15 Nov, 2012
1 commit
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Use kuid_t and kgid_t in struct autofs_info and struct autofs_wait_queue.
When creating directories and symlinks default the uid and gid of
the mount requester to the global root uid and gid. autofs4_wait
will update these fields when a mount is requested.When generating autofsv5 packets report the uid and gid of the mount
requestor in user namespace of the process that opened the pipe,
reporting unmapped uids and gids as overflowuid and overflowgid.In autofs_dev_ioctl_requester return the uid and gid of the last mount
requester converted into the calling processes user namespace. When the
uid or gid don't map return overflowuid and overflowgid as appropriate,
allowing failure to find a mount requester to be distinguished from
failure to map a mount requester.The uid and gid mount options specifying the user and group of the
root autofs inode are converted into kuid and kgid as they are parsed
defaulting to the current uid and current gid of the process that
mounts autofs.Mounting of autofs for the present remains confined to processes in
the initial user namespace.Cc: Ian Kent
Acked-by: Serge Hallyn
Signed-off-by: Eric W. Biederman
29 May, 2012
1 commit
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Pull writeback tree from Wu Fengguang:
"Mainly from Jan Kara to avoid iput() in the flusher threads."* tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
writeback: Avoid iput() from flusher thread
vfs: Rename end_writeback() to clear_inode()
vfs: Move waiting for inode writeback from end_writeback() to evict_inode()
writeback: Refactor writeback_single_inode()
writeback: Remove wb->list_lock from writeback_single_inode()
writeback: Separate inode requeueing after writeback
writeback: Move I_DIRTY_PAGES handling
writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()
writeback: Move clearing of I_SYNC into inode_sync_complete()
writeback: initialize global_dirty_limit
fs: remove 8 bytes of padding from struct writeback_control on 64 bit builds
mm: page-writeback.c: local functions should not be exposed globally
06 May, 2012
1 commit
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After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.Signed-off-by: Jan Kara
Signed-off-by: Fengguang Wu
30 Apr, 2012
1 commit
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The autofs packet size has had a very unfortunate size problem on x86:
because the alignment of 'u64' differs in 32-bit and 64-bit modes, and
because the packet data was not 8-byte aligned, the size of the autofsv5
packet structure differed between 32-bit and 64-bit modes despite
looking otherwise identical (300 vs 304 bytes respectively).We first fixed that up by making the 64-bit compat mode know about this
problem in commit a32744d4abae ("autofs: work around unhappy compat
problem on x86-64"), and that made a 32-bit 'systemd' work happily on a
64-bit kernel because everything then worked the same way as on a 32-bit
kernel.But it turned out that 'automount' had actually known and worked around
this problem in user space, so fixing the kernel to do the proper 32-bit
compatibility handling actually *broke* 32-bit automount on a 64-bit
kernel, because it knew that the packet sizes were wrong and expected
those incorrect sizes.As a result, we ended up reverting that compatibility mode fix, and
thus breaking systemd again, in commit fcbf94b9dedd.With both automount and systemd doing a single read() system call, and
verifying that they get *exactly* the size they expect but using
different sizes, it seemed that fixing one of them inevitably seemed to
break the other. At one point, a patch I seriously considered applying
from Michael Tokarev did a "strcmp()" to see if it was automount that
was doing the operation. Ugly, ugly.However, a prettier solution exists now thanks to the packetized pipe
mode. By marking the communication pipe as being packetized (by simply
setting the O_DIRECT flag), we can always just write the bigger packet
size, and if user-space does a smaller read, it will just get that
partial end result and the extra alignment padding will simply be thrown
away.This makes both automount and systemd happy, since they now get the size
they asked for, and the kernel side of autofs simply no longer needs to
care - it could pad out the packet arbitrarily.Of course, if there is some *other* user of autofs (please, please,
please tell me it ain't so - and we haven't heard of any) that tries to
read the packets with multiple writes, that other user will now be
broken - the whole point of the packetized mode is that one system call
gets exactly one packet, and you cannot read a packet in pieces.Tested-by: Michael Tokarev
Cc: Alan Cox
Cc: David Miller
Cc: Ian Kent
Cc: Thomas Meyer
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds
28 Apr, 2012
1 commit
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This reverts commit a32744d4abae24572eff7269bc17895c41bd0085.
