Print out the name of the file that triggers the cookie loop message to
make it slightly easier to track down the cause.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the directory contents change, then we have to accept that the
file->f_pos value may shrink if we do a 'search-by-cookie'. In that
case, we should turn off the loop detection and let the NFS client
try to recover.
The patch also fixes a second loop detection bug by ensuring
that after turning on the ctx->duped flag, we read at least one new
cookie into ctx->dir_cookie before attempting to match with
ctx->dup_cookie.
Reported-by: Petr Vandrovec <petr@vandrovec.name>
Cc: stable@kernel.org [2.6.39+]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers. Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2. For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
Thanks,
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
a) check the right flags in ->create() (LOOKUP_OPEN, not LOOKUP_CREATE)
b) default (!LOOKUP_OPEN) open_flags is O_CREAT|O_EXCL|FMODE_READ, not 0
c) lookup_instantiate_filp() should be done only with LOOKUP_OPEN;
otherwise we need to issue CLOSE, lest we leak stateid on server.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
its value depends only on inode and does not change; we might as
well store it in ->i_op->check_acl and be done with that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Change each shrinker's API by consolidating the existing parameters into
shrink_control struct. This will simplify any further features added w/o
touching each file of shrinker.
[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: fix warning]
[kosaki.motohiro@jp.fujitsu.com: fix up new shrinker API]
[akpm@linux-foundation.org: fix xfs warning]
[akpm@linux-foundation.org: update gfs2]
Signed-off-by: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A later patch will need to perform a lookup using an
alternate client with a different security flavor.
This patch adds support for doing that on NFS v4.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Some filesystems (such as ext4) can return the same cookie value for
multiple files. If we try to start a readdir with one of these cookies,
the server will return the first file found with a cookie of the same
value. This can cause the client to enter an infinite loop.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
nfs_opendir() created a context that held much more information than we
need for a readdir. This patch introduces a slimmed-down
nfs_open_dir_context that contains only the cookie and the cred used for
RPC operations. The new context will eventually be used to help detect
readdir loops.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we're doing a search by readdir cookie, we need to ensure that the
resulting f_pos is updated. To do so, we need to update the
desc->current_index, in the same way that we do in the search by
file offset case.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
part 2: make sure that disconnected roots have corresponding mnt_devname
values stashed into them.
Have nfs*_get_root() stuff a copy of devname into ->d_fsdata of the
found root, provided that it is disconnected.
Have ->d_release() free it when dentry goes away.
Have the places where NFS uses ->d_fsdata for sillyrename (and that
can *never* happen to a disconnected root - dentry will be attached
to its parent) free old devname copies if they find those.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Make NFS use the new d_automount() dentry operation rather than abusing
follow_link() on directories.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin:
fs: fix do_last error case when need_reval_dot
nfs: add missing rcu-walk check
fs: hlist UP debug fixup
fs: fix dropping of rcu-walk from force_reval_path
fs: force_reval_path drop rcu-walk before d_invalidate
fs: small rcu-walk documentation fixes
Fixed up trivial conflicts in Documentation/filesystems/porting
Commit c0204fd2b8 (NFS: Clean up
nfs4_proc_create()) broke NFSv3 exclusive open by removing the code
that passes the O_EXCL flag down to nfs3_proc_create(). This patch
reverts that offending hunk from the original commit.
Reported-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org [2.6.37]
Tested-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'nfs-for-2.6.38' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (89 commits)
NFS fix the setting of exchange id flag
NFS: Don't use vm_map_ram() in readdir
NFSv4: Ensure continued open and lockowner name uniqueness
NFS: Move cl_delegations to the nfs_server struct
NFS: Introduce nfs_detach_delegations()
NFS: Move cl_state_owners and related fields to the nfs_server struct
NFS: Allow walking nfs_client.cl_superblocks list outside client.c
pnfs: layout roc code
pnfs: update nfs4_callback_recallany to handle layouts
pnfs: add CB_LAYOUTRECALL handling
pnfs: CB_LAYOUTRECALL xdr code
pnfs: change lo refcounting to atomic_t
pnfs: check that partial LAYOUTGET return is ignored
pnfs: add layout to client list before sending rpc
pnfs: serialize LAYOUTGET(openstateid)
pnfs: layoutget rpc code cleanup
pnfs: change how lsegs are removed from layout list
pnfs: change layout state seqlock to a spinlock
pnfs: add prefix to struct pnfs_layout_hdr fields
pnfs: add prefix to struct pnfs_layout_segment fields
...
vm_map_ram() is not available on NOMMU platforms, and causes trouble
on incoherrent architectures such as ARM when we access the page data
through both the direct and the virtual mapping.
