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linux/fs/mount.h

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vfs: new internal helper: mnt_has_parent(mnt) vfsmounts have ->mnt_parent pointing either to a different vfsmount or to itself; it's never NULL and termination condition in loops traversing the tree towards root is mnt == mnt->mnt_parent. At least one place (see the next patch) is confused about what's going on; let's add an explicit helper checking it right way and use it in all places where we need it. Not that there had been too many, but... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-23 19:26:23 -05:00
vfs: take /proc/*/mounts and friends to fs/proc_namespace.c rationale: that stuff is far tighter bound to fs/namespace.c than to the guts of procfs proper. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-06 12:21:54 -05:00
proc: Usable inode numbers for the namespace file descriptors. Assign a unique proc inode to each namespace, and use that inode number to ensure we only allocate at most one proc inode for every namespace in proc. A single proc inode per namespace allows userspace to test to see if two processes are in the same namespace. This has been a long requested feature and only blocked because a naive implementation would put the id in a global space and would ultimately require having a namespace for the names of namespaces, making migration and certain virtualization tricks impossible. We still don't have per superblock inode numbers for proc, which appears necessary for application unaware checkpoint/restart and migrations (if the application is using namespace file descriptors) but that is now allowd by the design if it becomes important. I have preallocated the ipc and uts initial proc inode numbers so their structures can be statically initialized. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-06-15 10:21:48 -07:00
switch mnt_namespace ->root to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-06 13:32:36 -05:00
vfs: take /proc/*/mounts and friends to fs/proc_namespace.c rationale: that stuff is far tighter bound to fs/namespace.c than to the guts of procfs proper. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-06 12:21:54 -05:00
vfs: Add a user namespace reference from struct mnt_namespace This will allow for support for unprivileged mounts in a new user namespace. Acked-by: "Serge E. Hallyn" <serge@hallyn.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-07-26 21:08:32 -07:00
vfs: Add setns support for the mount namespace setns support for the mount namespace is a little tricky as an arbitrary decision must be made about what to set fs->root and fs->pwd to, as there is no expectation of a relationship between the two mount namespaces. Therefore I arbitrarily find the root mount point, and follow every mount on top of it to find the top of the mount stack. Then I set fs->root and fs->pwd to that location. The topmost root of the mount stack seems like a reasonable place to be. Bind mount support for the mount namespace inodes has the possibility of creating circular dependencies between mount namespaces. Circular dependencies can result in loops that prevent mount namespaces from every being freed. I avoid creating those circular dependencies by adding a sequence number to the mount namespace and require all bind mounts be of a younger mount namespace into an older mount namespace. Add a helper function proc_ns_inode so it is possible to detect when we are attempting to bind mound a namespace inode. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2010-03-07 18:49:36 -08:00
vfs: take /proc/*/mounts and friends to fs/proc_namespace.c rationale: that stuff is far tighter bound to fs/namespace.c than to the guts of procfs proper. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-06 12:21:54 -05:00
vfs: new internal helper: mnt_has_parent(mnt) vfsmounts have ->mnt_parent pointing either to a different vfsmount or to itself; it's never NULL and termination condition in loops traversing the tree towards root is mnt == mnt->mnt_parent. At least one place (see the next patch) is confused about what's going on; let's add an explicit helper checking it right way and use it in all places where we need it. Not that there had been too many, but... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-23 19:26:23 -05:00
vfs: all counters taken to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-24 22:53:09 -05:00
vfs: start hiding vfsmount guts series Almost all fields of struct vfsmount are used only by core VFS (and a fairly small part of it, at that). The plan: embed struct vfsmount into struct mount, making the latter visible only to core parts of VFS. Then move fields from vfsmount to mount, eventually leaving only mnt_root/mnt_sb/mnt_flags in struct vfsmount. Filesystem code still gets pointers to struct vfsmount and remains unchanged; all such pointers go to struct vfsmount embedded into the instances of struct mount allocated by fs/namespace.c. When fs/namespace.c et.al. get a pointer to vfsmount, they turn it into pointer to mount (using container_of) and work with that. This is the first part of series; struct mount is introduced, allocation switched to using it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-23 12:14:10 -05:00
vfs: the first spoils - mnt_hash moved taken out of struct vfsmount into struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-24 21:01:32 -05:00
vfs: now it can be done - make mnt_parent point to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-24 22:19:58 -05:00
vfs: move mnt_mountpoint to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-24 22:25:07 -05:00
vfs: start hiding vfsmount guts series Almost all fields of struct vfsmount are used only by core VFS (and a fairly small part of it, at that). The plan: embed struct vfsmount into struct mount, making the latter visible only to core parts of VFS. Then move fields from vfsmount to mount, eventually leaving only mnt_root/mnt_sb/mnt_flags in struct vfsmount. Filesystem code still gets pointers to struct vfsmount and remains unchanged; all such pointers go to struct vfsmount embedded into the instances of struct mount allocated by fs/namespace.c. When fs/namespace.c et.al. get a pointer to vfsmount, they turn it into pointer to mount (using container_of) and work with that. This is the first part of series; struct mount is introduced, allocation switched to using it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-23 12:14:10 -05:00
