Use 32-bit or 64-bit llseek() hashes for directory offsets depending on
the NFS version. NFSv2 gets 32-bit hashes only.

NOTE: This patch got rather complex as Christoph asked to set the
filp->f_mode flag in the open call or immediatly after dentry_open()
in nfsd_open() to avoid races.
Personally I still do not see a reason for that and in my opinion
FMODE_32BITHASH/FMODE_64BITHASH flags could be set nfsd_readdir(), as it
follows directly after nfsd_open() without a chance of races.
Signed-off-by: NBernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Acked-by: J. Bruce Fields<bfields@redhat.com>

Just rename this variable, as the next patch will add a flag and
'access' as variable name would not be correct any more.
Signed-off-by: NBernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Acked-by: J. Bruce Fields<bfields@redhat.com>

Traditionally ext2/3/4 has returned a 32-bit hash value from llseek()
to appease NFSv2, which can only handle a 32-bit cookie for seekdir()
and telldir().  However, this causes problems if there are 32-bit hash
collisions, since the NFSv2 server can get stuck resending the same
entries from the directory repeatedly.

Allow ext4 to return a full 64-bit hash (both major and minor) for
telldir to decrease the chance of hash collisions.  This still needs
integration on the NFS side.
Patch-updated-by: NBernd Schubert <bernd.schubert@itwm.fraunhofer.de>
(blame me if something is not correct)
Signed-off-by: NFan Yong <yong.fan@whamcloud.com>
Signed-off-by: NAndreas Dilger <adilger@whamcloud.com>
Signed-off-by: NBernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Not all mtd drivers define block_isbad().  Let's assume no bad blocks
instead of refusing to mount.
Signed-off-by: NJoern Engel <joern@logfs.org>

Can be necessary if an inode gets deleted (through -ENOSPC) before being
written.  Might be better to move this into logfs_write_rec(), but for
now go with the stupid&safe patch.
Signed-off-by: NJoern Engel <joern@logfs.org>

Or hit an assertion in map_invalidatepage() instead.
Signed-off-by: NJoern Engel <joern@logfs.org>

It prevents write sizes >4k.
Signed-off-by: NJoern Engel <joern@logfs.org>

During GC LogFS has to rewrite each valid block to a separate segment.
Rewrite operation reads data from an old segment and writes it to a
newly allocated segment. Since every write operation changes data
block pointers maintained in inode, inode should also be rewritten.

In GC path to avoid AB-BA deadlock LogFS marks a page with
PG_pre_locked in addition to locking the page (PG_locked). The page
lock is ignored iff the page is pre-locked.

LogFS uses a special file called segment file. The segment file
maintains an 8 bytes entry for every segment. It keeps track of erase
count, level etc. for every segment.

