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path: root/fs/namespace.c
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* Merge branch 'next' into for-linusJames Morris2010-05-17
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| * security: remove dead hook sb_post_pivotrootEric Paris2010-04-11
| | | | | | | | | | | | | | Unused hook. Remove. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
| * security: remove dead hook sb_post_addmountEric Paris2010-04-11
| | | | | | | | | | | | | | Unused hook. Remove. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
| * security: remove dead hook sb_post_remountEric Paris2010-04-11
| | | | | | | | | | | | | | Unused hook. Remove. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
| * security: remove dead hook sb_umount_busyEric Paris2010-04-11
| | | | | | | | | | | | | | Unused hook. Remove. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
| * security: remove dead hook sb_umount_closeEric Paris2010-04-11
| | | | | | | | | | | | | | Unused hook. Remove. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
| * security: remove sb_check_sb hooksEric Paris2010-04-11
| | | | | | | | | | | | | | Unused hook. Remove it. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* | Fix the regression created by "set S_DEAD on unlink()..." commitAl Viro2010-05-15
|/ | | | | | | | | | | | | | | | | | | | | | | 1) i_flags simply doesn't work for mount/unlink race prevention; we may have many links to file and rm on one of those obviously shouldn't prevent bind on top of another later on. To fix it right way we need to mark _dentry_ as unsuitable for mounting upon; new flag (DCACHE_CANT_MOUNT) is protected by d_flags and i_mutex on the inode in question. Set it (with dont_mount(dentry)) in unlink/rmdir/etc., check (with cant_mount(dentry)) in places in namespace.c that used to check for S_DEAD. Setting S_DEAD is still needed in places where we used to set it (for directories getting killed), since we rely on it for readdir/rmdir race prevention. 2) rename()/mount() protection has another bogosity - we unhash the target before we'd checked that it's not a mountpoint. Fixed. 3) ancient bogosity in pivot_root() - we locked i_mutex on the right directory, but checked S_DEAD on the different (and wrong) one. Noticed and fixed. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: add NOFOLLOW flag to umount(2)Miklos Szeredi2010-03-03
| | | | | | | | | | | | | | Add a new UMOUNT_NOFOLLOW flag to umount(2). This is needed to prevent symlink attacks in unprivileged unmounts (fuse, samba, ncpfs). Additionally, return -EINVAL if an unknown flag is used (and specify an explicitly unused flag: UMOUNT_UNUSED). This makes it possible for the caller to determine if a flag is supported or not. CC: Eugene Teo <eugene@redhat.com> CC: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Mirror MS_KERNMOUNT in ->mnt_flagsAl Viro2010-03-03
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* get rid of useless vfsmount_lock use in put_mnt_ns()Al Viro2010-03-03
| | | | | | | | It hadn't been needed since we'd sanitized the logics in mark_mounts_for_expiry() (which, in turn, used to be a rudiment of bad old times when namespace_sem was per-ns). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* take check for new events in namespace (guts of mounts_poll()) to namespace.cAl Viro2010-03-03
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new helper: iterate_mounts()Al Viro2010-03-03
| | | | | | | apply function to vfsmounts in set returned by collect_mounts(), stop if it returns non-zero. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* VFS: Clean up shared mount flag propagationValerie Aurora2010-03-03
| | | | | | | | | | | | | | | The handling of mount flags in set_mnt_shared() got a little tangled up during previous cleanups, with the following problems: * MNT_PNODE_MASK is defined as a literal constant when it should be a bitwise xor of other MNT_* flags * set_mnt_shared() clears and then sets MNT_SHARED (part of MNT_PNODE_MASK) * MNT_PNODE_MASK could use a comment in mount.h * MNT_PNODE_MASK is a terrible name, change to MNT_SHARED_MASK This patch fixes these problems. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Kill CL_PROPAGATION, sanitize fs/pnode.c:get_source()Al Viro2010-03-03
| | | | | | | | | | | | | | | | First of all, get_source() never results in CL_PROPAGATION alone. We either get CL_MAKE_SHARED (for the continuation of peer group) or CL_SLAVE (slave that is not shared) or both (beginning of peer group among slaves). Massage the code to make that explicit, kill CL_PROPAGATION test in clone_mnt() (nothing sets CL_MAKE_SHARED without CL_PROPAGATION and in clone_mnt() we are checking CL_PROPAGATION after we'd found that there's no CL_SLAVE, so the check for CL_MAKE_SHARED would do just as well). Fix comments, while we are at it... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* do_add_mount() should sanitize mnt_flagsAl Viro2010-01-16
