linux-stable/fs
Ian Kent c72305b547 autofs4: indirect dentry must almost always be positive
We have been seeing mount requests comming to the automount daemon for
keys of the form "<map key>/<non key directory>" which are lookups for
invalid map keys.  But we can check for this in the kernel module and
return a fail immediately, without having to send a request to the daemon.

It is possible to recognise these requests are invalid based on whether
the request dentry is negative and its relation to the autofs file system
root.

For example, given the indirect multi-mount map entry:

idm1  \
    /mm1  <server>:/<path1>
    /mm2  <server>:/<path2>

For a request to mount idm1, IS_ROOT((idm1)->d_parent) will be always be
true and the dentry may be negative.  But directories idm1/mm1 and
idm1/mm2 will always be created as part of the mount request for idm1.  So
any mount request within idm1 itself must have a positive dentry otherwise
the map key is invalid.

In version 4 these multi-mount entries are all mounted and umounted as a
single request and in version 5 the directories idm1/mm1 and idm1/mm2 are
created and an autofs fs mounted on them to act as a mount trigger so the
above is also true.

This also holds true for the autofs version 4 pseudo direct mount feature.
 When this feature is used without the "--ghost" option automount(8) will
create internal submounts as we go down the map key paths which are
essentially normal indirect mounts for which the above holds.  If the
"--ghost" option is given the directories for map keys are created at
daemon startup so valid map entries correspond to postive dentries in the
autofs fs.

autofs version 5 direct mount maps are similar except that the IS_ROOT
check is not needed.  This has been addressed in a previous patch tittled
"autofs4 - detect invalid direct mount requests".

For example, given the direct multi-mount map entry:

/test/dm1  \
    /mm1  <server>:/<path1>
    /mm2  <server>:/<path2>

An autofs fs is mounted on /test/dm1 as a trigger mount and when a mount
is triggered for /test/dm1, the multi-mount offset directories
/test/dm1/mm1 and /test/dm1/mm2 are created and an autofs fs is mounted on
them to act as mount triggers.  So valid direct mount requests must always
have a positive dentry if they correspond to a valid map entry.

