened arguments now. Also, Commit 03da633aa7 "atomic_open: take care of EEXIST in no-open case with O_CREAT|O_EXCL in fs/namei.c" have change vfs's logical. Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-23make simple_positive() publicAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-26Merge tag 'nfs-for-4.1-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client updates from Trond Myklebust: "Another set of mainly bugfixes and a couple of cleanups. No new functionality in this round. Highlights include: Stable patches: - Fix a regression in /proc/self/mountstats - Fix the pNFS flexfiles O_DIRECT support - Fix high load average due to callback thread sleeping Bugfixes: - Various patches to fix the pNFS layoutcommit support - Do not cache pNFS deviceids unless server notifications are enabled - Fix a SUNRPC transport reconnection regression - make debugfs file creation failure non-fatal in SUNRPC - Another fix for circular directory warnings on NFSv4 "junctioned" mountpoints - Fix locking around NFSv4.2 fallocate() support - Truncating NFSv4 file opens should also sync O_DIRECT writes - Prevent infinite loop in rpcrdma_ep_create() Features: - Various improvements to the RDMA transport code's handling of memory registration - Various code cleanups" * tag 'nfs-for-4.1-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (55 commits) fs/nfs: fix new compiler warning about boolean in switch nfs: Remove unneeded casts in nfs NFS: Don't attempt to decode missing directory entries Revert "nfs: replace nfs_add_stats with nfs_inc_stats when add one" NFS: Rename idmap.c to nfs4idmap.c NFS: Move nfs_idmap.h into fs/nfs/ NFS: Remove CONFIG_NFS_V4 checks from nfs_idmap.h NFS: Add a stub for GETDEVICELIST nfs: remove WARN_ON_ONCE from nfs_direct_good_bytes nfs: fix DIO good bytes calculation nfs: Fetch MOUNTED_ON_FILEID when updating an inode sunrpc: make debugfs file creation failure non-fatal nfs: fix high load average due to callback thread sleeping NFS: Reduce time spent holding the i_mutex during fallocate() NFS: Don't zap caches on fallocate() xprtrdma: Make rpcrdma_{un}map_one() into inline functions xprtrdma: Handle non-SEND completions via a callout xprtrdma: Add "open" memreg op xprtrdma: Add "destroy MRs" memreg op xprtrdma: Add "reset MRs" memreg op ...
2015-04-23NFS: Don't attempt to decode missing directory entriesBenjamin Coddington
If a READDIR reply comes back without any page data, avoid a NULL pointer dereference in xdr_copy_to_scratch(). BUG: unable to handle kernel NULL pointer dereference at 0000000000000001 IP: [<ffffffff813a378d>] memcpy+0xd/0x110 ... Call Trace: ? xdr_inline_decode+0x7a/0xb0 [sunrpc] nfs3_decode_dirent+0x73/0x320 [nfsv3] nfs_readdir_page_filler+0xd5/0x4e0 [nfs] ? nfs3_rpc_wrapper.constprop.9+0x42/0xc0 [nfsv3] nfs_readdir_xdr_to_array+0x1fa/0x330 [nfs] ? mem_cgroup_commit_charge+0xac/0x160 ? nfs_readdir_xdr_to_array+0x330/0x330 [nfs] nfs_readdir_filler+0x22/0x90 [nfs] do_read_cache_page+0x7e/0x1a0 read_cache_page+0x1c/0x20 nfs_readdir+0x18e/0x660 [nfs] ? nfs3_xdr_dec_getattr3res+0x80/0x80 [nfsv3] iterate_dir+0x97/0x130 SyS_getdents+0x94/0x120 ? fillonedir+0xd0/0xd0 system_call_fastpath+0x12/0x17 Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-04-15VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells
that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-03-01NFS: Don't require a filehandle to refresh the inode in nfs_prime_dcache()Trond Myklebust
If the server does not return a valid set of attributes that we can use to either create a file or refresh the inode, then there is no value in calling nfs_prime_dcache(). However if we're just refreshing the inode using the attributes that the server returned, then it shouldn't matter whether or not we have a filehandle, as long as we check the fsid+fileid combination. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-03-01NFS: Don't invalidate a submounted dentry in nfs_prime_dcache()Trond Myklebust
If we're traversing a directory which contains a submounted filesystem, or one that has a referral, the NFS server that is processing the READDIR request will often return information for the underlying (mounted-on) directory. It may, or may not, also return filehandle information. If this happens, and the lookup in nfs_prime_dcache() returns the dentry for the submounted directory, the filehandle comparison will fail, and we call d_invalidate(). Post-commit 8ed936b5671bf ("vfs: Lazily remove mounts on unlinked files and directories."), this means the entire subtree is unmounted. The following minimal patch addresses this problem by punting on the invalidation if there is a submount. Kudos to Neil Brown <neilb@suse.de> for having tracked down this issue (see link). Reported-by: Nix <nix@esperi.org.uk> Link: http://lkml.kernel.org/r/87iofju9ht.fsf@spindle.srvr.nix Cc: stable@vger.kernel.org # 3.18+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-12-08Merge branch 'iov_iter' into for-nextAl Viro