The alternative is to use the direct mapping to access page data
for the case when we are not crossing a page boundary, but to copy
the data into a linear scratch buffer when we are accessing data
that spans page boundaries.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: stable@kernel.org [2.6.37]
Require filesystems be aware of .d_revalidate being called in rcu-walk
mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning
-ECHILD from all implementations.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.
Patched with:
git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Change d_delete from a dentry deletion notification to a dentry caching
advise, more like ->drop_inode. Require it to be constant and idempotent,
and not take d_lock. This is how all existing filesystems use the callback
anyway.
This makes fine grained dentry locking of dput and dentry lru scanning
much simpler.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
This patch make nfsv4 use the generic xattr handling code
to get the nfsv4 acl. This will help us to add richacl
support to nfsv4 in later patches
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We want to skip VFS applying mode for NFS. So set MS_POSIXACL always
and selectively use umask. Ideally we would want to use umask only
when we don't have inheritable ACEs set. But NFS currently don't
allow to send umask to the server. So this is best what we can do
and this is consistent with NFSv3
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Use ERR_CAST() intead of wierd-looking cast.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up.
The pointer returned by ->decode_dirent() is no longer used as a
pointer. The only call site (xdr_decode() in fs/nfs/dir.c) simply
extracts the errno value encoded in the pointer. Replace the
returned pointer with a standard integer errno return value.
Also, pass the "server" argument as part of the nfs_entry instead of
as a separate parameter. It's faster to derive "server" in
nfs_readdir_xdr_to_array() since we already have the directory's inode
handy. "server" ought to be invariant for a set of entries in the
same directory, right?
The legacy versions of decode_dirent() don't use "server" anyway, so
it's wasted work for them to derive and pass "server" for each entry.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we're searching for a specific cookie, and it isn't found in the page
cache, we should try an uncached_readdir(). To do so, we return EBADCOOKIE,
but we don't set desc->eof.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We need to ensure that the entries in the nfs_cache_array get cleared
when the page is removed from the page cache. To do so, we use the
freepage address_space operation.
Change nfs_readdir_clear_array to use kmap_atomic(), so that the
function can be safely called from all contexts.
Finally, modify the cache_page_release helper to call
nfs_readdir_clear_array directly, when dealing with an anonymous
page from 'uncached_readdir'.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We need to use the cookie from the previous array entry, not the
actual cookie that we are searching for (except for the case of
uncached_readdir).
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When comparing filehandles in the helper nfs_same_file(), we should not be
using 'strncmp()': filehandles are not null terminated strings.
Instead, we should just use the existing helper nfs_compare_fh().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Store the dirent->d_type in the struct nfs_cache_array_entry so that we
can use it in getdents() calls.
This fixes a regression with the new readdir code.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
It looks as if the array size calculation in MAX_READDIR_ARRAY does not
take the alignment of struct nfs_cache_array_entry into account.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We should ignore the errors from the filldir callback, and just interpret
them as meaning we should exit, however we should definitely pass back
ENOMEM errors.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, uncached_readdir() is broken because if fails to handle
the results from nfs_readdir_xdr_to_array() correctly.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
nfs_do_filldir() must always free desc->page when it is done, otherwise
we end up leaking the page.
Also remove unused variable 'dentry'.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Strings allocated via kmemdup() in nfs_readdir_make_qstr() are
referenced from the nfs_cache_array which is stored in a page cache
page. Kmemleak does not scan such pages and it reports several false
positives. This patch annotates the string->name pointer so that
kmemleak does not consider it a real leak.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix up the issue that array->eof_index needs to be able to be set
even if array->size == 0.