Signed-off-by: Ian Kent <raven@themaw.net>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:32 -07:00
..
9p 9p: fix O_APPEND in legacy mode 2008-07-03 09:59:03 -05:00
adfs fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
affs [PATCH] fix reservation discarding in affs 2008-05-06 13:45:33 -04:00
afs Fix various old email addresses for dwmw2 2008-06-06 11:29:10 -07:00
autofs
autofs4 autofs4: indirect dentry must almost always be positive 2008-07-24 10:47:32 -07:00
befs byteorder: don't directly include linux/byteorder/generic.h 2008-05-16 12:01:45 -07:00
bfs fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
cifs Merge commit 'v2.6.26' into bkl-removal 2008-07-14 15:29:34 -06:00
coda device create: coda: convert device_create to device_create_drvdata 2008-07-21 21:54:41 -07:00
configfs configfs: Allow ->make_item() and ->make_group() to return detailed errors. 2008-07-17 15:21:29 -07:00
cramfs fs: Remove unnecessary inclusions of asm/semaphore.h 2008-04-18 22:16:44 -04:00
debugfs debugfs: Implement debugfs_remove_recursive() 2008-07-21 21:54:59 -07:00
devpts devpts: factor out PTY index allocation 2008-04-30 08:29:48 -07:00
dlm configfs: Allow ->make_item() and ->make_group() to return detailed errors. 2008-07-17 15:21:29 -07:00
ecryptfs eCryptfs: Make all persistent file opens delayed 2008-07-24 10:47:31 -07:00
efs efs: update error msg to not refer to deleted read_inode() 2008-04-02 15:28:19 -07:00
exportfs fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
ext2 ext2: retry block allocation if new blocks are allocated from system zone 2008-04-28 08:58:43 -07:00
ext3 ext3: add missing unlock to error path in ext3_quota_write() 2008-07-04 10:40:05 -07:00
ext4 ext4: do not set extents feature from the kernel 2008-07-11 19:27:31 -04:00
fat Merge commit 'v2.6.26' into bkl-removal 2008-07-14 15:29:34 -06:00
freevxfs fs/freevxfs/: proper externs 2008-04-29 08:06:00 -07:00
fuse fuse: fix thinko in max I/O size calucation 2008-06-17 18:08:10 -07:00
gfs2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw 2008-07-15 10:38:46 -07:00
hfs hfs: fix warning with 64k PAGE_SIZE 2008-04-30 08:29:52 -07:00
hfsplus Fix hfsplus oops on image without extents 2008-05-13 08:02:24 -07:00
hostfs
hpfs
hppfs fix hppfs Makefile breakage 2008-05-21 16:55:58 -07:00
hugetlbfs hugetlbfs: per mount huge page sizes 2008-07-24 10:47:17 -07:00
isofs isofs: fix access to unallocated memory when reading corrupted filesystem 2008-04-30 08:29:33 -07:00
jbd jbd: need to hold j_state_lock to updates to transaction t_state to T_COMMIT 2008-05-14 19:11:14 -07:00
jbd2 ext4: Add ordered mode support for delalloc 2008-07-11 19:27:31 -04:00
jffs2 Merge git://git.infradead.org/mtd-2.6 2008-05-01 11:15:28 -07:00
jfs jfs: remove DIRENTSIZ 2008-06-10 15:12:58 -05:00
lockd Merge branch 'for-2.6.27' of git://linux-nfs.org/~bfields/linux 2008-07-20 21:21:46 -07:00
minix
msdos Replace BKL with superblock lock in fat/msdos/vfat 2008-06-20 14:05:54 -06:00
ncpfs Remove BKL from remote_llseek v2 2008-07-02 15:06:27 -06:00
nfs Merge branch 'bkl-removal' into next 2008-07-15 18:34:58 -04:00
nfs_common
nfsd Merge branch 'for-2.6.27' of git://linux-nfs.org/~bfields/linux 2008-07-20 21:21:46 -07:00
nls
ntfs ntfs: le*_add_cpu conversion 2008-05-24 09:56:08 -07:00
ocfs2 configfs: Allow ->make_item() and ->make_group() to return detailed errors. 2008-07-17 15:21:29 -07:00
openpromfs
partitions driver core: remove KOBJ_NAME_LEN define 2008-07-21 21:54:52 -07:00
proc vmallocinfo: add NUMA information 2008-07-24 10:47:17 -07:00
qnx4
ramfs ramfs: enable splice write 2008-07-04 09:52:14 +02:00
reiserfs reiserfs: discard prealloc in reiserfs_delete_inode 2008-07-08 12:39:31 -07:00
romfs
smbfs Remove BKL from remote_llseek v2 2008-07-02 15:06:27 -06:00
sysfs driver core: Suppress sysfs warnings for device_rename(). 2008-07-21 21:55:01 -07:00
sysv sysv: [bl]e*_add_cpu conversion 2008-04-30 08:29:52 -07:00
ubifs UBIFS: include to compilation 2008-07-15 17:35:24 +03:00
udf udf: Fix regression in UDF anchor block detection 2008-06-24 11:38:03 +02:00
ufs ufs: remove unneeded ufs_put_inode prototype 2008-05-13 08:02:23 -07:00
vfat Replace BKL with superblock lock in fat/msdos/vfat 2008-06-20 14:05:54 -06:00
xfs Fix reference counting race on log buffers 2008-07-11 11:37:18 -07:00
aio.c uml: activate_mm: remove the dead PF_BORROWED_MM check 2008-06-06 11:36:22 -07:00
anon_inodes.c flag parameters: NONBLOCK in anon_inode_getfd 2008-07-24 10:47:28 -07:00
attr.c
bad_inode.c
binfmt_aout.c fs/binfmt_aout.c: use printk_ratelimit() 2008-04-29 08:06:04 -07:00
binfmt_elf.c execve filename: document and export via auxiliary vector 2008-07-22 09:59:40 -07:00
binfmt_elf_fdpic.c nommu: fix ksize() abuse 2008-06-06 11:29:13 -07:00