2014-11-19assorted conversions to %p[dD]Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-19switch d_materialise_unique() users to d_splice_alias()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-04NFSv4: Ensure nfs_atomic_open set the dentry verifier on ENOENTTrond Myklebust
If the OPEN rpc call to the server fails with an ENOENT call, nfs_atomic_open will create a negative dentry for that file, however it currently fails to call nfs_set_verifier(), thus causing the dentry to be immediately revalidated on the next call to nfs_lookup_revalidate() instead of following the usual lookup caching rules. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-10-09vfs: Make d_invalidate return voidEric W. Biederman
Now that d_invalidate can no longer fail, stop returning a useless return code. For the few callers that checked the return code update remove the handling of d_invalidate failure. Reviewed-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09vfs: Remove unnecessary calls of check_submounts_and_dropEric W. Biederman
Now that check_submounts_and_drop can not fail and is called from d_invalidate there is no longer a need to call check_submounts_and_drom from filesystem d_revalidate methods so remove it. Reviewed-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-04NFS: fix two problems in lookup_revalidate in RCU-walkNeilBrown
1/ rcu_dereference isn't correct: that field isn't RCU protected. It could potentially change at any time so ACCESS_ONCE might be justified. changes to ->d_parent are protected by ->d_seq. However that isn't always checked after ->d_revalidate is called, so it is safest to keep the double-check that ->d_parent hasn't changed at the end of these functions. 2/ in nfs4_lookup_revalidate, "->d_parent" was forgotten. So 'parent' was not the parent of 'dentry'. This fails safe is the context is that dentry->d_inode is NULL, and the result of parent->d_inode being NULL is that ECHILD is returned, which is always safe. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-08-03NFS: allow lockless access to access_cacheNeilBrown
The access cache is used during RCU-walk path lookups, so it is best to avoid locking if possible as taking a lock kills concurrency. The rbtree is not rcu-safe and cannot easily be made so. Instead we simply check the last (i.e. most recent) entry on the LRU list. If this doesn't match, then we return -ECHILD and retry in lock/refcount mode. This requires freeing the nfs_access_entry struct with rcu, and requires using rcu access primatives when adding entries to the lru, and when examining the last entry. Calling put_rpccred before kfree_rcu looks a bit odd, but as put_rpccred already provides rcu protection, we know that the cred will not actually be freed until the next grace period, so any concurrent access will be safe. This patch provides about 5% performance improvement on a stat-heavy synthetic work load with 4 threads on a 2-core CPU. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-08-03NFS: teach nfs_lookup_verify_inode to handle LOOKUP_RCUNeilBrown
It fails with -ECHILD rather than make an RPC call. This allows nfs_lookup_revalidate to call it in RCU-walk mode. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-08-03NFS: teach nfs_neg_need_reval to understand LOOKUP_RCUNeilBrown
This requires nfs_check_verifier to take an rcu_walk flag, and requires an rcu version of nfs_revalidate_inode which returns -ECHILD rather than making an RPC call. With this, nfs_lookup_revalidate can call nfs_neg_need_reval in RCU-walk mode. We can also move the LOOKUP_RCU check past the nfs_check_verifier() call in nfs_lookup_revalidate. If RCU_WALK prevents nfs_check_verifier or nfs_neg_need_reval from doing a full check, they return a status indicating that a revalidation is required. As this revalidation will not be possible in RCU_WALK mode, -ECHILD will ultimately be returned, which is the desired result. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-08-03NFS: support RCU_WALK in nfs_permission()NeilBrown
