Skip to content

R
raspberrypi-kernel

openeuler / raspberrypi-kernel

通知 13
Star 1
Fork 0
R
raspberrypi-kernel
切换分支/标签
  1. 12 5月, 2009 1 次提交
  3. 21 4月, 2009 1 次提交
    • D
      Fix i_mutex vs. readdir handling in nfsd · 2f9092e1
      由 David Woodhouse 提交于 
      Commit 14f7dd63 ("Copy XFS readdir hack into nfsd code") introduced a
bug to generic code which had been extant for a long time in the XFS
version -- it started to call through into lookup_one_len() and hence
into the file systems' ->lookup() methods without i_mutex held on the
directory.

This patch fixes it by locking the directory's i_mutex again before
calling the filldir functions. The original deadlocks which commit
14f7dd63 was designed to avoid are still avoided, because they were due
to fs-internal locking, not i_mutex.

While we're at it, fix the return type of nfsd_buffered_readdir() which
should be a __be32 not an int -- it's an NFS errno, not a Linux errno.
And return nfserrno(-ENOMEM) when allocation fails, not just -ENOMEM.
Sparse would have caught that, if it wasn't so busy bitching about
__cold__.

Commit 05f4f678 ("nfsd4: don't do lookup within readdir in recovery
code") introduced a similar problem with calling lookup_one_len()
without i_mutex, which this patch also addresses. To fix that, it was
necessary to fix the called functions so that they expect i_mutex to be
held; that part was done by J. Bruce Fields.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Umm-I-can-live-with-that-by: NAl Viro <viro@zeniv.linux.org.uk>
Reported-by: NJ. R. Okajima <hooanon05@yahoo.co.jp>
Tested-by: NJ. Bruce Fields <bfields@citi.umich.edu>
LKML-Reference: <8036.1237474444@jrobl>
Cc: stable@kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      2f9092e1
  5. 04 4月, 2009 1 次提交
  7. 19 3月, 2009 1 次提交
  9. 07 1月, 2009 1 次提交
  11. 25 11月, 2008 1 次提交
    • J
      nfsd: use of unitialized list head on error exit in nfs4recover.c · e4625eb8
      由 J. Bruce Fields 提交于 
      Thanks to Matthew Dodd for this bug report:

A file label issue while running SELinux in MLS mode provoked the
following bug, which is a result of use before init on a 'struct list_head'.

In nfsd4_list_rec_dir() if the call to dentry_open() fails the 'goto
out' skips INIT_LIST_HEAD() which results in the normally improbable
case where list_entry() returns NULL.

Trace follows.

NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
SELinux:  Context unconfined_t:object_r:var_lib_nfs_t:s0 is not valid
(left unmapped).
type=1400 audit(1227298063.609:282): avc:  denied  { read } for
pid=1890 comm="rpc.nfsd" name="v4recovery" dev=dm-0 ino=148726
scontext=system_u:system_r:nfsd_t:s0-s15:c0.c1023
tcontext=system_u:object_r:unlabeled_t:s15:c0.c1023 tclass=dir
BUG: unable to handle kernel NULL pointer dereference at 00000004
IP: [<c050894e>] list_del+0x6/0x60
*pde = 0d9ce067 *pte = 00000000
Oops: 0000 [#1] SMP
Modules linked in: nfsd lockd nfs_acl auth_rpcgss exportfs autofs4
sunrpc ipv6 dm_multipath scsi_dh ppdev parport_pc sg parport floppy
ata_piix pata_acpi ata_generic libata pcnet32 i2c_piix4 mii pcspkr
i2c_core dm_snapshot dm_zero dm_mirror dm_log dm_mod BusLogic sd_mod
scsi_mod crc_t10dif ext3 jbd mbcache uhci_hcd ohci_hcd ehci_hcd [last
unloaded: microcode]