Ensure that we catch all important memory allocation error conditions
and/or kmap() failures.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This reverts commit 80e60639f1.
This change requires further fixes to ensure that the open doesn't
succeed if the lookup later results in a regular file being created.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits)
split invalidate_inodes()
fs: skip I_FREEING inodes in writeback_sb_inodes
fs: fold invalidate_list into invalidate_inodes
fs: do not drop inode_lock in dispose_list
fs: inode split IO and LRU lists
fs: switch bdev inode bdi's correctly
fs: fix buffer invalidation in invalidate_list
fsnotify: use dget_parent
smbfs: use dget_parent
exportfs: use dget_parent
fs: use RCU read side protection in d_validate
fs: clean up dentry lru modification
fs: split __shrink_dcache_sb
fs: improve DCACHE_REFERENCED usage
fs: use percpu counter for nr_dentry and nr_dentry_unused
fs: simplify __d_free
fs: take dcache_lock inside __d_path
fs: do not assign default i_ino in new_inode
fs: introduce a per-cpu last_ino allocator
new helper: ihold()
...
Check if the decoded entry has the eof bit set when returning from xdr_decode
with an error. If it does, we should set the eof bits in the array before
returning. This should keep us from looping when we expect more data but the
server doesn't give us anything new.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Check for all errors, not a specific one.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We can use vmapped pages to read more information from the network at once.
This will reduce the number of calls needed to complete a readdir.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
[trondmy: Added #include for linux/vmalloc.h> in fs/nfs/dir.c]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Convert nfs*xdr.c to use an xdr stream in decode_dirent. This will prevent a
kernel oops that has been occuring when reading a vmapped page.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This patch adds readdir plus support to the cache array.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we're going through the loop in nfs_readdir() more than once, we usually
do not want to restart searching from the beginning of the pages cache.
We only want to do that if the previous search failed...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This patch adds the readdir cache array and functions to retreive the array
stored on a cache page, clear the array by freeing allocated memory, add an
entry to the array, and search the array for a given cookie.
It then modifies readdir to make use of the new cache array.
With the new cache array method, we no longer need some of this code.
Finally, nfs_llseek_dir() will set file->f_pos to a value greater than 0 and
desc->dir_cookie to zero. When we see this, readdir needs to find the file
at position file->f_pos from the start of the directory.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If nfs_intent_set_file() returns an error, we usually want to pass that
back up the stack.
Also ensure that nfs_open_revalidate() returns '1' on success.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
...since that's where most of the sillyrenaming code lives. A comment
block is added to the beginning as well to clarify how sillyrenaming
works. Also, make nfs_async_unlink static as nfs_sillyrename is the only
caller.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Remove all remaining references to the struct nameidata from the low level
NFS layers. Again pass down a partially initialised struct nfs_open_context
when we want to do atomic open+create.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Remove references to 'struct nameidata' from the low-level open_revalidate
code, and replace them with a struct nfs_open_context which will be
correctly initialised upon success.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Start moving the 'struct nameidata' dependent code out of the lower level
NFS code in preparation for the removal of open intents.
Instead of the struct nameidata, we pass down a partially initialised
struct nfs_open_context that will be fully initialised by the atomic open
upon success.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
To obey NFS cache semantics, the client must verify the cached
attributes when a file is opened. In most cases this is done by a call to
d_validate as one of the last steps in path_walk.
However for the root of a filesystem, d_validate is only ever called
on the mounted-on filesystem (except when the path ends '.' or '..').
So NFS has no chance to validate the attributes.
So, in nfs_opendir, we revalidate the attributes if the opened
directory is the mountpoint. This may cause double-validation for "."