nfs_permission makes two calls which are not always safe in RCU_WALK, rpc_lookup_cred and nfs_do_access. The second can easily be made rcu-safe by aborting with -ECHILD before making the RPC call. The former can be made rcu-safe by calling rpc_lookup_cred_nonblock() instead. As this will almost always succeed, we use it even when RCU_WALK isn't being used as it still saves some spinlocks in a common case. We only fall back to rpc_lookup_cred() if rpc_lookup_cred_nonblock() fails and MAY_NOT_BLOCK isn't set. This optimisation (always trying rpc_lookup_cred_nonblock()) is particularly important when a security module is active. In that case inode_permission() may return -ECHILD from security_inode_permission() even though ->permission() succeeded in RCU_WALK mode. This leads to may_lookup() retrying inode_permission after performing unlazy_walk(). The spinlock that rpc_lookup_cred() takes is often more expensive than anything security_inode_permission() does, so that spinlock becomes the main bottleneck. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-08-03NFS: prepare for RCU-walk support but pushing tests later in code.NeilBrown
nfs_lookup_revalidate, nfs4_lookup_revalidate, and nfs_permission all need to understand and handle RCU-walk for NFS to gain the benefits of RCU-walk for cached information. Currently these functions all immediately return -ECHILD if the relevant flag (LOOKUP_RCU or MAY_NOT_BLOCK) is set. This patch pushes those tests later in the code so that we only abort immediately before we enter rcu-unsafe code. As subsequent patches make that rcu-unsafe code rcu-safe, several of these new tests will disappear. With this patch there are several paths through the code which will no longer return -ECHILD during an RCU-walk. However these are mostly error paths or other uninteresting cases. A noteworthy change in nfs_lookup_revalidate is that we don't take (or put) the reference to ->d_parent when LOOKUP_RCU is set. Rather we rcu_dereference ->d_parent, and check that ->d_inode is not NULL. We also check that ->d_parent hasn't changed after all the tests. In nfs4_lookup_revalidate we simply avoid testing LOOKUP_RCU on the path that only calls nfs_lookup_revalidate() as that function already performs the required test. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-08-03NFS: nfs4_lookup_revalidate: only evaluate parent if it will be used.NeilBrown
nfs4_lookup_revalidate only uses 'parent' to get 'dir', and only uses 'dir' if 'inode == NULL'. So we don't need to find out what 'parent' or 'dir' is until we know that 'inode' is NULL. By moving 'dget_parent' inside the 'if', we can reduce the number of call sites for 'dput(parent)'. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-08-03NFS: Enforce an upper limit on the number of cached access callTrond Myklebust
This may be used to limit the number of cached credentials building up inside the access cache. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-04-18arch: Mass conversion of smp_mb__*()Peter Zijlstra
Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-06Merge tag 'nfs-for-3.15-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client updates from Trond Myklebust: "Highlights include: - Stable fix for a use after free issue in the NFSv4.1 open code - Fix the SUNRPC bi-directional RPC code to account for TCP segmentation - Optimise usage of readdirplus when confronted with 'ls -l' situations - Soft mount bugfixes - NFS over RDMA bugfixes - NFSv4 close locking fixes - Various NFSv4.x client state management optimisations - Rename/unlink code cleanups" * tag 'nfs-for-3.15-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (28 commits) nfs: pass string length to pr_notice message about readdir loops NFSv4: Fix a use-after-free problem in open() SUNRPC: rpc_restart_call/rpc_restart_call_prepare should clear task->tk_status SUNRPC: Don't let rpc_delay() clobber non-timeout errors SUNRPC: Ensure call_connect_status() deals correctly with SOFTCONN tasks SUNRPC: Ensure call_status() deals correctly with SOFTCONN tasks NFSv4: Ensure we respect soft mount timeouts during trunking discovery NFSv4: Schedule recovery if nfs40_walk_client_list() is interrupted NFS: advertise only supported callback netids SUNRPC: remove KERN_INFO from dprintk() call sites SUNRPC: Fix large reads on NFS/RDMA NFS: Clean up: revert increase in READDIR RPC buffer max size SUNRPC: Ensure that call_bind times out correctly SUNRPC: Ensure that call_connect times out correctly nfs: emit a fsnotify_nameremove call in sillyrename codepath nfs: remove synchronous rename code nfs: convert nfs_rename to use async_rename infrastructure nfs: make nfs_async_rename non-static nfs: abstract out code needed to complete a sillyrename NFSv4: Clear the open state flags if the new stateid does not match ...