| | | | | | | | MNT_WRITE_HOLD shouldn't leak into new vfsmount and neither should MNT_SHARED (the latter will be set properly, along with the rest of shared-subtree data structures) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mnt_flags fixes in do_remount()Al Viro2010-01-16
| | | | | | | * need vfsmount_lock over modifying it * need to preserve MNT_SHARED/MNT_UNBINDABLE Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* attach_recursive_mnt() needs to hold vfsmount_lock over set_mnt_shared()Al Viro2010-01-16
| | | | | | race in mnt_flags update Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* may_umount() needs namespace_semAl Viro2010-01-16
| | | | | | otherwise it races with clone_mnt() changing mnt_share/mnt_slaves Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Revert "fix mismerge with Trond's stuff (create_mnt_ns() export is gone now)"Linus Torvalds2009-12-17
| | | | | | | | | | | | | | | | | | | | | This reverts commit e9496ff46a20a8592fdc7bdaaf41b45eb808d310. Quoth Al: "it's dependent on a lot of other stuff not currently in mainline and badly broken with current fs/namespace.c. Sorry, badly out-of-order cherry-pick from old queue. PS: there's a large pending series reworking the refcounting and lifetime rules for vfsmounts that will, among other things, allow to rip a subtree away _without_ dissolving connections in it, to be garbage-collected when all active references are gone. It's considerably saner wrt "is the subtree busy" logics, but it's nowhere near being ready for merge at the moment; this changeset is one of the things becoming possible with that sucker, but it certainly shouldn't have been picked during this cycle. My apologies..." Noticed-by: Eric Paris <eparis@redhat.com> Requested-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix mismerge with Trond's stuff (create_mnt_ns() export is gone now)Al Viro2009-12-16
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* LSM: Pass original mount flags to security_sb_mount().Tetsuo Handa2009-10-11
| | | | | | | | | | | | This patch allows LSM modules to determine based on original mount flags passed to mount(). A LSM module can get masked mount flags (if needed) by flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE | MS_NOATIME | MS_NODIRATIME | MS_RELATIME| MS_KERNMOUNT | MS_STRICTATIME); Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
* fs: fix overflow in sys_mount() for in-kernel callsVegard Nossum2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | sys_mount() reads/copies a whole page for its "type" parameter. When do_mount_root() passes a kernel address that points to an object which is smaller than a whole page, copy_mount_options() will happily go past this memory object, possibly dereferencing "wild" pointers that could be in any state (hence the kmemcheck warning, which shows that parts of the next page are not even allocated). (The likelihood of something going wrong here is pretty low -- first of all this only applies to kernel calls to sys_mount(), which are mostly found in the boot code. Secondly, I guess if the page was not mapped, exact_copy_from_user() _would_ in fact handle it correctly because of its access_ok(), etc. checks.) But it is much nicer to avoid the dubious reads altogether, by stopping as soon as we find a NUL byte. Is there a good reason why we can't do something like this, using the already existing strndup_from_user()? [akpm@linux-foundation.org: make copy_mount_string() static] [AV: fix compat mount breakage, which involves undoing akpm's change above] Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: al <al@dizzy.pdmi.ras.ru>
* vfs: mnt_want_write_file(): fix special file handlingOGAWA Hirofumi2009-08-07
| | | | | | | | | | | | | I suspect that mnt_want_write_file() may have wrong assumption. I think mnt_want_write_file() is assuming it increments ->mnt_writers if (file->f_mode & FMODE_WRITE). But, if it's special_file(), it is false? Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Acked-by: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* headers: mnt_namespace.h reduxAlexey Dobriyan2009-07-08
| | | | | | | | | | | | | Fix various silly problems wrt mnt_namespace.h: - exit_mnt_ns() isn't used, remove it - done that, sched.h and nsproxy.h inclusions aren't needed - mount.h inclusion was need for vfsmount_lock, but no longer - remove mnt_namespace.h inclusion from files which don't use anything from mnt_namespace.h Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ... and the same for vfsmount id/mount group idAl Viro2009-06-24