While that commit was technically the right thing to do, and made the
x86-64 compat mode work identically to native 32-bit mode (and thus
fixing the problem with a 32-bit systemd install on a 64-bit kernel), it
turns out that the automount binaries had workarounds for this compat
problem.Now, the workarounds are disgusting: doing an "uname()" to find out the
architecture of the kernel, and then comparing it for the 64-bit cases
and fixing up the size of the read() in automount for those. And they
were confused: it's not actually a generic 64-bit issue at all, it's
very much tied to just x86-64, which has different alignment for an
'u64' in 64-bit mode than in 32-bit mode.But the end result is that fixing the compat layer actually breaks the
case of a 32-bit automount on a x86-64 kernel.There are various approaches to fix this (including just doing a
"strcmp()" on current->comm and comparing it to "automount"), but I
think that I will do the one that teaches pipes about a special "packet
mode", which will allow user space to not have to care too deeply about
the padding at the end of the autofs packet.That change will make the compat workaround unnecessary, so let's revert
it first, and get automount working again in compat mode. The
packetized pipes will then fix autofs for systemd.Reported-and-requested-by: Michael Tokarev
Cc: Ian Kent
Cc: stable@kernel.org # for 3.3
Signed-off-by: Linus Torvalds
21 Mar, 2012
1 commit
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Signed-off-by: Al Viro
26 Feb, 2012
1 commit
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When the autofs protocol version 5 packet type was added in commit
5c0a32fc2cd0 ("autofs4: add new packet type for v5 communications"), it
obvously tried quite hard to be word-size agnostic, and uses explicitly
sized fields that are all correctly aligned.However, with the final "char name[NAME_MAX+1]" array at the end, the
actual size of the structure ends up being not very well defined:
because the struct isn't marked 'packed', doing a "sizeof()" on it will
align the size of the struct up to the biggest alignment of the members
it has.And despite all the members being the same, the alignment of them is
different: a "__u64" has 4-byte alignment on x86-32, but native 8-byte
alignment on x86-64. And while 'NAME_MAX+1' ends up being a nice round
number (256), the name[] array starts out a 4-byte aligned.End result: the "packed" size of the structure is 300 bytes: 4-byte, but
not 8-byte aligned.As a result, despite all the fields being in the same place on all
architectures, sizeof() will round up that size to 304 bytes on
architectures that have 8-byte alignment for u64.Note that this is *not* a problem for 32-bit compat mode on POWER, since
there __u64 is 8-byte aligned even in 32-bit mode. But on x86, 32-bit
and 64-bit alignment is different for 64-bit entities, and as a result
the structure that has exactly the same layout has different sizes.So on x86-64, but no other architecture, we will just subtract 4 from
the size of the structure when running in a compat task. That way we
will write the properly sized packet that user mode expects.Not pretty. Sadly, this very subtle, and unnecessary, size difference
has been encoded in user space that wants to read packets of *exactly*
the right size, and will refuse to touch anything else.Reported-and-tested-by: Thomas Meyer
Signed-off-by: Ian Kent
Signed-off-by: Linus Torvalds
11 Jan, 2012
1 commit
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Just serialize the actual writing of packets into pipe on
a new mutex, independent from everything else in the locking
hierarchy. As soon as something has started feeding a piece
of packet into the pipe to daemon, we *want* everything else
about to try the same to wait until we are done.Acked-by: Ian Kent
Signed-off-by: Al Viro
07 Jan, 2012
1 commit
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Signed-off-by: Al Viro
04 Jan, 2012
1 commit
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Signed-off-by: Al Viro
02 Nov, 2011
1 commit
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Replace remaining direct i_nlink updates with a new set_nlink()
updater function.Signed-off-by: Miklos Szeredi
Tested-by: Toshiyuki Okajima
Signed-off-by: Christoph Hellwig
18 Jan, 2011
7 commits
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The latter is called only when both ino and dentry are about to
be freed, so cleaning ->d_fsdata and ->dentry is pointless.Acked-by: Ian Kent
Signed-off-by: Al Viro -
split init_ino into new_ino and clean_ino; the former is
what used to be init_ino(NULL, sbi), the latter is for cases
where we passed non-NULL ino. Lose unused arguments.Acked-by: Ian Kent
Signed-off-by: Al Viro -
Acked-by: Ian Kent
Signed-off-by: Al Viro -
It's used only to pass the length of symlink body to
autofs4_get_inode() in autofs4_dir_symlink(). We can
bloody well set inode->i_size in autofs4_dir_symlink()
directly and be done with that.Acked-by: Ian Kent
Signed-off-by: Al Viro -
In all cases we'd set inf->mode to know value just before
passing it to autofs4_get_inode(). That kills the need
to store it in autofs_info and pass it to autofs_init_ino()Acked-by: Ian Kent
Signed-off-by: Al Viro -
Kill it. Mind you, it's been an obfuscated call of autofs4_init_ino()
ever since 2.3.99pre6-4...Acked-by: Ian Kent
Signed-off-by: Al Viro -
gets rid of all ->free()/->u.symlink machinery in autofs; we simply
keep symlink bodies in inode->i_private and free them in ->evict_inode().Acked-by: Ian Kent
Signed-off-by: Al Viro
16 Jan, 2011
6 commits
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Merge the remaining autofs4 dentry ops tables. It doesn't matter if
d_automount and d_manage are present on something that's not mountable or
holdable as these ops are only used if the appropriate flags are set in
dentry->d_flags.[AV] switch to ->s_d_op, since now _everything_ on autofs4 is using the
same dentry_operations.Signed-off-by: David Howells
Signed-off-by: Al Viro -
When this function is called the local reference count does't need to
be updated since the dentry is going away and dput definitely must
not be called here.Also the autofs info struct field inode isn't used so remove it.