2014-04-05nfs: pass string length to pr_notice message about readdir loopsJeff Layton
There is no guarantee that the strings in the nfs_cache_array will be NULL-terminated. In the event that we end up hitting a readdir loop, we need to ensure that we pass the warning message the length of the string. Reported-by: Lachlan McIlroy <lmcilroy@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-03-17nfs: convert nfs_rename to use async_rename infrastructureJeff Layton
There isn't much sense in maintaining two separate versions of rename code. Convert nfs_rename to use the asynchronous rename infrastructure that nfs_sillyrename uses, and emulate synchronous behavior by having the task just wait on the reply. Signed-off-by: Jeff Layton <jlayton@redhat.com> Tested-by: Anna Schumaker <Anna.Schumaker@netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-02-11NFS: Be more aggressive in using readdirplus for 'ls -l' situationsTrond Myklebust
Try to detect 'ls -l' by having nfs_getattr() look at whether or not there is an opendir() file descriptor for the parent directory. If so, then assume that we want to force use of readdirplus in order to avoid the multiple GETATTR calls over the wire. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-02-10mm: fix page leak at nfs_symlink()Rafael Aquini
Changes in commit a0b8cab3b9b2 ("mm: remove lru parameter from __pagevec_lru_add and remove parts of pagevec API") have introduced a call to add_to_page_cache_lru() which causes a leak in nfs_symlink() as now the page gets an extra refcount that is not dropped. Jan Stancek observed and reported the leak effect while running test8 from Connectathon Testsuite. After several iterations over the test case, which creates several symlinks on a NFS mountpoint, the test system was quickly getting into an out-of-memory scenario. This patch fixes the page leak by dropping that extra refcount add_to_page_cache_lru() is grabbing. Signed-off-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Rafael Aquini <aquini@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Jeff Layton <jlayton@redhat.com> Cc: Trond Myklebust <trond.myklebust@primarydata.com> Cc: <stable@vger.kernel.org> [3.11.x+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-28nfs: add memory barriers around NFS_INO_INVALID_DATA and NFS_INO_INVALIDATINGJeff Layton
If the setting of NFS_INO_INVALIDATING gets reordered to before the clearing of NFS_INO_INVALID_DATA, then another task may hit a race window where both appear to be clear, even though the inode's pages are still in need of invalidation. Fix this by adding the appropriate memory barriers. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-01-27NFS: fix the handling of NFS_INO_INVALID_DATA flag in nfs_revalidate_mappingJeff Layton
There is a possible race in how the nfs_invalidate_mapping function is handled. Currently, we go and invalidate the pages in the file and then clear NFS_INO_INVALID_DATA. The problem is that it's possible for a stale page to creep into the mapping after the page was invalidated (i.e., via readahead). If another writer comes along and sets the flag after that happens but before invalidate_inode_pages2 returns then we could clear the flag without the cache having been properly invalidated. So, we must clear the flag first and then invalidate the pages. Doing this however, opens another race: It's possible to have two concurrent read() calls that end up in nfs_revalidate_mapping at the same time. The first one clears the NFS_INO_INVALID_DATA flag and then goes to call nfs_invalidate_mapping. Just before calling that though, the other task races in, checks the flag and finds it cleared. At that point, it trusts that the mapping is good and gets the lock on the page, allowing the read() to be satisfied from the cache even though the data is no longer valid. These effects are easily manifested by running diotest3 from the LTP test suite on NFS. That program does a series of DIO writes and buffered reads. The operations are serialized and page-aligned but the existing code fails the test since it occasionally allows a read to come out of the cache incorrectly. While mixing direct and buffered I/O isn't recommended, I believe it's possible to hit this in other ways that just use buffered I/O, though that situation is much harder to reproduce. The problem is that the checking/clearing of that flag and the invalidation of the mapping really need to be atomic. Fix this by serializing concurrent invalidations with a bitlock. At the same time, we also need to allow other places that check NFS_INO_INVALID_DATA to check whether we might be in the middle of invalidating the file, so fix up a couple of places that do that to look for the new NFS_INO_INVALIDATING flag. Doing this requires us to be careful not to set the bitlock unnecessarily, so this code only does that if it believes it will be doing an invalidation. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-01-05NFS: dprintk() should not print negative fileids and inode numbersNiels de Vos
A fileid in NFS is a uint64. There are some occurrences where dprintk() outputs a signed fileid. This leads to confusion and more difficult to read debugging (negative fileids matching positive inode numbers). Signed-off-by: Niels de Vos <ndevos@redhat.com> CC: Santosh Pradhan <spradhan@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2013-11-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "All kinds of stuff this time around; some more notable parts: - RCU'd vfsmounts handling - new primitives for coredump handling - files_lock is gone - Bruce's delegations handling series - exportfs fixes plus misc stuff all over the place" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (101 commits) ecryptfs: ->f_op is never NULL locks: break delegations on any attribute modification locks: break delegations on link locks: break delegations on rename locks: helper functions for delegation breaking locks: break delegations on unlink namei: minor vfs_unlink cleanup locks: implement delegations locks: introduce new FL_DELEG lock flag vfs: take i_mutex on renamed file vfs: rename I_MUTEX_QUOTA now that it's not used for quotas vfs: don't use PARENT/CHILD lock classes for non-directories vfs: pull ext4's double-i_mutex-locking into common code exportfs: fix quadratic behavior in filehandle lookup exportfs: better variable name exportfs: move most of reconnect_path to helper function exportfs: eliminate unused "noprogress" counter exportfs: stop retrying once we race with rename/remove exportfs: clear DISCONNECTED on all parents sooner exportfs: more detailed comment for path_reconnect ...
2013-10-28Merge branch 'fscache' of ↵Trond Myklebust
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into linux-next Pull fs-cache fixes from David Howells: Can you pull these commits to fix an issue with NFS whereby caching can be enabled on a file that is open for writing by subsequently opening it for reading. This can be made to crash by opening it for writing again if you're quick enough. The gist of the patchset is that the cookie should be acquired at inode creation only and subsequently enabled and disabled as appropriate (which dispenses with the backing objects when they're not needed). The extra synchronisation that NFS does can then be dispensed with as it is thenceforth managed by FS-Cache. Could you send these on to Linus? This likely will need fixing also in CIFS and 9P also once the FS-Cache changes are upstream. AFS and Ceph are probably safe. * 'fscache' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open() FS-Cache: Provide the ability to enable/disable cookies FS-Cache: Add use/unuse/wake cookie wrappers
2013-10-28nfs: use IS_ROOT not DCACHE_DISCONNECTEDJ. Bruce Fields
This check was added by Al Viro with d9e80b7de91db05c1c4d2e5ebbfd70b3b3ba0e0f "nfs d_revalidate() is too trigger-happy with d_drop()", with the explanation that we don't want to remove the root of a disconnected tree, which will still be included on the s_anon list. But DCACHE_DISCONNECTED does *not* actually identify dentries that are disconnected from the dentry tree or hashed on s_anon. IS_ROOT() is the way to do that. Also add a comment from Al's commit to remind us why this check is there. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-10-24nfs: use %p[dD] instead of open-coded (and often racy) equivalentsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-27NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open()David Howells
