linux-toradex.git/drivers/mtd/ubi, branch v4.9.83

ubi: block: Fix locking for idr_alloc/idr_remove

2018-02-17T12:21:14+00:00

commit 7f29ae9f977bcdc3654e68bc36d170223c52fd48 upstream.

This fixes a race with idr_alloc where gd->first_minor can be set to the
same value for two simultaneous calls to ubiblock_create.  Each instance
calls device_add_disk with the same first_minor.  device_add_disk calls
bdi_register_owner which generates several warnings.

WARNING: CPU: 1 PID: 179 at kernel-source/fs/sysfs/dir.c:31
sysfs_warn_dup+0x68/0x88
sysfs: cannot create duplicate filename '/devices/virtual/bdi/252:2'

WARNING: CPU: 1 PID: 179 at kernel-source/lib/kobject.c:240
kobject_add_internal+0x1ec/0x2f8
kobject_add_internal failed for 252:2 with -EEXIST, don't try to
register things with the same name in the same directory

WARNING: CPU: 1 PID: 179 at kernel-source/fs/sysfs/dir.c:31
sysfs_warn_dup+0x68/0x88
sysfs: cannot create duplicate filename '/dev/block/252:2'

However, device_add_disk does not error out when bdi_register_owner
returns an error.  Control continues until reaching blk_register_queue.
It then BUGs.

kernel BUG at kernel-source/fs/sysfs/group.c:113!
[] (internal_create_group) from []
(sysfs_create_group+0x20/0x24)
[] (sysfs_create_group) from []
(blk_trace_init_sysfs+0x18/0x20)
[] (blk_trace_init_sysfs) from []
(blk_register_queue+0xd8/0x154)
[] (blk_register_queue) from []
(device_add_disk+0x194/0x44c)
[] (device_add_disk) from []
(ubiblock_create+0x284/0x2e0)
[] (ubiblock_create) from []
(vol_cdev_ioctl+0x450/0x554)
[] (vol_cdev_ioctl) from [] (vfs_ioctl+0x30/0x44)
[] (vfs_ioctl) from [] (do_vfs_ioctl+0xa0/0x790)
[] (do_vfs_ioctl) from [] (SyS_ioctl+0x44/0x68)
[] (SyS_ioctl) from [] (ret_fast_syscall+0x0/0x34)

Locking idr_alloc/idr_remove removes the race and keeps gd->first_minor
unique.

Fixes: 2bf50d42f3a4 ("UBI: block: Dynamically allocate minor numbers")
Signed-off-by: Bradley Bolen 
Reviewed-by: Boris Brezillon 
Signed-off-by: Richard Weinberger 
Signed-off-by: Greg Kroah-Hartman

ubi: fastmap: Erase outdated anchor PEBs during attach

2018-02-17T12:21:14+00:00

commit f78e5623f45bab2b726eec29dc5cefbbab2d0b1c upstream.

The fastmap update code might erase the current fastmap anchor PEB
in case it doesn't find any new free PEB. When a power cut happens
in this situation we must not have any outdated fastmap anchor PEB
on the device, because that would be used to attach during next
boot.
The easiest way to make that sure is to erase all outdated fastmap
anchor PEBs synchronously during attach.

Signed-off-by: Sascha Hauer 
Reviewed-by: Richard Weinberger 
Fixes: dbb7d2a88d2a ("UBI: Add fastmap core")
Signed-off-by: Richard Weinberger 
Signed-off-by: Greg Kroah-Hartman

ubi/upd: Always flush after prepared for an update

2017-04-27T07:10:38+00:00

commit 9cd9a21ce070be8a918ffd3381468315a7a76ba6 upstream.

In commit 6afaf8a484cb ("UBI: flush wl before clearing update marker") I
managed to trigger and fix a similar bug. Now here is another version of
which I assumed it wouldn't matter back then but it turns out UBI has a
check for it and will error out like this:

|ubi0 warning: validate_vid_hdr: inconsistent used_ebs
|ubi0 error: validate_vid_hdr: inconsistent VID header at PEB 592

All you need to trigger this is? "ubiupdatevol /dev/ubi0_0 file" + a
powercut in the middle of the operation.
ubi_start_update() sets the update-marker and puts all EBs on the erase
list. After that userland can proceed to write new data while the old EB
aren't erased completely. A powercut at this point is usually not that
much of a tragedy. UBI won't give read access to the static volume
because it has the update marker. It will most likely set the corrupted
flag because it misses some EBs.
So we are all good. Unless the size of the image that has been written
differs from the old image in the magnitude of at least one EB. In that
case UBI will find two different values for `used_ebs' and refuse to
attach the image with the error message mentioned above.

So in order not to get in the situation, the patch will ensure that we
wait until everything is removed before it tries to write any data.
The alternative would be to detect such a case and remove all EBs at the
attached time after we processed the volume-table and see the
update-marker set. The patch looks bigger and I doubt it is worth it
since usually the write() will wait from time to time for a new EB since
usually there not that many spare EB that can be used.