binfmt_em86.c binfmt_misc.c: avoid potential kernel stack overflow 2008-04-29 08:06:04 -07:00
binfmt_flat.c nommu: fix ksize() abuse 2008-06-06 11:29:13 -07:00
binfmt_misc.c binfmt_misc: use simple_read_from_buffer() 2008-07-24 10:47:27 -07:00
binfmt_script.c binfmt_misc.c: avoid potential kernel stack overflow 2008-04-29 08:06:04 -07:00
binfmt_som.c [PATCH] sanitize handling of shared descriptor tables in failing execve() 2008-04-25 09:23:53 -04:00
bio-integrity.c block: integrity checkpatch cleanups 2008-07-03 13:21:13 +02:00
bio.c Add bvec_merge_data to handle stacked devices and ->merge_bvec() 2008-07-03 13:21:15 +02:00
block_dev.c [PATCH] fix cgroup-inflicted breakage in block_dev.c 2008-06-23 08:30:55 -04:00
buffer.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
char_dev.c Remove the lock_kernel() call from chrdev_open() 2008-06-20 14:05:53 -06:00
compat.c flag parameters: signalfd 2008-07-24 10:47:27 -07:00
compat_binfmt_elf.c
compat_ioctl.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/holtmann/bluetooth-2.6 2008-07-19 00:30:39 -07:00
dcache.c fix soft lock up at NFS mount via per-SB LRU-list of unused dentries 2008-07-24 10:47:15 -07:00
dcookies.c
direct-io.c
dnotify.c [PATCH] split linux/file.h 2008-05-01 13:08:16 -04:00
dquot.c quota: don't call sync_fs() from vfs_quota_off() when there's no quota turn off 2008-05-13 08:02:23 -07:00
drop_caches.c vfs: skip inodes without pages to free in drop_pagecache_sb() 2008-04-29 08:06:05 -07:00
eventfd.c flag parameters: check magic constants 2008-07-24 10:47:29 -07:00
eventpoll.c flag parameters add-on: remove epoll_create size param 2008-07-24 10:47:29 -07:00
exec.c mm: remove double indirection on tlb parameter to free_pgd_range() & Co 2008-07-24 10:47:15 -07:00
fcntl.c flag parameters: dup2 2008-07-24 10:47:28 -07:00
fifo.c
file.c [PATCH] avoid multiplication overflows and signedness issues for max_fds 2008-05-16 17:22:52 -04:00
file_table.c [PATCH] split linux/file.h 2008-05-01 13:08:16 -04:00
filesystems.c
fs-writeback.c VFS: export sync_sb_inodes 2008-07-14 19:10:52 +03:00
generic_acl.c
inode.c VFS: fix unused variable warning 2008-05-06 13:13:37 -07:00
inotify.c
inotify_user.c flag parameters: check magic constants 2008-07-24 10:47:29 -07:00
internal.h [PATCH] move a bunch of declarations to fs/internal.h 2008-04-21 23:11:01 -04:00
ioctl.c make vfs_ioctl() static 2008-04-29 08:06:00 -07:00
ioprio.c
Kconfig Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2 2008-07-17 10:55:51 -07:00
Kconfig.binfmt frv: don't offer BINFMT_FLAT 2008-06-06 11:29:08 -07:00
libfs.c add kernel-doc for simple_read_from_buffer and memory_read_from_buffer 2008-07-04 10:40:07 -07:00
locks.c [patch 4/4] flock: remove unused fields from file_lock_operations 2008-06-23 11:52:30 -04:00
Makefile Merge branch 'for_linus' of git://git.infradead.org/~dedekind/ubifs-2.6 2008-07-16 15:02:57 -07:00
mbcache.c vfs: fix possible deadlock in ext2, ext3, ext4 when using xattrs 2008-04-15 19:35:41 -07:00
mpage.c vfs: add hooks for ext4's delayed allocation support 2008-07-11 19:27:31 -04:00
namei.c [patch 3/4] vfs: fix ERR_PTR abuse in generic_readlink 2008-06-23 11:52:30 -04:00
namespace.c LSM/SELinux: show LSM mount options in /proc/mounts 2008-07-14 15:02:05 +10:00
nfsctl.c
no-block.c
open.c fs: check for statfs overflow 2008-07-24 10:47:19 -07:00
pipe.c flag parameters: NONBLOCK in pipe 2008-07-24 10:47:29 -07:00
pnode.c [patch 7/7] vfs: mountinfo: show dominating group id 2008-04-23 00:05:09 -04:00
pnode.h [patch 7/7] vfs: mountinfo: show dominating group id 2008-04-23 00:05:09 -04:00
posix_acl.c
quota.c quota: quota core changes for quotaon on remount 2008-04-28 08:58:33 -07:00
quota_v1.c quota: do not allow setting of quota limits to too high values 2008-04-28 08:58:32 -07:00
quota_v2.c quota: le*_add_cpu conversion 2008-04-30 08:29:51 -07:00
read_write.c Remove BKL from remote_llseek v2 2008-07-02 15:06:27 -06:00
read_write.h
readdir.c
select.c Fix performance regression on lmbench select benchmark 2008-06-22 12:23:15 -07:00
seq_file.c [patch 2/7] vfs: mountinfo: add seq_file_root() 2008-04-23 00:04:38 -04:00
signalfd.c flag parameters: check magic constants 2008-07-24 10:47:29 -07:00
splice.c splice: fix generic_file_splice_read() race with page invalidation 2008-07-04 09:52:14 +02:00
stack.c
stat.c
super.c fix soft lock up at NFS mount via per-SB LRU-list of unused dentries 2008-07-24 10:47:15 -07:00
sync.c SYNC_FILE_RANGE_WRITE may and will block. Document that. 2008-07-24 10:47:17 -07:00
timerfd.c flag parameters: check magic constants 2008-07-24 10:47:29 -07:00
utimes.c [patch for 2.6.26 4/4] vfs: utimensat(): fix write access check for futimens() 2008-06-23 08:43:52 -04:00
xattr.c xattr: add missing consts to function arguments 2008-04-29 08:06:06 -07:00
xattr_acl.c