Use i_writecount to control whether to get an fscache cookie in nfs_open() as NFS does not do write caching yet. I *think* this is the cause of a problem encountered by Mark Moseley whereby __fscache_uncache_page() gets a NULL pointer dereference because cookie->def is NULL: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 IP: [<ffffffff812a1903>] __fscache_uncache_page+0x23/0x160 PGD 0 Thread overran stack, or stack corrupted Oops: 0000 [#1] SMP Modules linked in: ... CPU: 7 PID: 18993 Comm: php Not tainted 3.11.1 #1 Hardware name: Dell Inc. PowerEdge R420/072XWF, BIOS 1.3.5 08/21/2012 task: ffff8804203460c0 ti: ffff880420346640 RIP: 0010:[<ffffffff812a1903>] __fscache_uncache_page+0x23/0x160 RSP: 0018:ffff8801053af878 EFLAGS: 00210286 RAX: 0000000000000000 RBX: ffff8800be2f8780 RCX: ffff88022ffae5e8 RDX: 0000000000004c66 RSI: ffffea00055ff440 RDI: ffff8800be2f8780 RBP: ffff8801053af898 R08: 0000000000000001 R09: 0000000000000003 R10: 0000000000000000 R11: 0000000000000000 R12: ffffea00055ff440 R13: 0000000000001000 R14: ffff8800c50be538 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88042fc60000(0063) knlGS:00000000e439c700 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000001d8f000 CR4: 00000000000607f0 Stack: ... Call Trace: [<ffffffff81365a72>] __nfs_fscache_invalidate_page+0x42/0x70 [<ffffffff813553d5>] nfs_invalidate_page+0x75/0x90 [<ffffffff811b8f5e>] truncate_inode_page+0x8e/0x90 [<ffffffff811b90ad>] truncate_inode_pages_range.part.12+0x14d/0x620 [<ffffffff81d6387d>] ? __mutex_lock_slowpath+0x1fd/0x2e0 [<ffffffff811b95d3>] truncate_inode_pages_range+0x53/0x70 [<ffffffff811b969d>] truncate_inode_pages+0x2d/0x40 [<ffffffff811b96ff>] truncate_pagecache+0x4f/0x70 [<ffffffff81356840>] nfs_setattr_update_inode+0xa0/0x120 [<ffffffff81368de4>] nfs3_proc_setattr+0xc4/0xe0 [<ffffffff81357f78>] nfs_setattr+0xc8/0x150 [<ffffffff8122d95b>] notify_change+0x1cb/0x390 [<ffffffff8120a55b>] do_truncate+0x7b/0xc0 [<ffffffff8121f96c>] do_last+0xa4c/0xfd0 [<ffffffff8121ffbc>] path_openat+0xcc/0x670 [<ffffffff81220a0e>] do_filp_open+0x4e/0xb0 [<ffffffff8120ba1f>] do_sys_open+0x13f/0x2b0 [<ffffffff8126aaf6>] compat_SyS_open+0x36/0x50 [<ffffffff81d7204c>] sysenter_dispatch+0x7/0x24 The code at the instruction pointer was disassembled: > (gdb) disas __fscache_uncache_page > Dump of assembler code for function __fscache_uncache_page: > ... > 0xffffffff812a18ff <+31>: mov 0x48(%rbx),%rax > 0xffffffff812a1903 <+35>: cmpb $0x0,0x10(%rax) > 0xffffffff812a1907 <+39>: je 0xffffffff812a19cd <__fscache_uncache_page+237> These instructions make up: ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); That cmpb is the faulting instruction (%rax is 0). So cookie->def is NULL - which presumably means that the cookie has already been at least partway through __fscache_relinquish_cookie(). What I think may be happening is something like a three-way race on the same file: PROCESS 1 PROCESS 2 PROCESS 3 =============== =============== =============== open(O_TRUNC|O_WRONLY) open(O_RDONLY) open(O_WRONLY) -->nfs_open() -->nfs_fscache_set_inode_cookie() nfs_fscache_inode_lock() nfs_fscache_disable_inode_cookie() __fscache_relinquish_cookie() nfs_inode->fscache = NULL <--nfs_fscache_set_inode_cookie() -->nfs_open() -->nfs_fscache_set_inode_cookie() nfs_fscache_inode_lock() nfs_fscache_enable_inode_cookie() __fscache_acquire_cookie() nfs_inode->fscache = cookie <--nfs_fscache_set_inode_cookie() <--nfs_open() -->nfs_setattr() ... ... -->nfs_invalidate_page() -->__nfs_fscache_invalidate_page() cookie = nfsi->fscache -->nfs_open() -->nfs_fscache_set_inode_cookie() nfs_fscache_inode_lock() nfs_fscache_disable_inode_cookie() -->__fscache_relinquish_cookie() -->__fscache_uncache_page(cookie) <crash> <--__fscache_relinquish_cookie() nfs_inode->fscache = NULL <--nfs_fscache_set_inode_cookie() What is needed is something to prevent process #2 from reacquiring the cookie - and I think checking i_writecount should do the trick. It's also possible to have a two-way race on this if the file is opened O_TRUNC|O_RDONLY instead. Reported-by: Mark Moseley <moseleymark@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
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