Bad things happen with a segment belonging to the segment file is GCed

 ------------[ cut here ]------------
kernel BUG at /home/prasad/logfs/readwrite.c:297!
invalid opcode: 0000 [#1] SMP
Modules linked in: logfs joydev usbhid hid psmouse e1000 i2c_piix4
		serio_raw [last unloaded: logfs]
Pid: 20161, comm: mount Not tainted 3.1.0-rc3+ #3 innotek GmbH
		VirtualBox
EIP: 0060:[<f809132a>] EFLAGS: 00010292 CPU: 0
EIP is at logfs_lock_write_page+0x6a/0x70 [logfs]
EAX: 00000027 EBX: f73f5b20 ECX: c16007c8 EDX: 00000094
ESI: 00000000 EDI: e59be6e4 EBP: c7337b28 ESP: c7337b18
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process mount (pid: 20161, ti=c7336000 task=eb323f70 task.ti=c7336000)
Stack:
f8099a3d c7337b24 f73f5b20 00001002 c7337b50 f8091f6d f8099a4d f80994e4
00000003 00000000 c7337b68 00000000 c67e4400 00001000 c7337b80 f80935e5
00000000 00000000 00000000 00000000 e1fcf000 0000000f e59be618 c70bf900
Call Trace:
[<f8091f6d>] logfs_get_write_page.clone.16+0xdd/0x100 [logfs]
[<f80935e5>] logfs_mod_segment_entry+0x55/0x110 [logfs]
[<f809460d>] logfs_get_segment_entry+0x1d/0x20 [logfs]
[<f8091060>] ? logfs_cleanup_journal+0x50/0x50 [logfs]
[<f809521b>] ostore_get_erase_count+0x1b/0x40 [logfs]
[<f80965b8>] logfs_open_area+0xc8/0x150 [logfs]
[<c141a7ec>] ? kmemleak_alloc+0x2c/0x60
[<f809668e>] __logfs_segment_write.clone.16+0x4e/0x1b0 [logfs]
[<c10dd563>] ? mempool_kmalloc+0x13/0x20
[<c10dd563>] ? mempool_kmalloc+0x13/0x20
[<f809696f>] logfs_segment_write+0x17f/0x1d0 [logfs]
[<f8092e8c>] logfs_write_i0+0x11c/0x180 [logfs]
[<f8092f35>] logfs_write_direct+0x45/0x90 [logfs]
[<f80934cd>] __logfs_write_buf+0xbd/0xf0 [logfs]
[<c102900e>] ? kmap_atomic_prot+0x4e/0xe0
[<f809424b>] logfs_write_buf+0x3b/0x60 [logfs]
[<f80947a9>] __logfs_write_inode+0xa9/0x110 [logfs]
[<f8094cb0>] logfs_rewrite_block+0xc0/0x110 [logfs]
[<f8095300>] ? get_mapping_page+0x10/0x60 [logfs]
[<f8095aa0>] ? logfs_load_object_aliases+0x2e0/0x2f0 [logfs]
[<f808e57d>] logfs_gc_segment+0x2ad/0x310 [logfs]
[<f808e62a>] __logfs_gc_once+0x4a/0x80 [logfs]
[<f808ed43>] logfs_gc_pass+0x683/0x6a0 [logfs]
[<f8097a89>] logfs_mount+0x5a9/0x680 [logfs]
[<c1126b21>] mount_fs+0x21/0xd0
[<c10f6f6f>] ? __alloc_percpu+0xf/0x20
[<c113da41>] ? alloc_vfsmnt+0xb1/0x130
[<c113db4b>] vfs_kern_mount+0x4b/0xa0
[<c113e06e>] do_kern_mount+0x3e/0xe0
[<c113f60d>] do_mount+0x34d/0x670
[<c10f2749>] ? strndup_user+0x49/0x70
[<c113fcab>] sys_mount+0x6b/0xa0
[<c142d87c>] syscall_call+0x7/0xb
Code: f8 e8 8b 93 39 c9 8b 45 f8 3e 0f ba 28 00 19 d2 85 d2 74 ca eb d0 0f 0b 8d 45 fc 89 44 24 04 c7 04 24 3d 9a 09 f8 e8 09 92 39 c9 <0f> 0b 8d 74 26 00 55 89 e5 3e 8d 74 26 00 8b 10 80 e6 01 74 09
EIP: [<f809132a>] logfs_lock_write_page+0x6a/0x70 [logfs] SS:ESP 0068:c7337b18
---[ end trace 96e67d5b3aa3d6ca ]---

The patch passes locked page to __logfs_write_inode. It calls function
logfs_get_wblocks() to pre-lock the page. This ensures any further
attempts to lock the page are ignored (esp from get_erase_count).
Acked-by: NJoern Engel <joern@logfs.org>
Signed-off-by: NPrasad Joshi <prasadjoshi.linux@gmail.com>

While unmounting the file system LogFS calls generic_shutdown_super.
The function does file system independent superblock shutdown.
However, it might result in call file system specific inode eviction.