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* VFS: Switch init_mount_tree() to use the new create_mnt_ns() helperTrond Myklebust2009-06-24
| | | | | | | Eliminates some duplicated code... Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* VFS: Add VFS helper functions for setting up private namespacesTrond Myklebust2009-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | The purpose of this patch is to improve the remote mount path lookup support for distributed filesystems such as the NFSv4 client. When given a mount command of the form "mount server:/foo/bar /mnt", the NFSv4 client is required to look up the filehandle for "server:/", and then look up each component of the remote mount path "foo/bar" in order to find the directory that is actually going to be mounted on /mnt. Following that remote mount path may involve following symlinks, crossing server-side mount points and even following referrals to filesystem volumes on other servers. Since the standard VFS path lookup code already supports walking paths that contain all these features (using in-kernel automounts for following referrals) we would like to be able to reuse that rather than duplicate the full path traversal functionality in the NFSv4 client code. This patch therefore defines a VFS helper function create_mnt_ns(), that sets up a temporary filesystem namespace and attaches a root filesystem to it. It exports the create_mnt_ns() and put_mnt_ns() function for use by filesystem modules. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* VFS: Uninline the function put_mnt_ns()Trond Myklebust2009-06-23
| | | | | | | In order to allow modules to use it without having to export vfsmount_lock. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Push BKL down into do_remount_sb()Al Viro2009-06-11
| | | | | | [folded fix from Jiri Slaby] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Push BKL down beyond VFS-only parts of do_mount()Al Viro2009-06-11
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Push BKL into do_mount()Al Viro2009-06-11
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* dcache: extrace and use d_unlinked()Alexey Dobriyan2009-06-11
| | | | | | | | | d_unlinked() will be used in middle-term to ban checkpointing when opened but unlinked file is detected, and in long term, to detect such situation and special case on it. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: introduce mnt_clone_writenpiggin@suse.de2009-06-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch speeds up lmbench lat_mmap test by about another 2% after the first patch. Before: avg = 462.286 std = 5.46106 After: avg = 453.12 std = 9.58257 (50 runs of each, stddev gives a reasonable confidence) It does this by introducing mnt_clone_write, which avoids some heavyweight operations of mnt_want_write if called on a vfsmount which we know already has a write count; and mnt_want_write_file, which can call mnt_clone_write if the file is open for write. After these two patches, mnt_want_write and mnt_drop_write go from 7% on the profile down to 1.3% (including mnt_clone_write). [AV: mnt_want_write_file() should take file alone and derive mnt from it; not only all callers have that form, but that's the only mnt about which we know that it's already held for write if file is opened for write] Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: mnt_want_write speedupnpiggin@suse.de2009-06-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch speeds up lmbench lat_mmap test by about 8%. lat_mmap is set up basically to mmap a 64MB file on tmpfs, fault in its pages, then unmap it. A microbenchmark yes, but it exercises some important paths in the mm. Before: avg = 501.9 std = 14.7773 After: avg = 462.286 std = 5.46106 (50 runs of each, stddev gives a reasonable confidence, but there is quite a bit of variation there still) It does this by removing the complex per-cpu locking and counter-cache and replaces it with a percpu counter in struct vfsmount. This makes the code much simpler, and avoids spinlocks (although the msync is still pretty costly, unfortunately). It results in about 900 bytes smaller code too. It does increase the size of a vfsmount, however. It should also give a speedup on large systems if CPUs are frequently operating on different mounts (because the existing scheme has to operate on an atomic in the struct vfsmount when switching between mounts). But I'm most interested in the single threaded path performance for the moment. [AV: minor cleanup] Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch lookup_mnt()Al Viro2009-06-11
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch follow_down()Al Viro2009-06-11
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Switch collect_mounts() to struct pathAl Viro2009-06-11
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Don't bother with check_mnt() in do_add_mount() on shrinkable onesAl Viro2009-06-11