and ".." lookups, but that is better than missing regular /path/name
lookups completely.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* 'nfs-for-2.6.36' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (42 commits)
NFS: NFSv4.1 is no longer a "developer only" feature
NFS: NFS_V4 is no longer an EXPERIMENTAL feature
NFS: Fix /proc/mount for legacy binary interface
NFS: Fix the locking in nfs4_callback_getattr
SUNRPC: Defer deleting the security context until gss_do_free_ctx()
SUNRPC: prevent task_cleanup running on freed xprt
SUNRPC: Reduce asynchronous RPC task stack usage
SUNRPC: Move the bound cred to struct rpc_rqst
SUNRPC: Clean up of rpc_bindcred()
SUNRPC: Move remaining RPC client related task initialisation into clnt.c
SUNRPC: Ensure that rpc_exit() always wakes up a sleeping task
SUNRPC: Make the credential cache hashtable size configurable
SUNRPC: Store the hashtable size in struct rpc_cred_cache
NFS: Ensure the AUTH_UNIX credcache is allocated dynamically
NFS: Fix the NFS users of rpc_restart_call()
SUNRPC: The function rpc_restart_call() should return success/failure
NFSv4: Get rid of the bogus RPC_ASSASSINATED(task) checks
NFSv4: Clean up the process of renewing the NFSv4 lease
NFSv4.1: Handle NFS4ERR_DELAY on SEQUENCE correctly
NFS: nfs_rename() should not have to flush out writebacks
...
We don't really support nfs servers that invalidate the file handle after a
rename, so precautions such as flushing out dirty data before renaming the
file are superfluous.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently MAY_ACCESS means that filesystems must check the permissions
right then and not rely on cached results or the results of future
operations on the object. This can be because of a call to sys_access() or
because of a call to chdir() which needs to check search without relying on
any future operations inside that dir. I plan to use MAY_ACCESS for other
purposes in the security system, so I split the MAY_ACCESS and the
MAY_CHDIR cases.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
The current shrinker implementation requires the registered callback
to have global state to work from. This makes it difficult to shrink
caches that are not global (e.g. per-filesystem caches). Pass the shrinker
structure to the callback so that users can embed the shrinker structure
in the context the shrinker needs to operate on and get back to it in the
callback via container_of().
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Commit 9c7e7e2337 (NFS: Don't call iput() in
nfs_access_cache_shrinker) unintentionally removed the spin unlock for the
inode->i_lock.
Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
iput() can potentially attempt to allocate memory, so we should avoid
calling it in a memory shrinker. Instead, rely on the fact that iput() will
call nfs_access_zap_cache().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Both iput() and put_rpccred() might allocate memory under certain
circumstances, so make sure that we don't recurse and deadlock...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
nfs: fix memory leak in nfs_get_sb with CONFIG_NFS_V4
nfs: fix some issues in nfs41_proc_reclaim_complete()
NFS: Ensure that nfs_wb_page() waits for Pg_writeback to clear
NFS: Fix an unstable write data integrity race
nfs: testing for null instead of ERR_PTR()
NFS: rsize and wsize settings ignored on v4 mounts
NFSv4: Don't attempt an atomic open if the file is a mountpoint
SUNRPC: Fix a bug in rpcauth_prune_expired
If dentry found stale happens to be a root of disconnected tree, we
can't d_drop() it; its d_hash is actually part of s_anon and d_drop()
would simply hide it from shrink_dcache_for_umount(), leading to
all sorts of fun, including busy inodes on umount and oopsen after
that.
Bug had been there since at least 2006 (commit c636eb already has it),
so it's definitely -stable fodder.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the NFS_INO_REVAL_FORCED flag is set, that means that we don't yet have
an up to date attribute cache. Even if we hold a delegation, we must
put a GETATTR on the wire.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
Recent change is missing to update "rehash". With that change, it will
become the cause of adding dentry to hash twice.
This explains the reason of Oops (dereference the freed dentry in
__d_lookup()) on my machine.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reported-by: Marvin <marvin24@gmx.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The d_instantiate(new_dentry, NULL) is superfluous, the dentry is
already negative. Rehashing this dummy dentry isn't needed either,
d_move() works fine on an unhashed target.
The re-checking for busy after a failed nfs_sillyrename() is bogus
too: new_dentry->d_count < 2 would be a bug here.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Move unhashing the target to after the check for existence and being a
non-directory.
If renaming a directory then the VFS already unhashes the target if it
is not busy. If it's busy then acquiring more references during the
rename makes no difference.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Comments are wrong or out of date. In particular d_drop() doesn't
free the inode it just unhashes the dentry. And if target is a
directory then it is not checked for being busy.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
VFS already checks if both source and target are directories.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