LogFS marks FS shutting down by setting bit LOGFS_SB_FLAG_SHUTDOWN in
super->s_flags. Since, inode eviction might call truncate on inode,
following BUG is observed when file system is unmounted:

------------[ cut here ]------------
kernel BUG at /home/prasad/logfs/segment.c:362!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU 3
Modules linked in: logfs binfmt_misc ppdev virtio_blk parport_pc lp
	parport psmouse floppy virtio_pci serio_raw virtio_ring virtio

Pid: 1933, comm: umount Not tainted 3.0.0+ #4 Bochs Bochs
RIP: 0010:[<ffffffffa008c841>]  [<ffffffffa008c841>]
		logfs_segment_write+0x211/0x230 [logfs]
RSP: 0018:ffff880062d7b9e8  EFLAGS: 00010202
RAX: 000000000000000e RBX: ffff88006eca9000 RCX: 0000000000000000
RDX: ffff88006fd87c40 RSI: ffffea00014ff468 RDI: ffff88007b68e000
RBP: ffff880062d7ba48 R08: 8000000020451430 R09: 0000000000000000
R10: dead000000100100 R11: 0000000000000000 R12: ffff88006fd87c40
R13: ffffea00014ff468 R14: ffff88005ad0a460 R15: 0000000000000000
FS:  00007f25d50ea760(0000) GS:ffff88007fd80000(0000)
	knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000d05e48 CR3: 0000000062c72000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process umount (pid: 1933, threadinfo ffff880062d7a000,
	task ffff880070b44500)
Stack:
ffff880062d7ba38 ffff88005ad0a508 0000000000001000 0000000000000000
8000000020451430 ffffea00014ff468 ffff880062d7ba48 ffff88005ad0a460
ffff880062d7bad8 ffffea00014ff468 ffff88006fd87c40 0000000000000000
Call Trace:
[<ffffffffa0088fee>] logfs_write_i0+0x12e/0x190 [logfs]
[<ffffffffa0089360>] __logfs_write_rec+0x140/0x220 [logfs]
[<ffffffffa0089312>] __logfs_write_rec+0xf2/0x220 [logfs]
[<ffffffffa00894a4>] logfs_write_rec+0x64/0xd0 [logfs]
[<ffffffffa0089616>] __logfs_write_buf+0x106/0x110 [logfs]
[<ffffffffa008a19e>] logfs_write_buf+0x4e/0x80 [logfs]
[<ffffffffa008a6b8>] __logfs_write_inode+0x98/0x110 [logfs]
[<ffffffffa008a7c4>] logfs_truncate+0x54/0x290 [logfs]
[<ffffffffa008abfc>] logfs_evict_inode+0xdc/0x190 [logfs]
[<ffffffff8115eef5>] evict+0x85/0x170
[<ffffffff8115f126>] iput+0xe6/0x1b0
[<ffffffff8115b4a8>] shrink_dcache_for_umount_subtree+0x218/0x280
[<ffffffff8115ce91>] shrink_dcache_for_umount+0x51/0x90
[<ffffffff8114796c>] generic_shutdown_super+0x2c/0x100
[<ffffffffa008cc47>] logfs_kill_sb+0x57/0xf0 [logfs]
[<ffffffff81147de5>] deactivate_locked_super+0x45/0x70
[<ffffffff811487ea>] deactivate_super+0x4a/0x70
[<ffffffff81163934>] mntput_no_expire+0xa4/0xf0
[<ffffffff8116469f>] sys_umount+0x6f/0x380
[<ffffffff814dd46b>] system_call_fastpath+0x16/0x1b
Code: 55 c8 49 8d b6 a8 00 00 00 45 89 f9 45 89 e8 4c 89 e1 4c 89 55
b8 c7 04 24 00 00 00 00 e8 68 fc ff ff 4c 8b 55 b8 e9 3c ff ff ff <0f>
0b 0f 0b c7 45 c0 00 00 00 00 e9 44 fe ff ff 66 66 66 66 66
RIP  [<ffffffffa008c841>] logfs_segment_write+0x211/0x230 [logfs]
RSP <ffff880062d7b9e8>
---[ end trace fe6b040cea952290 ]---