Pid: 1890, comm: rpc.nfsd Not tainted (2.6.27.5-37.fc9.i686 #1)
EIP: 0060:[<c050894e>] EFLAGS: 00010217 CPU: 0
EIP is at list_del+0x6/0x60
EAX: 00000000 EBX: 00000000 ECX: 00000000 EDX: cd99e480
ESI: cf9caed8 EDI: 00000000 EBP: cf9caebc ESP: cf9caeb8
  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process rpc.nfsd (pid: 1890, ti=cf9ca000 task=cf4de580 task.ti=cf9ca000)
Stack: 00000000 cf9caef0 d0a9f139 c0496d04 d0a9f217 fffffff3 00000000
00000000
        00000000 00000000 cf32b220 00000000 00000008 00000801 cf9caefc
d0a9f193
        00000000 cf9caf08 d0a9b6ea 00000000 cf9caf1c d0a874f2 cf9c3004
00000008
Call Trace:
  [<d0a9f139>] ? nfsd4_list_rec_dir+0xf3/0x13a [nfsd]
  [<c0496d04>] ? do_path_lookup+0x12d/0x175
  [<d0a9f217>] ? load_recdir+0x0/0x26 [nfsd]
  [<d0a9f193>] ? nfsd4_recdir_load+0x13/0x34 [nfsd]
  [<d0a9b6ea>] ? nfs4_state_start+0x2a/0xc5 [nfsd]
  [<d0a874f2>] ? nfsd_svc+0x51/0xff [nfsd]
  [<d0a87f2d>] ? write_svc+0x0/0x1e [nfsd]
  [<d0a87f48>] ? write_svc+0x1b/0x1e [nfsd]
  [<d0a87854>] ? nfsctl_transaction_write+0x3a/0x61 [nfsd]
  [<c04b6a4e>] ? sys_nfsservctl+0x116/0x154
  [<c04975c1>] ? putname+0x24/0x2f
  [<c04975c1>] ? putname+0x24/0x2f
  [<c048d49f>] ? do_sys_open+0xad/0xb7
  [<c048d337>] ? filp_close+0x50/0x5a
  [<c048d4eb>] ? sys_open+0x1e/0x26
  [<c0403cca>] ? syscall_call+0x7/0xb
  [<c064007b>] ? init_cyrix+0x185/0x490
  =======================
Code: 75 e1 8b 53 08 8d 4b 04 8d 46 04 e8 75 00 00 00 8b 53 10 8d 4b 0c
8d 46 0c e8 67 00 00 00 5b 5e 5f 5d c3 90 90 55 89 e5 53 89 c3 <8b> 40
04 8b 00 39 d8 74 16 50 53 68 3e d6 6f c0 6a 30 68 78 d6
EIP: [<c050894e>] list_del+0x6/0x60 SS:ESP 0068:cf9caeb8
---[ end trace a89c4ad091c4ad53 ]---

Cc: Matthew N. Dodd <Matthew.Dodd@spart.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
      e4625eb8
  13. 14 11月, 2008 3 次提交
    • D
      CRED: Inaugurate COW credentials · d84f4f99
      由 David Howells 提交于 
      Inaugurate copy-on-write credentials management.  This uses RCU to manage the
credentials pointer in the task_struct with respect to accesses by other tasks.
A process may only modify its own credentials, and so does not need locking to
access or modify its own credentials.

A mutex (cred_replace_mutex) is added to the task_struct to control the effect
of PTRACE_ATTACHED on credential calculations, particularly with respect to
execve().

With this patch, the contents of an active credentials struct may not be
changed directly; rather a new set of credentials must be prepared, modified
and committed using something like the following sequence of events:

	struct cred *new = prepare_creds();
	int ret = blah(new);
	if (ret < 0) {
		abort_creds(new);
		return ret;
	}
	return commit_creds(new);

There are some exceptions to this rule: the keyrings pointed to by the active
credentials may be instantiated - keyrings violate the COW rule as managing
COW keyrings is tricky, given that it is possible for a task to directly alter
the keys in a keyring in use by another task.

To help enforce this, various pointers to sets of credentials, such as those in
the task_struct, are declared const.  The purpose of this is compile-time
discouragement of altering credentials through those pointers.  Once a set of
credentials has been made public through one of these pointers, it may not be
modified, except under special circumstances:

  (1) Its reference count may incremented and decremented.

  (2) The keyrings to which it points may be modified, but not replaced.

