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* tidy up namei.c a bitAl Viro2012-07-231-18/+21
| | | | | | locking/unlocking for rcu walk taken to a couple of inline helpers Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* unobfuscate follow_up() a bitAl Viro2012-07-231-1/+1
| | | | | | really convoluted test in there has grown up during struct mount introduction; what it checks is that we'd reached the root of mount tree.
* use __lookup_hash() in kern_path_parent()Al Viro2012-07-221-1/+1
| | | | | | No need to bother with lookup_one_len() here - it's an overkill Signed-off-by Al Viro <viro@zeniv.linux.org.uk>
* VFS: Split inode_permission()David Howells2012-07-141-17/+49
| | | | | | | | | | | | | Split inode_permission() into inode- and superblock-dependent parts. This is aimed at unionmounts where the superblock from the upper layer has to be checked rather than the superblock from the lower layer as the upper layer may be writable, thus allowing an unwritable file from the lower layer to be copied up and modified. Original-author: Valerie Aurora <vaurora@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> (Further development) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* VFS: Comment mount following codeDavid Howells2012-07-141-0/+10
| | | | | | | | | Add comments describing what the directions "up" and "down" mean and ref count handling to the VFS mount following family of functions. Signed-off-by: Valerie Aurora <vaurora@redhat.com> (Original author) Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: add nd_jump_linkChristoph Hellwig2012-07-141-10/+17
| | | | | | | | | | Add a helper that abstracts out the jump to an already parsed struct path from ->follow_link operation from procfs. Not only does this clean up the code by moving the two sides of this game into a single helper, but it also prepares for making struct nameidata private to namei.c Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: move path_put on failure out of ->follow_linkChristoph Hellwig2012-07-141-2/+1
| | | | | | | | | | | | Currently the non-nd_set_link based versions of ->follow_link are expected to do a path_put(&nd->path) on failure. This calling convention is unexpected, undocumented and doesn't match what the nd_set_link-based instances do. Move the path_put out of the only non-nd_set_link based ->follow_link instance into the caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* get rid of kern_path_parent()Al Viro2012-07-141-2/+20
| | | | | | | | | all callers want the same thing, actually - a kinda-sorta analog of kern_path_create(). I.e. they want parent vfsmount/dentry (with ->i_mutex held, to make sure the child dentry is still their child) + the child dentry. Signed-off-by Al Viro <viro@zeniv.linux.org.uk>
* VFS: Fix the banner comment on lookup_open()David Howells2012-07-141-3/+26
| | | | | | | | | | | | Since commit 197e37d9, the banner comment on lookup_open() no longer matches what the function returns. It used to return a struct file pointer or NULL and now it returns an integer and is passed the struct file pointer it is to use amongst its arguments. Update the comment to reflect this. Also add a banner comment to atomic_open(). Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't pass nameidata * to vfs_create()Al Viro2012-07-141-4/+5
| | | | | | all we want is a boolean flag, same as the method gets now Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't pass nameidata to ->create()Al Viro2012-07-141-2/+1
| | | | | | | | boolean "does it have to be exclusive?" flag is passed instead; Local filesystem should just ignore it - the object is guaranteed not to be there yet. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs/namei.c: don't pass nameidata to __lookup_hash() and lookup_real()Al Viro2012-07-141-10/+10
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* stop passing nameidata to ->lookup()Al Viro2012-07-141-1/+1
| | | | | | | | | Just the flags; only NFS cares even about that, but there are legitimate uses for such argument. And getting rid of that completely would require splitting ->lookup() into a couple of methods (at least), so let's leave that alone for now... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs/namei.c: don't pass namedata to lookup_dcache()Al Viro2012-07-141-4/+4
| | | | | | just the flags... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs/namei.c: don't pass nameidata to d_revalidate()Al Viro2012-07-141-6/+6
| | | | | | since the method wrapped by it doesn't need that anymore... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* stop passing nameidata * to ->d_revalidate()Al Viro2012-07-141-1/+1
| | | | | | Just the lookup flags. Die, bastard, die... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs/namei.c: get do_last() and friends return intAl Viro2012-07-141-80/+70
| | | | | | | Same conventions as for ->atomic_open(). Trimmed the forest of labels a bit, while we are at it... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* kill struct opendataAl Viro2012-07-141-23/+25
| | | | | | | | | Just pass struct file *. Methods are happier that way... There's no need to return struct file * from finish_open() now, so let it return int. Next: saner prototypes for parts in namei.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* kill opendata->{mnt,dentry}Al Viro2012-07-141-9/+6
| | | | | | ->filp->f_path is there for purpose... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* make ->atomic_open() return intAl Viro2012-07-141-6/+8
| | | | | | | | | | | | Change of calling conventions: old new NULL 1 file 0 ERR_PTR(-ve) -ve Caller *knows* that struct file *; no need to return it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't modify od->filp at allAl Viro2012-07-141-3/+1
| | | | | | make put_filp() conditional on flag set by finish_open() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ->atomic_open() prototype change - pass int * instead of bool *Al Viro2012-07-141-16/+17