| | | | | | | | These guys are what we add as submounts; checks for "is that attached in our namespace" are simply irrelevant for those and counterproductive for use of private vfsmount trees a-la what NFS folks want. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Fix races around the access to ->s_optionsAl Viro2009-05-09
| | | | | | | | | Put generic_show_options read access to s_options under rcu_read_lock, split save_mount_options() into "we are setting it the first time" (uses in foo_fill_super()) and "we are relacing and freeing the old one", synchronize_rcu() before kfree() in the latter. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: umount_begin BKL pushdownAlessio Igor Bogani2009-05-09
| | | | | | | Push BKL down into ->umount_begin() Signed-off-by: Alessio Igor Bogani <abogani@texware.it> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Touch all affected namespaces on propagation of mountAl Viro2009-04-20
| | | | | | | We shouldn't just touch the namespace of current process Caught-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Don't set relatime when noatime is specifiedAndi Kleen2009-04-19
| | | | | | | | | | | | | | | | | Since commit 0a1c01c9477602ee8b44548a9405b2c1d587b5a2 ("Make relatime default") when a file system is mounted explicitely with noatime it gets both the MNT_RELATIME and MNT_NOATIME bits set. This shows up like this in /proc/mounts: /dev/xxx /yyy ext3 rw,noatime,relatime,errors=continue,data=writeback 0 0 That looks strange. The VFS uses noatime in this case, but both flags are set. So it's more a cosmetic issue, but still better to fix. Cc: mjg@redhat.com Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Get rid of indirect include of fs_struct.hAl Viro2009-03-31
| | | | | | | | Don't pull it in sched.h; very few files actually need it and those can include directly. sched.h itself only needs forward declaration of struct fs_struct; Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Take fs_struct handling to new file (fs/fs_struct.c)Al Viro2009-03-31
| | | | | | | | | | Pure code move; two new helper functions for nfsd and daemonize (unshare_fs_struct() and daemonize_fs_struct() resp.; for now - the same code as used to be in callers). unshare_fs_struct() exported (for nfsd, as copy_fs_struct()/exit_fs() used to be), copy_fs_struct() and exit_fs() don't need exports anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Get rid of bumping fs_struct refcount in pivot_root(2)Al Viro2009-03-31
| | | | | | | | Not because execve races with _that_ are serious - we really need a situation when final drop of fs_struct refcount is done by something that used to have it as current->fs. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2009-03-27
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (37 commits) fs: avoid I_NEW inodes Merge code for single and multiple-instance mounts Remove get_init_pts_sb() Move common mknod_ptmx() calls into caller Parse mount options just once and copy them to super block Unroll essentials of do_remount_sb() into devpts vfs: simple_set_mnt() should return void fs: move bdev code out of buffer.c constify dentry_operations: rest constify dentry_operations: configfs constify dentry_operations: sysfs constify dentry_operations: JFS constify dentry_operations: OCFS2 constify dentry_operations: GFS2 constify dentry_operations: FAT constify dentry_operations: FUSE constify dentry_operations: procfs constify dentry_operations: ecryptfs constify dentry_operations: CIFS constify dentry_operations: AFS ...
| * vfs: simple_set_mnt() should return voidSukadev Bhattiprolu2009-03-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | simple_set_mnt() is defined as returning 'int' but always returns 0. Callers assume simple_set_mnt() never fails and don't properly cleanup if it were to _ever_ fail. For instance, get_sb_single() and get_sb_nodev() should: up_write(sb->s_unmount); deactivate_super(sb); if simple_set_mnt() fails. Since simple_set_mnt() never fails, would be cleaner if it did not return anything. [akpm@linux-foundation.org: fix build] Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Make relatime defaultMatthew Garrett2009-03-26
| | | | | | | | | | | | | | | | | | Change the default behaviour of the kernel to use relatime for all filesystems. This can be overridden with the "strictatime" mount option. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Add a strictatime mount optionMatthew Garrett2009-03-26
|/ | | | | | | | | Add support for explicitly requesting full atime updates. This makes it possible for kernels to default to relatime but still allow userspace to override it. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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