Therefore, move super->s_flags setting after the fs-indenpendent work
has been finished.
Reviewed-by: NJoern Engel <joern@logfs.org>
Signed-off-by: NPrasad Joshi <prasadjoshi.linux@gmail.com>

LogFS uses super->s_write_mutex while writing data to disk. Taking the
same mutex lock in sync and fsync code path solves the following BUG:

------------[ cut here ]------------
kernel BUG at /home/prasad/logfs/dev_bdev.c:134!

Pid: 2387, comm: flush-253:16 Not tainted 3.0.0+ #4 Bochs Bochs
RIP: 0010:[<ffffffffa007deed>]  [<ffffffffa007deed>]
                bdev_writeseg+0x25d/0x270 [logfs]
Call Trace:
[<ffffffffa007c381>] logfs_open_area+0x91/0x150 [logfs]
[<ffffffff8128dcb2>] ? find_level.clone.9+0x62/0x100
[<ffffffffa007c49c>] __logfs_segment_write.clone.20+0x5c/0x190 [logfs]
[<ffffffff810ef005>] ? mempool_kmalloc+0x15/0x20
[<ffffffff810ef383>] ? mempool_alloc+0x53/0x130
[<ffffffffa007c7a4>] logfs_segment_write+0x1d4/0x230 [logfs]
[<ffffffffa0078f8e>] logfs_write_i0+0x12e/0x190 [logfs]
[<ffffffffa0079300>] __logfs_write_rec+0x140/0x220 [logfs]
[<ffffffffa0079444>] logfs_write_rec+0x64/0xd0 [logfs]
[<ffffffffa00795b6>] __logfs_write_buf+0x106/0x110 [logfs]
[<ffffffffa007a13e>] logfs_write_buf+0x4e/0x80 [logfs]
[<ffffffffa0073e33>] __logfs_writepage+0x23/0x80 [logfs]
[<ffffffffa007410c>] logfs_writepage+0xdc/0x110 [logfs]
[<ffffffff810f5ba7>] __writepage+0x17/0x40
[<ffffffff810f6208>] write_cache_pages+0x208/0x4f0
[<ffffffff810f5b90>] ? set_page_dirty+0x70/0x70
[<ffffffff810f653a>] generic_writepages+0x4a/0x70
[<ffffffff810f75d1>] do_writepages+0x21/0x40
[<ffffffff8116b9d1>] writeback_single_inode+0x101/0x250
[<ffffffff8116bdbd>] writeback_sb_inodes+0xed/0x1c0
[<ffffffff8116c5fb>] writeback_inodes_wb+0x7b/0x1e0
[<ffffffff8116cc23>] wb_writeback+0x4c3/0x530
[<ffffffff814d984d>] ? sub_preempt_count+0x9d/0xd0
[<ffffffff8116cd6b>] wb_do_writeback+0xdb/0x290
[<ffffffff814d984d>] ? sub_preempt_count+0x9d/0xd0
[<ffffffff814d6208>] ? _raw_spin_unlock_irqrestore+0x18/0x40
[<ffffffff8105aa5a>] ? del_timer+0x8a/0x120
[<ffffffff8116cfac>] bdi_writeback_thread+0x8c/0x2e0
[<ffffffff8116cf20>] ? wb_do_writeback+0x290/0x290
[<ffffffff8106d2e6>] kthread+0x96/0xa0
[<ffffffff814de514>] kernel_thread_helper+0x4/0x10
[<ffffffff8106d250>] ? kthread_worker_fn+0x190/0x190
[<ffffffff814de510>] ? gs_change+0xb/0xb
RIP  [<ffffffffa007deed>] bdev_writeseg+0x25d/0x270 [logfs]
---[ end trace 0211ad60a57657c4 ]---
Reviewed-by: NJoern Engel <joern@logfs.org>
Signed-off-by: NPrasad Joshi <prasadjoshi.linux@gmail.com>

This is a bad one.  I wonder whether we were so far protected by
no_free_segments(sb) usually being smaller than LOGFS_NO_AREAS.