Signed-off-by: Ian Kent
Signed-off-by: David Howells
Signed-off-by: Al Viro -
There are now two distinct dentry operations uses. One for dentrys
that trigger mounts and one for dentrys that do not.Rationalize the use of these dentry operations and rename them to
reflect their function.Signed-off-by: Ian Kent
Signed-off-by: David Howells
Signed-off-by: Al Viro -
Since the use of ->follow_link() has been eliminated there is no
need to separate the indirect and direct inode operations.Signed-off-by: Ian Kent
Signed-off-by: David Howells
Signed-off-by: Al Viro -
This patch required a previous patch to add the ->d_automount()
dentry operation.Add a function to use the newly defined ->d_manage() dentry operation
for blocking during mount and expire.Whether the VFS calls the dentry operations d_automount() and d_manage()
is controled by the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags. autofs
uses the d_automount() operation to callback to user space to request
mount operations and the d_manage() operation to block walks into mounts
that are under construction or destruction.In order to prevent these functions from being called unnecessarily the
DMANAGED_* flags are cleared for cases which would cause this. In the
common case the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags are both
set for dentrys waiting to be mounted. The DMANAGED_TRANSIT flag is
cleared upon successful mount request completion and set during expire
runs, both during the dentry expire check, and if selected for expire,
is left set until a subsequent successful mount request completes.The exception to this is the so-called rootless multi-mount which has
no actual mount at its base. In this case the DMANAGED_AUTOMOUNT flag
is cleared upon successful mount request completion as well and set
again after a successful expire.Signed-off-by: Ian Kent
Signed-off-by: David Howells
Signed-off-by: Al Viro -
Add a function to use the newly defined ->d_automount() dentry operation
for triggering mounts instead of doing the user space callback in ->lookup()
and ->d_revalidate().Note, to be useful the subsequent patch to add the ->d_manage() dentry
operation is also needed so the discussion of functionality is deferred to
that patch.Signed-off-by: Ian Kent
Signed-off-by: David Howells
Signed-off-by: Al Viro
07 Jan, 2011
1 commit
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Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.Patched with:
git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
Signed-off-by: Nick Piggin
26 Oct, 2010
1 commit
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Instead of always assigning an increasing inode number in new_inode
move the call to assign it into those callers that actually need it.
For now callers that need it is estimated conservatively, that is
the call is added to all filesystems that do not assign an i_ino
by themselves. For a few more filesystems we can avoid assigning
any inode number given that they aren't user visible, and for others
it could be done lazily when an inode number is actually needed,
but that's left for later patches.Signed-off-by: Christoph Hellwig
Signed-off-by: Dave Chinner
Signed-off-by: Al Viro
04 Mar, 2010
2 commits
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... and get rid of open-coding its guts (i.e. RIP autofs4_force_release())
Signed-off-by: Al Viro
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This reverts commit 213614d583748d00967a91cacd656f417efb36ce.
Alas, ->d_revalidate() can't rely on ->lookup() finishing what
it's started; if d_alloc() in do_lookup() fails, we are not going
to call ->lookup() at all.Signed-off-by: Al Viro
16 Dec, 2009
2 commits
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We need to be able to cope with the directory mutex being held during
->d_revalidate() in some cases, but not all cases, and not necessarily by
us. Because we need to release the mutex when we call back to the daemon
to do perform a mount we must be sure that it is us who holds the mutex so
we must redirect mount requests to ->lookup() if the mutex is held.Signed-off-by: Ian Kent
Cc: Sage Weil
Cc: Al Viro
Cc: Andreas Dilger
Cc: Christoph Hellwig
Cc: Yehuda Saheh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Define some simple helper functions for adding and deleting entries on the
active (and unhashed) dentry list.Signed-off-by: Ian Kent
Cc: Sage Weil
Cc: Al Viro
Cc: Andreas Dilger
Cc: Christoph Hellwig
Cc: Yehuda Saheh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Mar, 2009
1 commit
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Signed-off-by: Al Viro
07 Jan, 2009
1 commit
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- the type assigned at mount when no type is given is changed
from 0 to AUTOFS_TYPE_INDIRECT. This was done because 0 and
AUTOFS_TYPE_INDIRECT were being treated implicitly as the same
type.- previously, an offset mount had it's type set to
AUTOFS_TYPE_DIRECT|AUTOFS_TYPE_OFFSET but the mount control
re-implementation needs to be able distinguish all three types.