vfs: all counters taken to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-24 22:53:09 -05:00
vfs: take mnt_child/mnt_mounts to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-24 23:24:33 -05:00
vfs: keep list of mounts for each superblock Keep track of vfsmounts belonging to a superblock. List is protected by vfsmount_lock. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-21 12:11:30 +01:00
vfs: move mnt_devname Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 02:25:17 -05:00
vfs: move mnt_list to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 02:19:55 -05:00
vfs: take mnt_share/mnt_slave/mnt_slave_list and mnt_expire to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 00:22:05 -05:00
vfs: and now we can make ->mnt_master point to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 00:10:28 -05:00
vfs: mnt_ns moved to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 00:46:35 -05:00
vfs: move fsnotify junk to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 02:35:16 -05:00
vfs: mnt_id/mnt_group_id moved Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 00:50:41 -05:00
vfs: move the rest of int fields to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 00:57:42 -05:00
vfs: start hiding vfsmount guts series Almost all fields of struct vfsmount are used only by core VFS (and a fairly small part of it, at that). The plan: embed struct vfsmount into struct mount, making the latter visible only to core parts of VFS. Then move fields from vfsmount to mount, eventually leaving only mnt_root/mnt_sb/mnt_flags in struct vfsmount. Filesystem code still gets pointers to struct vfsmount and remains unchanged; all such pointers go to struct vfsmount embedded into the instances of struct mount allocated by fs/namespace.c. When fs/namespace.c et.al. get a pointer to vfsmount, they turn it into pointer to mount (using container_of) and work with that. This is the first part of series; struct mount is introduced, allocation switched to using it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-23 12:14:10 -05:00
get rid of ->mnt_longterm it's enough to set ->mnt_ns of internal vfsmounts to something distinct from all struct mnt_namespace out there; then we can just use the check for ->mnt_ns != NULL in the fast path of mntput_no_expire() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-09 00:59:08 -04:00
vfs: start hiding vfsmount guts series Almost all fields of struct vfsmount are used only by core VFS (and a fairly small part of it, at that). The plan: embed struct vfsmount into struct mount, making the latter visible only to core parts of VFS. Then move fields from vfsmount to mount, eventually leaving only mnt_root/mnt_sb/mnt_flags in struct vfsmount. Filesystem code still gets pointers to struct vfsmount and remains unchanged; all such pointers go to struct vfsmount embedded into the instances of struct mount allocated by fs/namespace.c. When fs/namespace.c et.al. get a pointer to vfsmount, they turn it into pointer to mount (using container_of) and work with that. This is the first part of series; struct mount is introduced, allocation switched to using it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-23 12:14:10 -05:00
vfs: spread struct mount - mnt_has_parent Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-24 21:47:05 -05:00
vfs: new internal helper: mnt_has_parent(mnt) vfsmounts have ->mnt_parent pointing either to a different vfsmount or to itself; it's never NULL and termination condition in loops traversing the tree towards root is mnt == mnt->mnt_parent. At least one place (see the next patch) is confused about what's going on; let's add an explicit helper checking it right way and use it in all places where we need it. Not that there had been too many, but... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-23 19:26:23 -05:00
vfs: now it can be done - make mnt_parent point to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-24 22:19:58 -05:00
vfs: new internal helper: mnt_has_parent(mnt) vfsmounts have ->mnt_parent pointing either to a different vfsmount or to itself; it's never NULL and termination condition in loops traversing the tree towards root is mnt == mnt->mnt_parent. At least one place (see the next patch) is confused about what's going on; let's add an explicit helper checking it right way and use it in all places where we need it. Not that there had been too many, but... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-23 19:26:23 -05:00
vfs: spread struct mount - __lookup_mnt() result switch __lookup_mnt() to returning struct mount *; callers adjusted. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-24 18:22:03 -05:00
get rid of ->mnt_longterm it's enough to set ->mnt_ns of internal vfsmounts to something distinct from all struct mnt_namespace out there; then we can just use the check for ->mnt_ns != NULL in the fast path of mntput_no_expire() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-09 00:59:08 -04:00
vfs: spread struct mount - __lookup_mnt() result switch __lookup_mnt() to returning struct mount *; callers adjusted. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-24 18:22:03 -05:00
vfs: take /proc/*/mounts and friends to fs/proc_namespace.c rationale: that stuff is far tighter bound to fs/namespace.c than to the guts of procfs proper. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-06 12:21:54 -05:00
get rid of magic in proc_namespace.c don't rely on proc_mounts->m being the first field; container_of() is there for purpose. No need to bother with ->private, while we are at it - the same container_of will do nicely. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-09 01:16:59 -04:00
vfs: take /proc/*/mounts and friends to fs/proc_namespace.c rationale: that stuff is far tighter bound to fs/namespace.c than to the guts of procfs proper. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-06 12:21:54 -05:00
get rid of magic in proc_namespace.c don't rely on proc_mounts->m being the first field; container_of() is there for purpose. No need to bother with ->private, while we are at it - the same container_of will do nicely. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-09 01:16:59 -04:00
vfs: take /proc/*/mounts and friends to fs/proc_namespace.c rationale: that stuff is far tighter bound to fs/namespace.c than to the guts of procfs proper. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-06 12:21:54 -05:00