The only safe way to modify anything else is to create a replacement and commit
using the functions described in Documentation/credentials.txt (which will be
added by a later patch).

This patch and the preceding patches have been tested with the LTP SELinux
testsuite.

This patch makes several logical sets of alteration:

 (1) execve().

     This now prepares and commits credentials in various places in the
     security code rather than altering the current creds directly.

 (2) Temporary credential overrides.

     do_coredump() and sys_faccessat() now prepare their own credentials and
     temporarily override the ones currently on the acting thread, whilst
     preventing interference from other threads by holding cred_replace_mutex
     on the thread being dumped.

     This will be replaced in a future patch by something that hands down the
     credentials directly to the functions being called, rather than altering
     the task's objective credentials.

 (3) LSM interface.

     A number of functions have been changed, added or removed:

     (*) security_capset_check(), ->capset_check()
     (*) security_capset_set(), ->capset_set()

     	 Removed in favour of security_capset().

     (*) security_capset(), ->capset()

     	 New.  This is passed a pointer to the new creds, a pointer to the old
     	 creds and the proposed capability sets.  It should fill in the new
     	 creds or return an error.  All pointers, barring the pointer to the
     	 new creds, are now const.

     (*) security_bprm_apply_creds(), ->bprm_apply_creds()

     	 Changed; now returns a value, which will cause the process to be
     	 killed if it's an error.

     (*) security_task_alloc(), ->task_alloc_security()

     	 Removed in favour of security_prepare_creds().

     (*) security_cred_free(), ->cred_free()

     	 New.  Free security data attached to cred->security.

     (*) security_prepare_creds(), ->cred_prepare()

     	 New. Duplicate any security data attached to cred->security.

     (*) security_commit_creds(), ->cred_commit()

     	 New. Apply any security effects for the upcoming installation of new
     	 security by commit_creds().

     (*) security_task_post_setuid(), ->task_post_setuid()

     	 Removed in favour of security_task_fix_setuid().

     (*) security_task_fix_setuid(), ->task_fix_setuid()

     	 Fix up the proposed new credentials for setuid().  This is used by
     	 cap_set_fix_setuid() to implicitly adjust capabilities in line with
     	 setuid() changes.  Changes are made to the new credentials, rather
     	 than the task itself as in security_task_post_setuid().

     (*) security_task_reparent_to_init(), ->task_reparent_to_init()

     	 Removed.  Instead the task being reparented to init is referred
     	 directly to init's credentials.

	 NOTE!  This results in the loss of some state: SELinux's osid no
	 longer records the sid of the thread that forked it.

     (*) security_key_alloc(), ->key_alloc()
     (*) security_key_permission(), ->key_permission()

     	 Changed.  These now take cred pointers rather than task pointers to
     	 refer to the security context.

 (4) sys_capset().

     This has been simplified and uses less locking.  The LSM functions it
     calls have been merged.

 (5) reparent_to_kthreadd().

     This gives the current thread the same credentials as init by simply using
     commit_thread() to point that way.

 (6) __sigqueue_alloc() and switch_uid()

     __sigqueue_alloc() can't stop the target task from changing its creds
     beneath it, so this function gets a reference to the currently applicable
     user_struct which it then passes into the sigqueue struct it returns if
     successful.

     switch_uid() is now called from commit_creds(), and possibly should be
     folded into that.  commit_creds() should take care of protecting
     __sigqueue_alloc().

 (7) [sg]et[ug]id() and co and [sg]et_current_groups.

     The set functions now all use prepare_creds(), commit_creds() and
     abort_creds() to build and check a new set of credentials before applying
     it.

     security_task_set[ug]id() is called inside the prepared section.  This
     guarantees that nothing else will affect the creds until we've finished.

     The calling of set_dumpable() has been moved into commit_creds().

     Much of the functionality of set_user() has been moved into
     commit_creds().

     The get functions all simply access the data directly.

 (8) security_task_prctl() and cap_task_prctl().

     security_task_prctl() has been modified to return -ENOSYS if it doesn't
     want to handle a function, or otherwise return the return value directly
     rather than through an argument.

     Additionally, cap_task_prctl() now prepares a new set of credentials, even
     if it doesn't end up using it.

