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path: root/fs/namei.c
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2005-07-12[PATCH] inotifyRobert Love
inotify is intended to correct the deficiencies of dnotify, particularly its inability to scale and its terrible user interface: * dnotify requires the opening of one fd per each directory that you intend to watch. This quickly results in too many open files and pins removable media, preventing unmount. * dnotify is directory-based. You only learn about changes to directories. Sure, a change to a file in a directory affects the directory, but you are then forced to keep a cache of stat structures. * dnotify's interface to user-space is awful. Signals? inotify provides a more usable, simple, powerful solution to file change notification: * inotify's interface is a system call that returns a fd, not SIGIO. You get a single fd, which is select()-able. * inotify has an event that says "the filesystem that the item you were watching is on was unmounted." * inotify can watch directories or files. Inotify is currently used by Beagle (a desktop search infrastructure), Gamin (a FAM replacement), and other projects. See Documentation/filesystems/inotify.txt. Signed-off-by: Robert Love <rml@novell.com> Cc: John McCutchan <ttb@tentacle.dhs.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] namespace: rename _mntput to mntput_no_expireMiklos Szeredi
This patch renames _mntput() to something a little more descriptive: mntput_no_expire(). Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23[PATCH] add some comments to lookup_create()Christoph Hellwig
In a duplicate of lookup_create in the af_unix code Al commented what's going on nicely, so let's bring that over to lookup_create before the copy is going away (I'll send a patch soon) Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (19/19)Al Viro
__do_follow_link() passes potentially worng vfsmount to touch_atime(). It matters only in (currently impossible) case of symlink mounted on something, but it's trivial to fix and that actually makes more sense. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (18/19)Al Viro
Cosmetical cleanups - __follow_mount() calls in __link_path_walk() absorbed into do_lookup(). Obviously equivalent transformation. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (17/19)Al Viro
follow_mount() made void, reordered dput()/mntput() in it. follow_dotdot() switched from struct vfmount ** + struct dentry ** to struct nameidata *; callers updated. Equivalent transformation + fix for too-early-mntput() race. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (16/19)Al Viro
Conditional mntput() moved into __do_follow_link(). There it collapses with unconditional mntget() on the same sucker, closing another too-early-mntput() race. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (15/19)Al Viro
Getting rid of sloppy logics: a) in do_follow_link() we have the wrong vfsmount dropped if our symlink had been mounted on something. Currently it worls only because we never get such situation (modulo filesystem playing dirty tricks on us). And it obfuscates already convoluted logics... b) same goes for open_namei(). c) in __link_path_walk() we have another "it should never happen" sloppiness - out_dput: there does double-free on underlying vfsmount and leaks the covering one if we hit it just after crossing a mountpoint. Again, wrong vfsmount getting dropped. d) another too-early-mntput() race - in do_follow_mount() we need to postpone conditional mntput(path->mnt) until after dput(path->dentry). Again, this one happens only in it-currently-never-happens-unless-some-fs-plays-dirty scenario... Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (14/19)Al Viro
shifted conditional mntput() into do_follow_link() - all callers were doing the same thing. Obviously equivalent transformation. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (13/19)Al Viro
In open_namei() exit_dput: we have mntput() done in the wrong order - if nd->mnt != path.mnt we end up doing mntput(nd->mnt); nd->mnt = path.mnt; dput(nd->dentry); mntput(nd->mnt); which drops nd->dentry too late. Fixed by having path.mnt go first. That allows to switch O_NOFOLLOW under if (__follow_mount(...)) back to exit_dput, while we are at it. Fix for early-mntput() race + equivalent transformation. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (12/19)Al Viro
In open_namei() we take mntput(nd->mnt);nd->mnt=path.mnt; out of the if (__follow_mount(...)), making it conditional on nd->mnt != path.mnt instead. Then we shift the result downstream. Equivalent transformations. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (11/19)Al Viro
shifted conditional mntput() calls in __link_path_walk() downstream. Obviously equivalent transformation. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (10/19)Al Viro
In open_namei(), __follow_down() loop turned into __follow_mount(). Instead of if we are on a mountpoint dentry if O_NOFOLLOW checks fail drop path.dentry drop nd return do equivalent of follow_mount(&path.mnt, &path.dentry) nd->mnt = path.mnt we do if __follow_mount(path) had, indeed, traversed mountpoint /* now both nd->mnt and path.mnt are pinned down */ if O_NOFOLLOW checks fail drop path.dentry drop path.mnt drop nd return mntput(nd->mnt) nd->mnt = path.mnt Now __follow_down() can be folded into follow_down() - no other callers left. We need to reorder dput()/mntput() there - same problem as in follow_mount(). Equivalent transformation + fix for a bug in O_NOFOLLOW handling - we used to get -ELOOP if we had the same fs mounted on /foo and /bar, had something bound on /bar/baz and tried to open /foo/baz with O_NOFOLLOW. And fix of too-early-mntput() race in follow_down() Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (9/19)Al Viro