Found by Dan Carpenter <dan.carpenter@oracle.com> using smatch.
Signed-off-by: NJoern Engel <joern@logfs.org>
Signed-off-by: NPrasad Joshi <prasadjoshi.linux@gmail.com>

LogFS sets PG_private flag to indicate a pined page. We assumed that
marking a page as private is enough to ensure its existence. But
instead it is necessary to hold a reference count to the page.

The change resolves the following BUG

BUG: Bad page state in process flush-253:16  pfn:6a6d0
page flags: 0x100000000000808(uptodate|private)
Suggested-and-Acked-by: NJoern Engel <joern@logfs.org>
Signed-off-by: NPrasad Joshi <prasadjoshi.linux@gmail.com>

Josef fixed btrfs_page_mkwrite to properly release reserved
extents if there was an error.  But if we fail to get a reservation
and we fail to dirty the inode (for ENOSPC reasons), we'll end up
trying to release a reservation we never had.

This makes sure we only release if we were able to reserve.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

If we span a long area in a bitmap we could end up taking a lot of time
searching to the next free area if we're searching from the original
window_start, so advance window_start in order to make sure we don't do any
superficial searching.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

btree_releasepage is a callback and can be passed unknown gfp flags and then
they may end up in kmem_cache_alloc called from alloc_extent_state, slab
allocator will BUG_ON when there is HIGHMEM or DMA32 flag set.

This may happen when btrfs is mounted from a loop device, which masks out
__GFP_IO flag. The check in try_release_extent_state

3399                 if ((mask & GFP_NOFS) == GFP_NOFS)
3400                         mask = GFP_NOFS;

will not work and passes unfiltered flags further resulting in crash at
mm/slab.c:2963

 [<000000000024ae4c>] cache_alloc_refill+0x3b4/0x5c8
 [<000000000024c810>] kmem_cache_alloc+0x204/0x294
 [<00000000001fd3c2>] mempool_alloc+0x52/0x170
 [<000003c000ced0b0>] alloc_extent_state+0x40/0xd4 [btrfs]
 [<000003c000cee5ae>] __clear_extent_bit+0x38a/0x4cc [btrfs]
 [<000003c000cee78c>] try_release_extent_state+0x9c/0xd4 [btrfs]
 [<000003c000cc4c66>] btree_releasepage+0x7e/0xd0 [btrfs]
 [<0000000000210d84>] shrink_page_list+0x6a0/0x724
 [<0000000000211394>] shrink_inactive_list+0x230/0x578
 [<0000000000211bb8>] shrink_list+0x6c/0x120
 [<0000000000211e4e>] shrink_zone+0x1e2/0x228
 [<0000000000211f24>] shrink_zones+0x90/0x254
 [<0000000000213410>] do_try_to_free_pages+0xac/0x420
 [<0000000000213ae0>] try_to_free_pages+0x13c/0x1b0
 [<0000000000204e6c>] __alloc_pages_nodemask+0x5b4/0x9a8
 [<00000000001fb04a>] grab_cache_page_write_begin+0x7e/0xe8
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When we did sysbench test for inline files, enospc error happened easily though
there was lots of free disk space which could be allocated for new chunks.

Reproduce steps:
 # mkfs.btrfs -b $((2 * 1024 * 1024 * 1024)) <test partition>
 # mount <test partition> /mnt
 # ulimit -n 102400
 # cd /mnt
 # sysbench --num-threads=1 --test=fileio --file-num=81920 \
 > --file-total-size=80M --file-block-size=1K --file-io-mode=sync \
 > --file-test-mode=seqwr prepare
 # sysbench --num-threads=1 --test=fileio --file-num=81920 \
 > --file-total-size=80M --file-block-size=1K --file-io-mode=sync \
 > --file-test-mode=seqwr run
 <soon later, BUG_ON() was triggered by enospc error>

The reason of this bug is:
Now, we can reserve space which is larger than the free space in the chunks if
we have enough free disk space which can be used for new chunks. By this way,
the space allocator should allocate a new chunk by force if there is no free
space in the free space cache. But there are two wrong checks which break this
operation.