 (9) Keyrings.

     A number of changes have been made to the keyrings code:

     (a) switch_uid_keyring(), copy_keys(), exit_keys() and suid_keys() have
     	 all been dropped and built in to the credentials functions directly.
     	 They may want separating out again later.

     (b) key_alloc() and search_process_keyrings() now take a cred pointer
     	 rather than a task pointer to specify the security context.

     (c) copy_creds() gives a new thread within the same thread group a new
     	 thread keyring if its parent had one, otherwise it discards the thread
     	 keyring.

     (d) The authorisation key now points directly to the credentials to extend
     	 the search into rather pointing to the task that carries them.

     (e) Installing thread, process or session keyrings causes a new set of
     	 credentials to be created, even though it's not strictly necessary for
     	 process or session keyrings (they're shared).

(10) Usermode helper.

     The usermode helper code now carries a cred struct pointer in its
     subprocess_info struct instead of a new session keyring pointer.  This set
     of credentials is derived from init_cred and installed on the new process
     after it has been cloned.

     call_usermodehelper_setup() allocates the new credentials and
     call_usermodehelper_freeinfo() discards them if they haven't been used.  A
     special cred function (prepare_usermodeinfo_creds()) is provided
     specifically for call_usermodehelper_setup() to call.

     call_usermodehelper_setkeys() adjusts the credentials to sport the
     supplied keyring as the new session keyring.

(11) SELinux.

     SELinux has a number of changes, in addition to those to support the LSM
     interface changes mentioned above:

     (a) selinux_setprocattr() no longer does its check for whether the
     	 current ptracer can access processes with the new SID inside the lock
     	 that covers getting the ptracer's SID.  Whilst this lock ensures that
     	 the check is done with the ptracer pinned, the result is only valid
     	 until the lock is released, so there's no point doing it inside the
     	 lock.

(12) is_single_threaded().

     This function has been extracted from selinux_setprocattr() and put into
     a file of its own in the lib/ directory as join_session_keyring() now
     wants to use it too.

     The code in SELinux just checked to see whether a task shared mm_structs
     with other tasks (CLONE_VM), but that isn't good enough.  We really want
     to know if they're part of the same thread group (CLONE_THREAD).

(13) nfsd.

     The NFS server daemon now has to use the COW credentials to set the
     credentials it is going to use.  It really needs to pass the credentials
     down to the functions it calls, but it can't do that until other patches
     in this series have been applied.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NJames Morris <jmorris@namei.org>
      d84f4f99
    • D
      CRED: Pass credentials through dentry_open() · 745ca247
      由 David Howells 提交于 
      Pass credentials through dentry_open() so that the COW creds patch can have
SELinux's flush_unauthorized_files() pass the appropriate creds back to itself
when it opens its null chardev.

The security_dentry_open() call also now takes a creds pointer, as does the
dentry_open hook in struct security_operations.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NJames Morris <jmorris@namei.org>
      745ca247
    • D
      CRED: Separate task security context from task_struct · b6dff3ec
      由 David Howells 提交于 
      Separate the task security context from task_struct.  At this point, the
security data is temporarily embedded in the task_struct with two pointers
pointing to it.

Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in
entry.S via asm-offsets.

With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NJames Morris <jmorris@namei.org>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>
      b6dff3ec
  15. 23 10月, 2008 1 次提交
  17. 19 4月, 2008 2 次提交
  19. 15 2月, 2008 2 次提交
  21. 02 11月, 2007 1 次提交
  23. 23 10月, 2007 1 次提交
  25. 22 5月, 2007 1 次提交
    • A
      Detach sched.h from mm.h · e8edc6e0
      由 Alexey Dobriyan 提交于 
      First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.

This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
   getting them indirectly

Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
   they don't need sched.h
b) sched.h stops being dependency for significant number of files:
   on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
   after patch it's only 3744 (-8.3%).