| | | | | | | | | ... and let finish_open() report having opened the file via that sucker. Next step: don't modify od->filp at all. [AV: FILE_CREATE was already used by cifs; Miklos' fix folded] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: move O_DIRECT check to common codeMiklos Szeredi2012-07-141-12/+5
| | | | | | | | Perform open_check_o_direct() in a common place in do_last after opening the file. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): clean up retryMiklos Szeredi2012-07-141-15/+21
| | | | | | | | | Move the lookup retry logic to the bottom of the function to make the normal case simpler to read. Reported-by: David Howells <dhowells@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): clean up boolMiklos Szeredi2012-07-141-14/+14
| | | | | | | | Consistently use bool for boolean values in do_last(). Reported-by: David Howells <dhowells@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): clean up labelsMiklos Szeredi2012-07-141-5/+5
| | | | | | Reported-by: David Howells <dhowells@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): clean up error handlingMiklos Szeredi2012-07-141-15/+8
| | | | | Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: remove open intents from nameidataMiklos Szeredi2012-07-141-50/+45
| | | | | | | | | All users of open intents have been converted to use ->atomic_{open,create}. This patch gets rid of nd->intent.open and related infrastructure. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: add i_op->atomic_open()Miklos Szeredi2012-07-141-2/+201
| | | | | | | | | | | | | | | | | | | | | | | Add a new inode operation which is called on the last component of an open. Using this the filesystem can look up, possibly create and open the file in one atomic operation. If it cannot perform this (e.g. the file type turned out to be wrong) it may signal this by returning NULL instead of an open struct file pointer. i_op->atomic_open() is only called if the last component is negative or needs lookup. Handling cached positive dentries here doesn't add much value: these can be opened using f_op->open(). If the cached file turns out to be invalid, the open can be retried, this time using ->atomic_open() with a fresh dentry. For now leave the old way of using open intents in lookup and revalidate in place. This will be removed once all the users are converted. David Howells noticed that if ->atomic_open() opens the file but does not create it, handle_truncate() will be called on it even if it is not a regular file. Fix this by checking the file type in this case too. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: lookup_open(): expand lookup_hash()Miklos Szeredi2012-07-141-1/+11
| | | | | | | | Copy __lookup_hash() into lookup_open(). The next patch will insert the atomic open call just before the real lookup. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: add lookup_open()Miklos Szeredi2012-07-141-38/+61
| | | | | | | | | | | Split out lookup + maybe create from do_last(). This is the part under i_mutex protection. The function is called lookup_open() and returns a filp even though the open part is not used yet. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): common slow lookupMiklos Szeredi2012-07-141-22/+5
| | | | | | | | | Make the slow lookup part of O_CREAT and non-O_CREAT opens common. This allows atomic_open to be hooked into the slow lookup part. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): separate O_CREAT specific codeMiklos Szeredi2012-07-141-16/+17
| | | | | | | | Check O_CREAT on the slow lookup paths where necessary. This allows the rest to be shared with plain open. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): inline lookup_slow()Miklos Szeredi2012-07-141-2/+15
| | | | | | | Copy lookup_slow() into do_last(). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* namei.c: let follow_link() do put_link() on failureAl Viro2012-07-141-33/+41
| | | | | | | | | | | | | | no need for kludgy "set cookie to ERR_PTR(...) because we failed before we did actual ->follow_link() and want to suppress put_link()", no pointless check in put_link() itself. Callers checked if follow_link() has failed anyway; might as well break out of their loops if that happened, without bothering to call put_link() first. [AV: folded fixes from hch] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: retry last component if opening stale dentryMiklos Szeredi2012-06-011-2/+35
| | | | | | | | | | | | | | | | NFS optimizes away d_revalidates for last component of open. This means that open itself can find the dentry stale. This patch allows the filesystem to return EOPENSTALE and the VFS will retry the lookup on just the last component if possible. If the lookup was done using RCU mode, including the last component, then this is not possible since the parent dentry is lost. In this case fall back to non-RCU lookup. Currently this is not used since NFS will always leave RCU mode. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last() common post lookupMiklos Szeredi2012-06-011-31/+3
| | | | | | | | Now the post lookup code can be shared between O_CREAT and plain opens since they are essentially the same. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): add audit_inode before openMiklos Szeredi2012-06-011-0/+1
| | | | | | | This allows this code to be shared between O_CREAT and plain opens. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): only return EISDIR for O_CREATMiklos Szeredi2012-06-011-1/+1
| | | | | | | This allows this code to be shared between O_CREAT and plain opens. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): check LOOKUP_DIRECTORYMiklos Szeredi2012-06-011-0/+3
| | | | | | | | Check for ENOTDIR before finishing open. This allows this code to be shared between O_CREAT and plain opens. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): make ENOENT exit RCU safeMiklos Szeredi2012-06-011-2/+4
| | | | | | | This will allow this code to be used in RCU mode. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: make follow_link check RCU safeMiklos Szeredi2012-06-011-2/+10