One is
	if (ret == -ENOSPC && num_bytes > min_alloc_size)
in btrfs_reserve_extent(), it is wrong, we should try to allocate a new chunk
even we fail to allocate free space by minimum allocable size.

The other is
	if (space_info->force_alloc)
		force = space_info->force_alloc;
in do_chunk_alloc(). It makes the allocator ignore CHUNK_ALLOC_FORCE If someone
sets ->force_alloc to CHUNK_ALLOC_LIMITED, and makes the enospc error happen.

Fix these two wrong checks. Especially the second one, we fix it by changing
the value of CHUNK_ALLOC_LIMITED and CHUNK_ALLOC_FORCE, and make
CHUNK_ALLOC_FORCE greater than CHUNK_ALLOC_LIMITED since CHUNK_ALLOC_FORCE has
higher priority. And if the value which is passed in by the caller is greater
than ->force_alloc, use the passed value.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

xfstests 218 complains that btrfs defrags a file partially:
 After: 1
 Write backwards sync, but contiguous - should defrag to 1 extent
 Before: 10
-After: 1
+After: 2

To fix this, we need to set max_to_defrag count properly.
Signed-off-by: NLiu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

There have been 4 warnings on 32-bit build, they are herewith fixed.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We specifically set window_start in the cluster struct to indicate where the
cluster starts in a bitmap, but we've been using min_start to indicate where
we're searching from.  This is usually the start of the blockgroup, so
essentially means we're constantly searching from the start of any bitmap we
find, which completely negates all the trouble we go to in order to setup a
cluster.  So start using window_start to make sure we actually use the area we
found.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

A user has encountered a NULL pointer kernel oops in btrfs when
encountering media errors.  The problem has been identified
as an unhandled NULL pointer returned from find_get_page().
This modification simply checks for a NULL page, and returns
with an error if found (the extent_range_uptodate() function
returns 1 on errors).

After testing this patch, the user reported that the error with
the NULL pointer oops was solved.  However, there is still a
remaining problem with a thread becoming stuck in
wait_on_page_locked(page) in the read_extent_buffer_pages(...)
function in extent_io.c

       for (i = start_i; i < num_pages; i++) {
               page = extent_buffer_page(eb, i);
               wait_on_page_locked(page);
               if (!PageUptodate(page))
                       ret = -EIO;
       }

This patch leaves the issue with the locked page yet to be resolved.
Signed-off-by: NMitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

wait_log_commit() and wait_for_writer() were using slightly different
conditions for deciding whether they should call schedule() and whether they
should continue in the wait loop. Thus it could happen that we busylooped when
the first condition was not true while the second one was. That is burning CPU
cycles needlessly and is deadly on UP machines...
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We have only been checking for min_bytes available in bitmap entries, but we
won't successfully setup a bitmap cluster unless it has at least bytes in the
bitmap, so in the common case min_bytes is 4k and we want something like 2MB, so
if there are a bunch of bitmap entries with less than 2mb's in them, we'll
search all them anyway, which is suboptimal.  Fix this check.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Added initialization with the declaration of ret. It isn't set later on the
switch-default branch (which should never be taken).
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

 The data encryption was moved from ecryptfs_write_end into
ecryptfs_writepage, this patch moves the corresponding function
comments to be consistent with the modification.
Signed-off-by: NLi Wang <liwang@nudt.edu.cn>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If pages passed to the eCryptfs extent-based crypto functions are not
mapped and the module parameter ecryptfs_verbosity=1 was specified at
loading time, a NULL pointer dereference will occur.