Cross-compile tested on

	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
	alpha alpha-up
	arm
	i386 i386-up i386-defconfig i386-allnoconfig
	ia64 ia64-up
	m68k
	mips
	parisc parisc-up
	powerpc powerpc-up
	s390 s390-up
	sparc sparc-up
	sparc64 sparc64-up
	um-x86_64
	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

as well as my two usual configs.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e8edc6e0
  27. 09 12月, 2006 1 次提交
    • P
      [PATCH] lockdep: annotate nfsd4 recover code · 4b75f78e
      由 Peter Zijlstra 提交于 
      > =============================================
> [ INFO: possible recursive locking detected ]
> 2.6.18-1.2724.lockdepPAE #1
> ---------------------------------------------
> nfsd/6884 is trying to acquire lock:
>  (&inode->i_mutex){--..}, at: [<c04811e5>] vfs_rmdir+0x73/0xf4
>
> but task is already holding lock:
>  (&inode->i_mutex){--..}, at: [<f8dfa621>]
> nfsd4_clear_clid_dir+0x1f/0x3d [nfsd]
>
> other info that might help us debug this:
> 3 locks held by nfsd/6884:
>  #0:  (hash_sem){----}, at: [<f8de05eb>] nfsd+0x181/0x2ea [nfsd]
>  #1:  (client_mutex){--..}, at: [<f8df6d19>]
> nfsd4_setclientid_confirm+0x3b/0x2cf [nfsd]
>  #2:  (&inode->i_mutex){--..}, at: [<f8dfa621>]
> nfsd4_clear_clid_dir+0x1f/0x3d [nfsd]
>
> stack backtrace:
>  [<c040524d>] dump_trace+0x69/0x1af
>  [<c04053ab>] show_trace_log_lvl+0x18/0x2c
>  [<c040595f>] show_trace+0xf/0x11
>  [<c0405a53>] dump_stack+0x15/0x17
>  [<c043ca7a>] __lock_acquire+0x110/0x9b6
>  [<c043d91e>] lock_acquire+0x5c/0x7a
>  [<c061a41b>] __mutex_lock_slowpath+0xde/0x234
>  [<c04811e5>] vfs_rmdir+0x73/0xf4
>  [<f8dfa62b>] nfsd4_clear_clid_dir+0x29/0x3d [nfsd]
>  [<f8dfa733>] nfsd4_remove_clid_dir+0xb8/0xf8 [nfsd]
>  [<f8df6e90>] nfsd4_setclientid_confirm+0x1b2/0x2cf [nfsd]
>  [<f8def19a>] nfsd4_proc_compound+0x137a/0x166c [nfsd]
>  [<f8de00d5>] nfsd_dispatch+0xc5/0x180 [nfsd]
>  [<f8d09d83>] svc_process+0x3bd/0x631 [sunrpc]
>  [<f8de0604>] nfsd+0x19a/0x2ea [nfsd]
>  [<c0404e27>] kernel_thread_helper+0x7/0x10
> DWARF2 unwinder stuck at kernel_thread_helper+0x7/0x10
> Leftover inexact backtrace:
>  =======================

Some nesting annotation to the nfsd4 recovery code.
The vfs operations called will take dentry->d_inode->i_mutex.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      4b75f78e
  29. 04 11月, 2006 1 次提交
    • S
      [PATCH] NFS4: fix for recursive locking problem · 7ef55b8a
      由 Srinivasa Ds 提交于 
      When I was performing some operations on NFS, I got below error on server
side.

  =============================================
  [ INFO: possible recursive locking detected ]
  2.6.19-prep #1
  ---------------------------------------------
  nfsd4/3525 is trying to acquire lock:
   (&inode->i_mutex){--..}, at: [<c0611e5a>] mutex_lock+0x21/0x24

  but task is already holding lock:
   (&inode->i_mutex){--..}, at: [<c0611e5a>] mutex_lock+0x21/0x24

  other info that might help us debug this:
  2 locks held by nfsd4/3525:
   #0:  (client_mutex){--..}, at: [<c0611e5a>] mutex_lock+0x21/0x24
   #1:  (&inode->i_mutex){--..}, at: [<c0611e5a>] mutex_lock+0x21/0x24