| | | | | | | This will allow this code to be used in RCU mode. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): use inode variableMiklos Szeredi2012-06-011-3/+5
| | | | | | | | Use helper variable instead of path->dentry->d_inode before complete_walk(). This will allow this code to be used in RCU mode. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): inline walk_component()Miklos Szeredi2012-06-011-5/+30
| | | | | | | Copy walk_component() into do_lookup(). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: do_last(): make exit RCU safeMiklos Szeredi2012-06-011-1/+1
| | | | | | | | Allow returning from do_last() with LOOKUP_RCU still set on the "out:" and "exit:" labels. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: split do_lookup()Miklos Szeredi2012-06-011-14/+45
| | | | | | | | | | | | | | Split do_lookup() into two functions: lookup_fast() - does cached lookup without i_mutex lookup_slow() - does lookup with i_mutex Both follow managed dentries. The new functions are needed by atomic_open. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* brlocks/lglocks: API cleanupsAndi Kleen2012-05-291-12/+12
| | | | | | | | | | | | | | | | | | | | | lglocks and brlocks are currently generated with some complicated macros in lglock.h. But there's no reason to not just use common utility functions and put all the data into a common data structure. In preparation, this patch changes the API to look more like normal function calls with pointers, not magic macros. The patch is rather large because I move over all users in one go to keep it bisectable. This impacts the VFS somewhat in terms of lines changed. But no actual behaviour change. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* word-at-a-time: make the interfaces truly genericLinus Torvalds2012-05-261-10/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This changes the interfaces in <asm/word-at-a-time.h> to be a bit more complicated, but a lot more generic. In particular, it allows us to really do the operations efficiently on both little-endian and big-endian machines, pretty much regardless of machine details. For example, if you can rely on a fast population count instruction on your architecture, this will allow you to make your optimized <asm/word-at-a-time.h> file with that. NOTE! The "generic" version in include/asm-generic/word-at-a-time.h is not truly generic, it actually only works on big-endian. Why? Because on little-endian the generic algorithms are wasteful, since you can inevitably do better. The x86 implementation is an example of that. (The only truly non-generic part of the asm-generic implementation is the "find_zero()" function, and you could make a little-endian version of it. And if the Kbuild infrastructure allowed us to pick a particular header file, that would be lovely) The <asm/word-at-a-time.h> functions are as follows: - WORD_AT_A_TIME_CONSTANTS: specific constants that the algorithm uses. - has_zero(): take a word, and determine if it has a zero byte in it. It gets the word, the pointer to the constant pool, and a pointer to an intermediate "data" field it can set. This is the "quick-and-dirty" zero tester: it's what is run inside the hot loops. - "prep_zero_mask()": take the word, the data that has_zero() produced, and the constant pool, and generate an *exact* mask of which byte had the first zero. This is run directly *outside* the loop, and allows the "has_zero()" function to answer the "is there a zero byte" question without necessarily getting exactly *which* byte is the first one to contain a zero. If you do multiple byte lookups concurrently (eg "hash_name()", which looks for both NUL and '/' bytes), after you've done the prep_zero_mask() phase, the result of those can be or'ed together to get the "either or" case. - The result from "prep_zero_mask()" can then be fed into "find_zero()" (to find the byte offset of the first byte that was zero) or into "zero_bytemask()" (to find the bytemask of the bytes preceding the zero byte). The existence of zero_bytemask() is optional, and is not necessary for the normal string routines. But dentry name hashing needs it, so if you enable DENTRY_WORD_AT_A_TIME you need to expose it. This changes the generic strncpy_from_user() function and the dentry hashing functions to use these modified word-at-a-time interfaces. This gets us back to the optimized state of the x86 strncpy that we lost in the previous commit when moving over to the generic version. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparcLinus Torvalds2012-05-241-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull sparc changes from David S. Miller: "This has the generic strncpy_from_user() implementation architectures can now use, which we've been developing on linux-arch over the past few days. For good measure I ran both a 32-bit and a 64-bit glibc testsuite run, and the latter of which pointed out an adjustment I needed to make to sparc's user_addr_max() definition. Linus, you were right, STACK_TOP was not the right thing to use, even on sparc itself :-) From Sam Ravnborg, we have a conversion of sparc32 over to the common alloc_thread_info_node(), since the aspect which originally blocked our doing so (sun4c) has been removed." Fix up trivial arch/sparc/Kconfig and lib/Makefile conflicts. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc: sparc: Fix user_addr_max() definition. lib: Sparc's strncpy_from_user is generic enough, move under lib/ kernel: Move REPEAT_BYTE definition into linux/kernel.h sparc: Increase portability of strncpy_from_user() implementation. sparc: Optimize strncpy_from_user() zero byte search. sparc: Add full proper error handling to strncpy_from_user(). sparc32: use the common implementation of alloc_thread_info_node()
| * kernel: Move REPEAT_BYTE definition into linux/kernel.hDavid S. Miller2012-05-241-0/+1
| | | | | | | | | | | | | | And make sure that everything using it explicitly includes that header file. Signed-off-by: David S. Miller <davem@davemloft.net>