Note that this wouldn't happen on a production system, as you wouldn't
pass ecryptfs_verbosity=1 on a production system. It leaks private
information to the system logs and is for debugging only.

The debugging info printed in these messages is no longer very useful
and rather than doing a kmap() in these debugging paths, it will be
better to simply remove the debugging paths completely.

https://launchpad.net/bugs/913651Signed-off-by: NTyler Hicks <tyhicks@canonical.com>
Reported-by: Daniel DeFreez
Cc: <stable@vger.kernel.org>

ecryptfs_read() has been ifdef'ed out for years now and it was
apparently unused before then. It is time to get rid of it for good.
Signed-off-by: NTyler Hicks <tyhicks@canonical.com>

Most filesystems call inode_change_ok() very early in ->setattr(), but
eCryptfs didn't call it at all. It allowed the lower filesystem to make
the call in its ->setattr() function. Then, eCryptfs would copy the
appropriate inode attributes from the lower inode to the eCryptfs inode.

This patch changes that and actually calls inode_change_ok() on the
eCryptfs inode, fairly early in ecryptfs_setattr(). Ideally, the call
would happen earlier in ecryptfs_setattr(), but there are some possible
inode initialization steps that must happen first.

Since the call was already being made on the lower inode, the change in
functionality should be minimal, except for the case of a file extending
truncate call. In that case, inode_newsize_ok() was never being
called on the eCryptfs inode. Rather than inode_newsize_ok() catching
maximum file size errors early on, eCryptfs would encrypt zeroed pages
and write them to the lower filesystem until the lower filesystem's
write path caught the error in generic_write_checks(). This patch
introduces a new function, called ecryptfs_inode_newsize_ok(), which
checks if the new lower file size is within the appropriate limits when
the truncate operation will be growing the lower file.

In summary this change prevents eCryptfs truncate operations (and the
resulting page encryptions), which would exceed the lower filesystem
limits or FSIZE rlimits, from ever starting.
Signed-off-by: NTyler Hicks <tyhicks@canonical.com>
Reviewed-by: NLi Wang <liwang@nudt.edu.cn>
Cc: <stable@vger.kernel.org>

ecryptfs_write() handles the truncation of eCryptfs inodes. It grabs a
page, zeroes out the appropriate portions, and then encrypts the page
before writing it to the lower filesystem. It was unkillable and due to
the lack of sparse file support could result in tying up a large portion
of system resources, while encrypting pages of zeros, with no way for
the truncate operation to be stopped from userspace.

This patch adds the ability for ecryptfs_write() to detect a pending
fatal signal and return as gracefully as possible. The intent is to
leave the lower file in a useable state, while still allowing a user to
break out of the encryption loop. If a pending fatal signal is detected,
the eCryptfs inode size is updated to reflect the modified inode size
and then -EINTR is returned.
Signed-off-by: NTyler Hicks <tyhicks@canonical.com>
Cc: <stable@vger.kernel.org>

ecryptfs_write() can enter an infinite loop when truncating a file to a
size larger than 4G. This only happens on architectures where size_t is
represented by 32 bits.

This was caused by a size_t overflow due to it incorrectly being used to
store the result of a calculation which uses potentially large values of
type loff_t.

[tyhicks@canonical.com: rewrite subject and commit message]
Signed-off-by: NLi Wang <liwang@nudt.edu.cn>
Signed-off-by: NYunchuan Wen <wenyunchuan@kylinos.com.cn>
Reviewed-by: NCong Wang <xiyou.wangcong@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTyler Hicks <tyhicks@canonical.com>

ecryptfs_miscdev_read() and ecryptfs_miscdev_write() contained many
magic numbers for specifying packet header field sizes and offsets. This
patch defines those values and replaces the magic values.
Signed-off-by: NTyler Hicks <tyhicks@canonical.com>

Errors in writes to /dev/ecryptfs were being incorrectly reported by
returning 0 or the value of the original write count.

This patch clears up the return code assignment in error paths.
Signed-off-by: NTyler Hicks <tyhicks@canonical.com>

A malicious count value specified when writing to /dev/ecryptfs may
result in a a very large kernel memory allocation.

This patch peeks at the specified packet payload size, adds that to the
size of the packet headers and compares the result with the write count
value. The resulting maximum memory allocation size is approximately 532
bytes.
Signed-off-by: NTyler Hicks <tyhicks@canonical.com>
Reported-by: NSasha Levin <levinsasha928@gmail.com>
Cc: <stable@vger.kernel.org>

Removes unneeded variable initialization in ecryptfs_read_metadata(). Also adds
a small comment to help explain metadata reading logic.

[tyhicks@canonical.com: Pulled out of for-stable patch and wrote commit msg]
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Signed-off-by: NTyler Hicks <tyhicks@canonical.com>

Print inode on metadata read failure. The only real
way of dealing with metadata read failures is to delete
the underlying file system file. Having the inode
allows one to 'find . -inum INODE`.

[tyhicks@canonical.com: Removed some minor not-for-stable parts]
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: NTyler Hicks <tyhicks@canonical.com>

Commit b52a360b forgot to call xfs_iunlock() when it detected corrupted
symplink and bailed out. Fix it by jumping to 'out' instead of doing return.

CC: stable@kernel.org
CC: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Reviewed-by: NAlex Elder <elder@kernel.org>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com> 

Recently an OOPS was observed from the usb serial io_ti driver when it tried to remove
sysfs directories.  Upon investigation it turns out this driver was always buggy
and that a recent sysfs change had stopped guarding itself against removing attributes
from sysfs directories that had already been removed. :(

Historically we have been silent about attempting to files from nonexistent sysfs
directories and have politely returned error codes.  That has resulted in people writing
broken code that ignores the error codes.

Issue a kernel WARNING and a stack backtrace to make it clear in no uncertain
terms that abusing sysfs is not ok, and the callers need to fix their code.

This change transforms the io_ti OOPS into a more comprehensible error message
and stack backtrace.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Reported-by: NWolfgang Frisch <wfpub@roembden.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fix new kernel-doc warnings:

Warning(fs/debugfs/file.c:556): No description found for parameter 'nregs'
Warning(fs/debugfs/file.c:556): Excess function parameter 'mregs' description in 'debugfs_print_regs32'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fix new kernel-doc warnings:

Warning(fs/debugfs/file.c:556): No description found for parameter 'nregs'
Warning(fs/debugfs/file.c:556): Excess function parameter 'mregs' description in 'debugfs_print_regs32'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

/proc/pid/clear_refs is used to clear the Referenced and YOUNG bits for
pages and corresponding page table entries of the task with PID pid, which
includes any special mappings inserted into the page tables in order to
provide things like vDSOs and user helper functions.

On ARM this causes a problem because the vectors page is mapped as a
global mapping and since ec706dab ("ARM: add a vma entry for the user
accessible vector page"), a VMA is also inserted into each task for this
page to aid unwinding through signals and syscall restarts.  Since the
vectors page is required for handling faults, clearing the YOUNG bit (and
subsequently writing a faulting pte) means that we lose the vectors page
*globally* and cannot fault it back in.  This results in a system deadlock
on the next exception.

To see this problem in action, just run:

	$ echo 1 > /proc/self/clear_refs

on an ARM platform (as any user) and watch your system hang.  I think this
has been the case since 2.6.37

This patch avoids clearing the aforementioned bits for reserved pages,
therefore leaving the vectors page intact on ARM.  Since reserved pages
are not candidates for swap, this change should not have any impact on the
usefulness of clear_refs.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Reported-by: NMoussa Ba <moussaba@micron.com>
Acked-by: NHugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Acked-by: NNicolas Pitre <nico@linaro.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: <stable@vger.kernel.org>		[2.6.37+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>