  stack backtrace:
   [<c04051ed>] show_trace_log_lvl+0x58/0x16a
   [<c04057fa>] show_trace+0xd/0x10
   [<c0405913>] dump_stack+0x19/0x1b
   [<c043b6f1>] __lock_acquire+0x778/0x99c
   [<c043be86>] lock_acquire+0x4b/0x6d
   [<c0611ceb>] __mutex_lock_slowpath+0xbc/0x20a
   [<c0611e5a>] mutex_lock+0x21/0x24
   [<c047fd7e>] vfs_rmdir+0x76/0xf8
   [<f94b7ce9>] nfsd4_clear_clid_dir+0x2c/0x41 [nfsd]
   [<f94b7de9>] nfsd4_remove_clid_dir+0xb1/0xe8 [nfsd]
   [<f94b307b>] laundromat_main+0x9b/0x1c3 [nfsd]
   [<c04333d6>] run_workqueue+0x7a/0xbb
   [<c0433d0b>] worker_thread+0xd2/0x107
   [<c0436285>] kthread+0xc3/0xf2
   [<c0402005>] kernel_thread_helper+0x5/0xb
  ===================================================================

Cause for this problem was,2 successive mutex_lock calls on 2 diffrent inodes ,as shown below

	static int
	nfsd4_clear_clid_dir(struct dentry *dir, struct dentry *dentry)
	{
	        int status;

	        /* For now this directory should already be empty, but we empty it of
        	 * any regular files anyway, just in case the directory was created by
	         * a kernel from the future.... */
        	nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file);
	        mutex_lock(&dir->d_inode->i_mutex);
	        status = vfs_rmdir(dir->d_inode, dentry);
	...

	int vfs_rmdir(struct inode *dir, struct dentry *dentry)
	{
	        int error = may_delete(dir, dentry, 1);

	        if (error)
	                return error;

	        if (!dir->i_op || !dir->i_op->rmdir)
        	        return -EPERM;

	        DQUOT_INIT(dir);

	        mutex_lock(&dentry->d_inode->i_mutex);
	...

So I have developed the patch to overcome this problem.
Signed-off-by: NSrinivasa DS <srinivasa@in.ibm.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      7ef55b8a
  31. 21 10月, 2006 1 次提交
  33. 03 10月, 2006 1 次提交
    • D
      [PATCH] VFS: Make filldir_t and struct kstat deal in 64-bit inode numbers · afefdbb2
      由 David Howells 提交于 
      These patches make the kernel pass 64-bit inode numbers internally when
communicating to userspace, even on a 32-bit system.  They are required
because some filesystems have intrinsic 64-bit inode numbers: NFS3+ and XFS
for example.  The 64-bit inode numbers are then propagated to userspace
automatically where the arch supports it.

Problems have been seen with userspace (eg: ld.so) using the 64-bit inode
number returned by stat64() or getdents64() to differentiate files, and
failing because the 64-bit inode number space was compressed to 32-bits, and
so overlaps occur.

This patch:

Make filldir_t take a 64-bit inode number and struct kstat carry a 64-bit
inode number so that 64-bit inode numbers can be passed back to userspace.

The stat functions then returns the full 64-bit inode number where
available and where possible.  If it is not possible to represent the inode
number supplied by the filesystem in the field provided by userspace, then
error EOVERFLOW will be issued.

Similarly, the getdents/readdir functions now pass the full 64-bit inode
number to userspace where possible, returning EOVERFLOW instead when a
directory entry is encountered that can't be properly represented.

Note that this means that some inodes will not be stat'able on a 32-bit
system with old libraries where they were before - but it does mean that
there will be no ambiguity over what a 32-bit inode number refers to.

Note similarly that directory scans may be cut short with an error on a
32-bit system with old libraries where the scan would work before for the
same reasons.

It is judged unlikely that this situation will occur because modern glibc
uses 64-bit capable versions of stat and getdents class functions
exclusively, and that older systems are unlikely to encounter
unrepresentable inode numbers anyway.

[akpm: alpha build fix]
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      afefdbb2
  35. 21 9月, 2006 1 次提交
  37. 19 1月, 2006 2 次提交
  39. 10 1月, 2006 1 次提交
  41. 02 9月, 2005 2 次提交
  43. 08 7月, 2005 3 次提交
  45. 24 6月, 2005 4 次提交