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Richard Weinberger 
Signed-off-by: Greg Kroah-Hartman

ubi: fastmap: Fix add_vol() return value test in ubi_attach_fastmap()

2016-10-28T12:48:18+00:00

Commit e96a8a3bb671 ("UBI: Fastmap: Do not add vol if it already
exists") introduced a bug by changing the possible error codes returned
by add_vol():
- this function no longer returns NULL in case of allocation failure
  but return ERR_PTR(-ENOMEM)
- when a duplicate entry in the volume RB tree is found it returns
  ERR_PTR(-EEXIST) instead of ERR_PTR(-EINVAL)

Fix the tests done on add_vol() return val to match this new behavior.

Fixes: e96a8a3bb671 ("UBI: Fastmap: Do not add vol if it already exists")
Reported-by: Dan Carpenter 
Signed-off-by: Boris Brezillon 
Acked-by: Sheng Yong 
Signed-off-by: Richard Weinberger

UBI: Fix crash in try_recover_peb()

2016-10-19T22:06:06+00:00

    drivers/mtd/ubi/eba.c: In function ‘try_recover_peb’:
    drivers/mtd/ubi/eba.c:744: warning: ‘vid_hdr’ is used uninitialized in this function

The pointer vid_hdr is indeed not initialized, leading to a crash when
it is dereferenced.

Fix this by obtaining the pointer from the VID buffer, like is done
everywhere else.

Fixes: 3291b52f9ff0acc8 ("UBI: introduce the VID buffer concept")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Boris Brezillon 
Signed-off-by: Richard Weinberger

ubi: fix swapped arguments to call to ubi_alloc_aeb

2016-10-19T22:06:00+00:00

Static analysis by CoverityScan detected the ec and pnum
arguments are in the wrong order on a call to ubi_alloc_aeb.
Swap the order to fix this.

Fixes: 91f4285fe389a27 ("UBI: provide helpers to allocate and free aeb elements")
Signed-off-by: Colin Ian King 
Reviewed-by: Boris Brezillon 
Signed-off-by: Richard Weinberger

Merge tag 'upstream-4.9-rc1' of git://git.infradead.org/linux-ubifs

2016-10-11T17:49:44+00:00

Pull UBI/UBIFS updates from Richard Weinberger:
 "This pull request contains:

   - Fixes for both UBI and UBIFS
   - overlayfs support (O_TMPFILE, RENAME_WHITEOUT/EXCHANGE)
   - Code refactoring for the upcoming MLC support"

[ Ugh, we just got rid of the "rename2()" naming for the extended rename
  functionality. And this re-introduces it in ubifs with the cross-
  renaming and whiteout support.

  But rather than do any re-organizations in the merge itself, the
  naming can be cleaned up later ]

* tag 'upstream-4.9-rc1' of git://git.infradead.org/linux-ubifs: (27 commits)
  UBIFS: improve function-level documentation
  ubifs: fix host xattr_len when changing xattr
  ubifs: Use move variable in ubifs_rename()
  ubifs: Implement RENAME_EXCHANGE
  ubifs: Implement RENAME_WHITEOUT
  ubifs: Implement O_TMPFILE
  ubi: Fix Fastmap's update_vol()
  ubi: Fix races around ubi_refill_pools()
  ubi: Deal with interrupted erasures in WL
  UBI: introduce the VID buffer concept
  UBI: hide EBA internals
  UBI: provide an helper to query LEB information
  UBI: provide an helper to check whether a LEB is mapped or not
  UBI: add an helper to check lnum validity
  UBI: simplify LEB write and atomic LEB change code
  UBI: simplify recover_peb() code
  UBI: move the global ech and vidh variables into struct ubi_attach_info
  UBI: provide helpers to allocate and free aeb elements
  UBI: fastmap: use ubi_io_{read, write}_data() instead of ubi_io_{read, write}()
  UBI: fastmap: use ubi_rb_for_each_entry() in unmap_peb()
  ...

ubi: Fix Fastmap's update_vol()

2016-10-02T20:55:02+00:00

Usually Fastmap is free to consider every PEB in one of the pools
as newer than the existing PEB. Since PEBs in a pool are by definition
newer than everything else.
But update_vol() missed the case that a pool can contain more than
one candidate.

Cc: 
Fixes: dbb7d2a88d ("UBI: Add fastmap core")
Signed-off-by: Richard Weinberger 
Reviewed-by: Boris Brezillon 
Signed-off-by: Richard Weinberger

ubi: Fix races around ubi_refill_pools()

2016-10-02T20:54:01+00:00

When writing a new Fastmap the first thing that happens
is refilling the pools in memory.
At this stage it is possible that new PEBs from the new pools
get already claimed and written with data.
If this happens before the new Fastmap data structure hits the
flash and we face power cut the freshly written PEB will not
scanned and unnoticed.

Solve the issue by locking the pools until Fastmap is written.

Cc: 
Fixes: dbb7d2a88d ("UBI: Add fastmap core")
Signed-off-by: Richard Weinberger

ubi: Deal with interrupted erasures in WL

2016-10-02T20:49:54+00:00

When Fastmap is used we can face here an -EBADMSG
since Fastmap cannot know about unmaps.
If the erasure was interrupted the PEB may show ECC
errors and UBI would go to ro-mode as it assumes
that the PEB was check during attach time, which is
not the case with Fastmap.

Cc: 
Fixes: dbb7d2a88d ("UBI: Add fastmap core")
Signed-off-by: Richard Weinberger