New helper: __follow_mount(struct path *path). Same as follow_mount(), except that we do *not* do mntput() after the first lookup_mnt(). IOW, original path->mnt stays pinned down. We also take care to do dput() before mntput() in the loop body (follow_mount() also needs that reordering, but that will be done later in the series). The following are equivalent, assuming that path.mnt == x: (1) follow_mount(&path.mnt, &path.dentry) (2) __follow_mount(&path); if (path->mnt != x) mntput(x); (3) if (__follow_mount(&path)) mntput(x); Callers of follow_mount() in __link_path_walk() converted to (2). Equivalent transformation + fix for too-late-mntput() race in __follow_mount() loop. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (8/19)Al Viro
In open_namei() we never use path.mnt or path.dentry after exit: or ok:. Assignment of path.dentry in case of LAST_BIND is dead code and only obfuscates already convoluted function; assignment of path.mnt after __do_follow_link() can be moved down to the place where we set path.dentry. Obviously equivalent transformations, just to clean the air a bit in that region. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (7/19)Al Viro
The first argument of __do_follow_link() switched to struct path * (__do_follow_link(path->dentry, ...) -> __do_follow_link(path, ...)). All callers have the same calls of mntget() right before and dput()/mntput() right after __do_follow_link(); these calls have been moved inside. Obviously equivalent transformations. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (6/19)Al Viro
mntget(path->mnt) in do_follow_link() moved down to right before the __do_follow_link() call and rigth after loop: resp. dput()+mntput() on non-ELOOP branch moved up to right after __do_follow_link() call. resulting loop: mntget(path->mnt); path_release(nd); dput(path->mnt); mntput(path->mnt); replaced with equivalent dput(path->mnt); path_release(nd); Equivalent transformations - the reason why we have that mntget() is that __do_follow_link() can drop a reference to nd->mnt and that's what holds path->mnt. So that call can happen at any point prior to __do_follow_link() touching nd->mnt. The rest is obvious. NOTE: current tree relies on symlinks *never* being mounted on anything. It's not hard to get rid of that assumption (actually, that will come for free later in the series). For now we are just not making the situation worse than it is. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (5/19)Al Viro
fix for too early mntput() in open_namei() - we pin path.mnt down for the duration of __do_follow_link(). Otherwise we could get the fs where our symlink lived unmounted while we were in __do_follow_link(). That would end up with dentry of symlink staying pinned down through the fs shutdown. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (4/19)Al Viro
path.mnt in open_namei() set to mirror nd->mnt. nd->mnt is set in 3 places in that function - path_lookup() in the beginning, __follow_down() loop after do_last: and __do_follow_link() call after do_link:. We set path.mnt to nd->mnt after path_lookup() and __do_follow_link(). In __follow_down() loop we use &path.mnt instead of &nd->mnt and set nd->mnt to path.mnt immediately after that loop. Obviously equivalent transformation. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (3/19)Al Viro
Replaced struct dentry *dentry in namei with struct path path. All uses of dentry replaced with path.dentry there. Obviously equivalent transformation. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixes (2/19)Al Viro
All callers of do_follow_link() do mntget() right before it and dput()+mntput() right after. These calls are moved inside do_follow_link() now. Obviously equivalent transformation. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06[PATCH] namei fixesAl Viro
OK, here comes a patch series that hopefully should close all too-early-mntput() races in fs/namei.c. Entire area is convoluted as hell, so I'm splitting that series into _very_ small chunks. Patches alread in the tree close only (very wide) races in following symlinks (see "busy inodes after umount" thread some time ago). Unfortunately, quite a few narrower races of the same nature were not closed. Hopefully this should take care of all of them. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-19[AF_UNIX]: Use lookup_create().Christoph Hellwig
currently it opencodes it, but that's in the way of chaning the lookup_hash interface. I'd prefer to disallow modular af_unix over exporting lookup_create, but I'll leave that to you. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-05[PATCH] make some things staticAdrian Bunk
This patch makes some needlessly global identifiers static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Arjan van de Ven <arjanv@infradead.org> Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-29namei: add audit_inode to all branches in path_lookupPrasanna Meda
Main change is in path_lookup: added a goto to do audit_inode instead of return statement, when emul_lookup_dentry for root is successful.The existing code does audit_inode only when lookup is done in normal root or cwd. Other changes: Some lookup routines are returning zero on success, and some are returning zero on failure. I documented the related function signatures in this code path, so that one can glance over abstract functions without understanding the entire code. Signed-off-by: Prasanna Meda <pmeda@akamai.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!