So this was changed to make the type setting explicit.- a type AUTOFS_TYPE_ANY was added for use by the re-implementation
when checking if a given path is a mountpoint. It's not really a
type as we use this to ask if a given path is a mountpoint in the
autofs_dev_ioctl_ismountpoint() function.- functions to set and test the autofs mount types have been added to
improve readability and make the type usage explicit.- the mount type is used from user space for the mount control
re-implementtion so, for consistency, all the definitions have
been moved to the user space include file include/linux/auto_fs4.h.Signed-off-by: Ian Kent
Signed-off-by: Jeff Moyer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Jan, 2009
1 commit
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... and don't bother in callers. Don't bother with zeroing i_blocks,
while we are at it - it's already been zeroed.i_mode is not worth the effort; it has no common default value.
Signed-off-by: Al Viro
14 Nov, 2008
1 commit
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Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().
Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.Signed-off-by: David Howells
Reviewed-by: James Morris
Acked-by: Serge Hallyn
Cc: Ian Kent
Cc: autofs@linux.kernel.org
Signed-off-by: James Morris
17 Oct, 2008
2 commits
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Track the uid and gid of the last process to request a mount for on an
autofs dentry.[akpm@linux-foundation.org: fix tpyo in comment]
Signed-off-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Usage of the AUTOFS_TYPE_* defines is a little confusing and appears
inconsistent.Signed-off-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Oct, 2008
1 commit
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This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.This was posted for review some time ago and I believe its been in -mm
since then.Signed-off-by: Steven Whitehouse
Cc: Alexander Viro
Signed-off-by: Linus Torvalds
25 Jul, 2008
3 commits
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The autofs4_catatonic_mode() function accesses the wait queue without any
locking but can be called at any time. This could lead to a possible
double free of the name field of the wait and a double fput of the daemon
communication pipe or an fput of a NULL file pointer.Signed-off-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
A while ago a patch to resolve a deadlock during directory creation was
merged. This delayed the hashing of lookup dentrys until the ->mkdir()
(or ->symlink()) operation completed to ensure we always went through
->lookup() instead of also having processes go through ->revalidate() so
our VFS locking remained consistent.Now we are seeing a couple of side affects of that change in situations
with heavy mount activity.Two cases have been identified:
1) When a mount request is triggered, due to the delayed hashing, the
directory created by user space for the mount point doesn't have the
DCACHE_AUTOFS_PENDING flag set. In the case of an autofs multi-mount
where a tree of mount point directories are created this can lead to
the path walk continuing rather than the dentry being sent to the wait
queue to wait for request completion. This is because, if the pending
flag isn't set, the criteria for deciding this is a mount in progress
fails to hold, namely that the dentry is not a mount point and has no
subdirectories.2) A mount request dentry is initially created negative and unhashed.
It remains this way until the ->mkdir() callback completes. Since it
is unhashed a fresh dentry is used when the user space mount request
creates the mount point directory. This leaves the original dentry
negative and unhashed. But revalidate has no way to tell the VFS that
the dentry has changed, other than to force another ->lookup() by
returning false, which is at best wastefull and at worst not possible.
This results in an -ENOENT return from the original path walk when in
fact the mount succeeded.To resolve this we need to ensure that the same dentry is used in all
calls to ->lookup() during the course of a mount request. This patch
achieves that by adding the initial dentry to a look aside list and
removes it at ->mkdir() or ->symlink() completion (or when the dentry is
released), since these are the only create operations autofs4 supports.Signed-off-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Correct the error of making a positive dentry negative after it has been
instantiated.The code that makes this error attempts to re-use the dentry from a
concurrent expire and mount to resolve a race and the dentry used for the
lookup must be negative for mounts to trigger in the required cases. The
fact is that the dentry doesn't need to be re-used because all that is
needed is to preserve the flag that indicates an expire is still
incomplete at the time of the mount request.This change uses the the dentry to check the flag and wait for the expire
to complete then discards it instead of attempting to re-use it.Signed-off-by: Ian Kent
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds