1
Commit Graph

122 Commits

Author SHA1 Message Date
Dominique Martinet
be2ca38253 Revert "fs/9p: simplify iget to remove unnecessary paths"
This reverts commit 724a08450f.

This code simplification introduced significant regressions on servers
that do not remap inode numbers when exporting multiple underlying
filesystems with colliding inodes, as can be illustrated with simple
tmpfs exports in qemu with remapping disabled:
```
# host side
cd /tmp/linux-test
mkdir m1 m2
mount -t tmpfs tmpfs m1
mount -t tmpfs tmpfs m2
mkdir m1/dir m2/dir
echo foo > m1/dir/foo
echo bar > m2/dir/bar

# guest side
# started with -virtfs local,path=/tmp/linux-test,mount_tag=tmp,security_model=mapped-file
mount -t 9p -o trans=virtio,debug=1 tmp /mnt/t

ls /mnt/t/m1/dir
# foo
ls /mnt/t/m2/dir
# bar (works ok if directry isn't open)

# cd to keep first dir's inode alive
cd /mnt/t/m1/dir
ls /mnt/t/m2/dir
# foo (should be bar)
```
Other examples can be crafted with regular files with fscache enabled,
in which case I/Os just happen to the wrong file leading to
corruptions, or guest failing to boot with:
  | VFS: Lookup of 'com.android.runtime' in 9p 9p would have caused loop

In theory, we'd want the servers to be smart enough and ensure they
never send us two different files with the same 'qid.path', but while
qemu has an option to remap that is recommended (and qemu prints a
warning if this case happens), there are many other servers which do
not (kvmtool, nfs-ganesha, probably diod...), we should at least ensure
we don't cause regressions on this:
- assume servers can't be trusted and operations that should get a 'new'
inode properly do so. commit d05dcfdf5e (" fs/9p: mitigate inode
collisions") attempted to do this, but v9fs_fid_iget_dotl() was not
called so some higher level of caching got in the way; this needs to be
fixed properly before we can re-apply the patches.
- if we ever want to really simplify this code, we will need to add some
negotiation with the server at mount time where the server could claim
they handle this properly, at which point we could optimize this out.
(but that might not be needed at all if we properly handle the 'new'
check?)

Fixes: 724a08450f ("fs/9p: simplify iget to remove unnecessary paths")
Reported-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/all/20240408141436.GA17022@redhat.com/
Link: https://lkml.kernel.org/r/20240923100508.GA32066@willie-the-truck
Cc: stable@vger.kernel.org # v6.9+
Message-ID: <20241024-revert_iget-v1-4-4cac63d25f72@codewreck.org>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-10-25 06:26:09 +09:00
Dominique Martinet
f69999b5f9 Revert " fs/9p: mitigate inode collisions"
This reverts commit d05dcfdf5e.

This is a requirement to revert commit 724a08450f ("fs/9p: simplify
iget to remove unnecessary paths"), see that revert for details.

Fixes: 724a08450f ("fs/9p: simplify iget to remove unnecessary paths")
Reported-by: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20240923100508.GA32066@willie-the-truck
Cc: stable@vger.kernel.org # v6.9+
Message-ID: <20241024-revert_iget-v1-1-4cac63d25f72@codewreck.org>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-10-25 06:26:08 +09:00
Eric Van Hensbergen
d05dcfdf5e
fs/9p: mitigate inode collisions
Detect and mitigate inode collsions that now occur since we
fixed 9p generating duplicate inode structures.  Underlying
cause of these appears to be a race condition between reuse
of inode numbers in underlying file system and cleanup of
inode numbers in the client.  Enabling caching
makes this much more likely to happen as it increases cleanup
latency due to writebacks.

Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-04-22 15:34:27 +00:00
Joakim Sindholt
7fd524b9bd
fs/9p: drop inodes immediately on non-.L too
Signed-off-by: Joakim Sindholt <opensource@zhasha.com>
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-04-11 23:40:55 +00:00
Eric Van Hensbergen
824f06ff81
fs/9p: Revert "fs/9p: fix dups even in uncached mode"
This reverts commit be57855f50.

It caused a regression involving duplicate inode numbers in
some tester trees.  The bad behavior seems to be dependent on inode
reuse policy in underlying file system, so it did not trigger in my
test setup.

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-04-11 23:36:33 +00:00
Eric Van Hensbergen
be57855f50
fs/9p: fix dups even in uncached mode
In uncached mode we were still seeing duplicate getattr requests
because of aggressive dropping of inodes.  Inode "freshness" is
guarded by other mechanisms when caches are disabled so this
is unnecessary and increases overhead of almost every operation.

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-01-26 16:46:56 +00:00
Eric Van Hensbergen
724a08450f
fs/9p: simplify iget to remove unnecessary paths
Remove the additional comparison operators and switch to
simply lookup by inode number (aka qid.path).

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-01-26 16:46:56 +00:00
Eric Van Hensbergen
fe1371d0f8
fs/9p: switch vfsmount to use v9fs_get_new_inode
In the process of cleaning up inode number allocation, I noticed several functions which didn't use the standard helper
allocators.  This patch fixes the allocation in the mount entrypoint.

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-01-26 16:46:55 +00:00
David Howells
c9c4ff12df netfs: Move pinning-for-writeback from fscache to netfs
Move the resource pinning-for-writeback from fscache code to netfslib code.
This is used to keep a cache backing object pinned whilst we have dirty
pages on the netfs inode in the pagecache such that VM writeback will be
able to reach it.

Whilst we're at it, switch the parameters of netfs_unpin_writeback() to
match ->write_inode() so that it can be used for that directly.

Note that this mechanism could be more generically useful than that for
network filesystems.  Quite often they have to keep around other resources
(e.g. authentication tokens or network connections) until the writeback is
complete.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
2023-12-24 15:08:49 +00:00
Linus Torvalds
ed23734c23 Including fixes from netfilter.
Current release - regressions:
 
  - sched: act_pedit: free pedit keys on bail from offset check
 
 Current release - new code bugs:
 
  - pds_core:
   - Kconfig fixes (DEBUGFS and AUXILIARY_BUS)
   - fix mutex double unlock in error path
 
 Previous releases - regressions:
 
  - sched: cls_api: remove block_cb from driver_list before freeing
 
  - nf_tables: fix ct untracked match breakage
 
  - eth: mtk_eth_soc: drop generic vlan rx offload
 
  - sched: flower: fix error handler on replace
 
 Previous releases - always broken:
 
  - tcp: fix skb_copy_ubufs() vs BIG TCP
 
  - ipv6: fix skb hash for some RST packets
 
  - af_packet: don't send zero-byte data in packet_sendmsg_spkt()
 
  - rxrpc: timeout handling fixes after moving client call connection
    to the I/O thread
 
  - ixgbe: fix panic during XDP_TX with > 64 CPUs
 
  - igc: RMW the SRRCTL register to prevent losing timestamp config
 
  - dsa: mt7530: fix corrupt frames using TRGMII on 40 MHz XTAL MT7621
 
  - r8152:
    - fix flow control issue of RTL8156A
    - fix the poor throughput for 2.5G devices
    - move setting r8153b_rx_agg_chg_indicate() to fix coalescing
    - enable autosuspend
 
  - ncsi: clear Tx enable mode when handling a Config required AEN
 
  - octeontx2-pf: macsec: fixes for CN10KB ASIC rev
 
 Misc:
 
  - 9p: remove INET dependency
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE6jPA+I1ugmIBA4hXMUZtbf5SIrsFAmRVeUIACgkQMUZtbf5S
 IrtTug/9Hhg/L0PTSwrfuGh4W1/cjheMWppNLkwyWQUiKG7FcZQ9vu9PxceE3VRu
 2fTqHyvgDMZ8jACovXObeda8z1+g3s/tIPaXELephBIjVlF/h3kG2OaIzlU4jDb4
 A4vklwf8eLbfyVBG22QgKl/I70zVMtnmnOo6c6CPuIOTcMPzslndFO9tB0nCg99F
 DCgCM1BBP1tz+OUch2rLnSzYcqkWqS49BhRk6dhYSliawUFU/5+1tDGDjwWolkfm
 0jqP9DjBOSpZKO8m7SpsUNz7NFRIfYErWZ+YebWbggNxj/6TRJTP83MM0tGoK1rE
 /mz2xpuOki59frlwVOAD6gb/qefjHUp21P4NA7bnhizxFlQL5MHpCeGQ9yLHBSmY
 9Q4ArJkM4jXQ0oDA2nII/pz+cDZGEWFGQ14WW3kYUb7WFmISH4I9OiA9i0TBW6OL
 r1Y/rqzkUvtKWzh9RpiAF9lsdHAm3SX9ES5RfMxzv0x886VOZR4jaMmokRDdPRzq
 0r2Oyj75b62+X0r44Fe22Pl/kPS/uh3642xo9h85aAv/EvhT9JNzMvomJm9d6tkb
 966I085AVbwxPAy+rl5SWyAq60EWDExNTjZvPv0mSMlmSsQ9iK5//xOF2Saw2zai
 /44zQ27tVGkCC44Ou5KmfJN3u4OrKkhcuyxtcDr9QeoOdKZRkMg=
 =9xND
 -----END PGP SIGNATURE-----

Merge tag 'net-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from netfilter.

  Current release - regressions:

   - sched: act_pedit: free pedit keys on bail from offset check

  Current release - new code bugs:

   - pds_core:
      - Kconfig fixes (DEBUGFS and AUXILIARY_BUS)
      - fix mutex double unlock in error path

  Previous releases - regressions:

   - sched: cls_api: remove block_cb from driver_list before freeing

   - nf_tables: fix ct untracked match breakage

   - eth: mtk_eth_soc: drop generic vlan rx offload

   - sched: flower: fix error handler on replace

  Previous releases - always broken:

   - tcp: fix skb_copy_ubufs() vs BIG TCP

   - ipv6: fix skb hash for some RST packets

   - af_packet: don't send zero-byte data in packet_sendmsg_spkt()

   - rxrpc: timeout handling fixes after moving client call connection
     to the I/O thread

   - ixgbe: fix panic during XDP_TX with > 64 CPUs

   - igc: RMW the SRRCTL register to prevent losing timestamp config

   - dsa: mt7530: fix corrupt frames using TRGMII on 40 MHz XTAL MT7621

   - r8152:
      - fix flow control issue of RTL8156A
      - fix the poor throughput for 2.5G devices
      - move setting r8153b_rx_agg_chg_indicate() to fix coalescing
      - enable autosuspend

   - ncsi: clear Tx enable mode when handling a Config required AEN

   - octeontx2-pf: macsec: fixes for CN10KB ASIC rev

  Misc:

   - 9p: remove INET dependency"

* tag 'net-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (69 commits)
  net: bcmgenet: Remove phy_stop() from bcmgenet_netif_stop()
  pds_core: fix mutex double unlock in error path
  net/sched: flower: fix error handler on replace
  Revert "net/sched: flower: Fix wrong handle assignment during filter change"
  net/sched: flower: fix filter idr initialization
  net: fec: correct the counting of XDP sent frames
  bonding: add xdp_features support
  net: enetc: check the index of the SFI rather than the handle
  sfc: Add back mailing list
  virtio_net: suppress cpu stall when free_unused_bufs
  ice: block LAN in case of VF to VF offload
  net: dsa: mt7530: fix network connectivity with multiple CPU ports
  net: dsa: mt7530: fix corrupt frames using trgmii on 40 MHz XTAL MT7621
  9p: Remove INET dependency
  netfilter: nf_tables: fix ct untracked match breakage
  af_packet: Don't send zero-byte data in packet_sendmsg_spkt().
  igc: read before write to SRRCTL register
  pds_core: add AUXILIARY_BUS and NET_DEVLINK to Kconfig
  pds_core: remove CONFIG_DEBUG_FS from makefile
  ionic: catch failure from devlink_alloc
  ...
2023-05-05 19:12:01 -07:00
Jason Andryuk
d7385ba137 9p: Remove INET dependency
9pfs can run over assorted transports, so it doesn't have an INET
dependency.  Drop it and remove the includes of linux/inet.h.

NET_9P_FD/trans_fd.o builds without INET or UNIX and is usable over
plain file descriptors.  However, tcp and unix functionality is still
built and would generate runtime failures if used.  Add imply INET and
UNIX to NET_9P_FD, so functionality is enabled by default but can still
be explicitly disabled.

This allows configuring 9pfs over Xen with INET and UNIX disabled.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-04 21:46:57 +01:00
Eric Van Hensbergen
4eb3117888
fs/9p: Rework cache modes and add new options to Documentation
Switch cache modes to a bit-mask and use legacy
cache names as shortcuts.  Update documentation to
include information on both shortcuts and bitmasks.

This patch also fixes missing guards related to fscache.

Update the documentation for new mount flags
and cache modes.

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2023-04-09 21:41:21 +00:00
Eric Van Hensbergen
1543b4c507
fs/9p: remove writeback fid and fix per-file modes
This patch removes the creating of an additional writeback_fid
for opened files.  The patch addresses problems when files
were opened write-only or getattr on files with dirty caches.

This patch also incorporates information about cache behavior
in the fid for every file.  This allows us to reflect cache
behavior from mount flags, open mode, and information from
the server to inform readahead and writeback behavior.

This includes adding support for a 9p semantic that qid.version==0
is used to mark a file as non-cachable which is important for
synthetic files.  This may have a side-effect of not supporting
caching on certain legacy file servers that do not properly set
qid.version.  There is also now a mount flag which can disable
the qid.version behavior.

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2023-03-27 02:33:48 +00:00
Eric Van Hensbergen
8142db4f27
fs/9p: allow disable of xattr support on mount
xattr creates a lot of additional messages for 9p in
the current implementation.  This allows users to
conditionalize xattr support on 9p mount if they
are on a connection with bad latency.  Using this
flag is also useful when debugging other aspects
of 9p as it reduces the noise in the trace files.

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
Reviewed-by: Dominique Martinet <asmadeus@codewreck.org>
2023-03-27 02:33:48 +00:00
Eric Van Hensbergen
740b8bf873
fs/9p: Remove unnecessary superblock flags
These flags just add unnecessary extra operations.
When 9p is run without cache, it inherently implements
these options so we don't need them in the superblock
(which ends up sending extraneous fsyncs, etc.).  User
can still request these options on mount, but we don't
need to set them as default.

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2023-03-27 02:33:47 +00:00
Christophe JAILLET
6e0149a553 9p/fs: Remove unneeded idr.h #include
The 9p fs does not use IDR or IDA functionalities. So there is no point in
including <linux/idr.h>.
Remove it.

Link: https://lkml.kernel.org/r/3d1e0ed9714eaee7e18d9f5b0b4bfa49b00b286d.1669553950.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
[Dominique: reword subject]
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-12-02 23:59:15 +09:00
Dominique Martinet
dafbe68973 9p fid refcount: cleanup p9_fid_put calls
Simplify p9_fid_put cleanup path in many 9p functions since the function
is noop on null or error fids.

Also make the *_add_fid() helpers "steal" the fid by nulling its
pointer, so put after them will be noop.

This should lead to no change of behaviour

Link: https://lkml.kernel.org/r/20220612085330.1451496-7-asmadeus@codewreck.org
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-07-02 18:52:21 +09:00
Dominique Martinet
b48dbb998d 9p fid refcount: add p9_fid_get/put wrappers
I was recently reminded that it is not clear that p9_client_clunk()
was actually just decrementing refcount and clunking only when that
reaches zero: make it clear through a set of helpers.

This will also allow instrumenting refcounting better for debugging
next patch

Link: https://lkml.kernel.org/r/20220612085330.1451496-5-asmadeus@codewreck.org
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-07-02 18:52:21 +09:00
David Howells
93c846143d 9p: Copy local writes to the cache when writing to the server
When writing to the server from v9fs_vfs_writepage(), copy the data to the
cache object too.

To make this possible, the cookie must have its active users count
incremented when the page is dirtied and kept incremented until we manage
to clean up all the pages.  This allows the writeback to take place after
the last file struct is released.

This is done by taking a use on the cookie in v9fs_set_page_dirty() if we
haven't already done so (controlled by the I_PINNING_FSCACHE_WB flag) and
dropping the pin in v9fs_write_inode() if __writeback_single_inode() clears
all the outstanding dirty pages (conveyed by the unpinned_fscache_wb flag
in the writeback_control struct).

Inode eviction must also clear the flag after truncating away all the
outstanding pages.

In the future this will be handled more gracefully by netfslib.

Changes
=======
ver #3:
 - Canonicalise the coherency data to make it endianness-independent.

ver #2:
 - Fix an unused-var warning due to CONFIG_9P_FSCACHE=n[1].

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Dominique Martinet <asmadeus@codewreck.org>
cc: Eric Van Hensbergen <ericvh@gmail.com>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: v9fs-developer@lists.sourceforge.net
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819667027.215744.13815687931204222995.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906978015.143852.10646669694345706328.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967180760.1823006.5831751873616248910.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021574522.640689.13849966660182529125.stgit@warthog.procyon.org.uk/ # v4
2022-01-10 11:53:25 +00:00
Dominique Martinet
6e195b0f7c 9p: fix a bunch of checkpatch warnings
Sohaib Mohamed started a serie of tiny and incomplete checkpatch fixes but
seemingly stopped halfway -- take over and do most of it.
This is still missing net/9p/trans* and net/9p/protocol.c for a later
time...

Link: http://lkml.kernel.org/r/20211102134608.1588018-3-dominique.martinet@atmark-techno.com
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-11-04 21:04:25 +09:00
Dominique Martinet
b1843d2385 9p: set readahead and io size according to maxsize
having a readahead of 128k with a msize of 128k (with overhead) lead to
reading 124+4k everytime, making two roundtrips needlessly.

tune readahead according to msize when cache is enabled for better
performance

Link: http://lkml.kernel.org/r/20211104120323.2189376-1-asmadeus@codewreck.org
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-11-04 21:04:04 +09:00
Dominique Martinet
024b7d6a43 9p: fix file headers
- add missing SPDX-License-Identifier
- remove (sometimes incorrect) file name from file header

Link: http://lkml.kernel.org/r/20211102134608.1588018-2-dominique.martinet@atmark-techno.com
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-11-03 17:45:04 +09:00
Jianyong Wu
6636b6dcc3 9p: add refcount to p9_fid struct
Fix race issue in fid contention.

Eric's and Greg's patch offer a mechanism to fix open-unlink-f*syscall
bug in 9p. But there is race issue in fid parallel accesses.
As Greg's patch stores all of fids from opened files into according inode,
so all the lookup fid ops can retrieve fid from inode preferentially. But
there is no mechanism to handle the fid contention issue. For example,
there are two threads get the same fid in the same time and one of them
clunk the fid before the other thread ready to discard the fid. In this
scenario, it will lead to some fatal problems, even kernel core dump.

I introduce a mechanism to fix this race issue. A counter field introduced
into p9_fid struct to store the reference counter to the fid. When a fid
is allocated from the inode or dentry, the counter will increase, and
will decrease at the end of its occupation. It is guaranteed that the
fid won't be clunked before the reference counter go down to 0, then
we can avoid the clunked fid to be used.

tests:
race issue test from the old test case:
for file in {01..50}; do touch f.${file}; done
seq 1 1000 | xargs -n 1 -P 50 -I{} cat f.* > /dev/null

open-unlink-f*syscall test:
I have tested for f*syscall include: ftruncate fstat fchown fchmod faccessat.

Link: http://lkml.kernel.org/r/20200923141146.90046-5-jianyong.wu@arm.com
Fixes: 478ba09edc ("fs/9p: search open fids first")
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2020-11-19 17:20:39 +01:00
Linus Torvalds
0eac1102e9 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Assorted stuff all over the place (the largest group here is
  Christoph's stat cleanups)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: remove KSTAT_QUERY_FLAGS
  fs: remove vfs_stat_set_lookup_flags
  fs: move vfs_fstatat out of line
  fs: implement vfs_stat and vfs_lstat in terms of vfs_fstatat
  fs: remove vfs_statx_fd
  fs: omfs: use kmemdup() rather than kmalloc+memcpy
  [PATCH] reduce boilerplate in fsid handling
  fs: Remove duplicated flag O_NDELAY occurring twice in VALID_OPEN_FLAGS
  selftests: mount: add nosymfollow tests
  Add a "nosymfollow" mount option.
2020-10-24 12:26:05 -07:00
Christoph Hellwig
55b2598e84 bdi: initialize ->ra_pages and ->io_pages in bdi_init
Set up a readahead size by default, as very few users have a good
reason to change it.  This means code, ecryptfs, and orangefs now
set up the values while they were previously missing it, while ubifs,
mtd and vboxsf manually set it to 0 to avoid readahead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Richard Weinberger <richard@nod.at> [ubifs, mtd]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-24 13:43:39 -06:00
Al Viro
6d1349c769 [PATCH] reduce boilerplate in fsid handling
Get rid of boilerplate in most of ->statfs()
instances...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-09-18 16:45:50 -04:00
Linus Torvalds
9977b1a714 9p pull request for inclusion in 5.4
Small fixes all around:
  - avoid overlayfs copy-up for PRIVATE mmaps
  - KUMSAN uninitialized warning for transport error
  - one syzbot memory leak fix in 9p cache
  - internal API cleanup for v9fs_fill_super
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE/IPbcYBuWt0zoYhOq06b7GqY5nAFAl2OG0MACgkQq06b7GqY
 5nB21Q/+P4kD+wBg4d1b74Mf+oK2p2cSvCnYHcwMgkRsuyFgu7JXLSuRy2DLlAa4
 F+92x0jvit+yUy8bFqlEsSGGmE/dZC3WfpBOVChZRT/9ZLcxNasowtGDaySrX1e1
 tmx5QfYsNL840Cv8Vfos4QJjze1oE6RmSCUUO4KyC250PO/jxEgWGVPv1S8LfTUb
 KyhkcKlJ+TCqEON9nZ+CrQ4rndHNc7LxtBjVR0M03UYW55kYAhMLSj/AWqKA5I0q
 tARlTSgHHRdj4EJvWvLw7INg7BuvTuuyIzCIo/RfpUvijTDyLXFQI3qgtXosKLSq
 wuOacq8ykDRv8nvpLJ98daCw0pQOF2Qw40niFfl8Y7AxnaXggMI+UsVX/BnigVWX
 E6kaJm6d/YERee/f7aBsJkjKbwRqO7tMbNDrbK2/AzAaZo92dnB5nsEJnvKtCdjl
 aylBujCJq/DPp/SOf0Rl8mr24GdYVIk04hvqpxr4X6a/sacO3EUMh8GkGD7muY63
 axbYildLQHyChEn0TNdicFFrVie3A984eiK8sht+visd7c5QRm9iu1lsYtXdVGuz
 0OvSRtJuTDCTs6s1DhhVnez9luzH4VZJAj0RYJjcF1M4tzy0sKWUSSUf3RUbyxmY
 bocklihTlI5UzZfCP/wChXJ26+QrmcL7j0PrKA0NJy7ooFyT5eI=
 =VBrx
 -----END PGP SIGNATURE-----

Merge tag '9p-for-5.4' of git://github.com/martinetd/linux

Pull 9p updates from Dominique Martinet:
 "Some of the usual small fixes and cleanup.

  Small fixes all around:
   - avoid overlayfs copy-up for PRIVATE mmaps
   - KUMSAN uninitialized warning for transport error
   - one syzbot memory leak fix in 9p cache
   - internal API cleanup for v9fs_fill_super"

* tag '9p-for-5.4' of git://github.com/martinetd/linux:
  9p/vfs_super.c: Remove unused parameter data in v9fs_fill_super
  9p/cache.c: Fix memory leak in v9fs_cache_session_get_cookie
  9p: Transport error uninitialized
  9p: avoid attaching writeback_fid on mmap with type PRIVATE
2019-09-27 15:10:34 -07:00
Bharath Vedartham
aafee43b72 9p/vfs_super.c: Remove unused parameter data in v9fs_fill_super
v9fs_fill_super has a param 'void *data' which is unused in the
function.

This patch removes the 'void *data' param in v9fs_fill_super and changes
the parameters in all function calls of v9fs_fill_super.

Link: http://lkml.kernel.org/r/20190523165619.GA4209@bharath12345-Inspiron-5559
Signed-off-by: Bharath Vedartham <linux.bhar@gmail.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2019-09-03 11:10:13 +00:00
Deepa Dinamani
d5c6e2d518 9p: Fill min and max timestamps in sb
struct p9_wstat and struct p9_stat_dotl indicate that the
wire transport uses u32 and u64 fields for timestamps.
Fill in the appropriate limits to avoid inconsistencies in
the vfs cached inode times when timestamps are outside the
permitted range.

Note that the upper bound for V9FS_PROTO_2000L is retained as S64_MAX.
This is because that is the upper bound supported by vfs.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Cc: ericvh@gmail.com
Cc: lucho@ionkov.net
Cc: asmadeus@codewreck.org
Cc: v9fs-developer@lists.sourceforge.net
2019-08-30 07:27:18 -07:00
Thomas Gleixner
1f32761322 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 188
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to free software
  foundation 51 franklin street fifth floor boston ma 02111 1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 27 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170026.981318839@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:29:21 -07:00
Al Viro
5e8a0770c0 9p: switch to ->free_inode()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-01 22:43:23 -04:00
Linus Torvalds
db77bef53b Pull request for inlusion in 5.1
Two fixes (leak on invalid mount argument and possible deadlock on
 i_size update on 32bit smp) and a fall-through warning cleanup
 
 ----------------------------------------------------------------
 Gustavo A. R. Silva (1):
       9p: mark expected switch fall-through
 
 Hou Tao (1):
       9p: use inode->i_lock to protect i_size_write() under 32-bit
 
 zhengbin (1):
       9p/net: fix memory leak in p9_client_create
 
  fs/9p/v9fs_vfs.h       | 23 +++++++++++++++++++++--
  fs/9p/vfs_file.c       |  6 +++++-
  fs/9p/vfs_inode.c      | 23 +++++++++++------------
  fs/9p/vfs_inode_dotl.c | 27 ++++++++++++++-------------
  fs/9p/vfs_super.c      |  4 ++--
  net/9p/client.c        |  2 +-
  net/9p/trans_xen.c     |  2 +-
  7 files changed, 55 insertions(+), 32 deletions(-)
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE/IPbcYBuWt0zoYhOq06b7GqY5nAFAlyOVo4ACgkQq06b7GqY
 5nC7tQ//SJfSH6ooQE6nZywokUKpgXSzEPKHI6krI2lj8XuqL5r6iSQMqKwaWXFt
 h2onfPKtp+SHJaCnW82G9P54IvmiS9sMt6kRzGvFR0Gz93Cy4koIRc2TmAZLIw3N
 Gmyb7oEzUSmH8mJMt0qrlyxTzQEMhainWjod4QSmwuhJe9rndox+aBsNnFb7UOJw
 2bbV8T2j8amrF124VkK8wsglIpbKGJjDBAsfZ1ZHaWks2XqaNGDIvSIXse38WUhi
 rmOswBo1ZJBqS/FyojWW9hhtGmGSM9TgAzNdMABAZvjgmoWCk4xyO/6H95O8iL6Q
 Jp4XevUBcdwJWSp9VKeILLOyGx2UjkYy3KLuLnwyQUATDqDf+avdaiZC+Z0P/ulC
 l1fHgqK5E1wks328OvtO+kjFGqgiGzXfE1MnEmbFopvX3nqBr0yx8w4GdYm9irb9
 7PKz7HoGkOVuwhveNAQHR/Q58Mc/kxfOKvoRb19r5cM+pynFbWL9p4kFtG2Wc7sE
 y2xZ9jKKvoTh6BmAfkQTwJmGWDYWr3iSTq3YF5B7bNd8S9omzlY0e0PxOs0NHfMb
 wCoZhBRTAdv2NJvN2Q2nQeCFYPjCA7mnarDTVI3F+CwgGsbEFdCqi6B/H7aNcvv8
 uVm31guy2Df45ySL1FCz+sQdXIZBRS7+S38ufKXGlKERBIeEsCQ=
 =q3cR
 -----END PGP SIGNATURE-----

Merge tag '9p-for-5.1' of git://github.com/martinetd/linux

Pull 9p updates from Dominique Martinet:
 "Here is a 9p update for 5.1; there honestly hasn't been much.

  Two fixes (leak on invalid mount argument and possible deadlock on
  i_size update on 32bit smp) and a fall-through warning cleanup"

* tag '9p-for-5.1' of git://github.com/martinetd/linux:
  9p/net: fix memory leak in p9_client_create
  9p: use inode->i_lock to protect i_size_write() under 32-bit
  9p: mark expected switch fall-through
2019-03-17 09:10:56 -07:00
Nikolay Borisov
b5420237ec mm: refactor readahead defines in mm.h
All users of VM_MAX_READAHEAD actually convert it to kbytes and then to
pages. Define the macro explicitly as (SZ_128K / PAGE_SIZE). This
simplifies the expression in every filesystem. Also rename the macro to
VM_READAHEAD_PAGES to properly convey its meaning. Finally remove unused
VM_MIN_READAHEAD

[akpm@linux-foundation.org: fix fs/io_uring.c, per Stephen]
Link: http://lkml.kernel.org/r/20181221144053.24318-1-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-12 10:04:01 -07:00
Hou Tao
5e3cc1ee14 9p: use inode->i_lock to protect i_size_write() under 32-bit
Use inode->i_lock to protect i_size_write(), else i_size_read() in
generic_fillattr() may loop infinitely in read_seqcount_begin() when
multiple processes invoke v9fs_vfs_getattr() or v9fs_vfs_getattr_dotl()
simultaneously under 32-bit SMP environment, and a soft lockup will be
triggered as show below:

  watchdog: BUG: soft lockup - CPU#5 stuck for 22s! [stat:2217]
  Modules linked in:
  CPU: 5 PID: 2217 Comm: stat Not tainted 5.0.0-rc1-00005-g7f702faf5a9e #4
  Hardware name: Generic DT based system
  PC is at generic_fillattr+0x104/0x108
  LR is at 0xec497f00
  pc : [<802b8898>]    lr : [<ec497f00>]    psr: 200c0013
  sp : ec497e20  ip : ed608030  fp : ec497e3c
  r10: 00000000  r9 : ec497f00  r8 : ed608030
  r7 : ec497ebc  r6 : ec497f00  r5 : ee5c1550  r4 : ee005780
  r3 : 0000052d  r2 : 00000000  r1 : ec497f00  r0 : ed608030
  Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
  Control: 10c5387d  Table: ac48006a  DAC: 00000051
  CPU: 5 PID: 2217 Comm: stat Not tainted 5.0.0-rc1-00005-g7f702faf5a9e #4
  Hardware name: Generic DT based system
  Backtrace:
  [<8010d974>] (dump_backtrace) from [<8010dc88>] (show_stack+0x20/0x24)
  [<8010dc68>] (show_stack) from [<80a1d194>] (dump_stack+0xb0/0xdc)
  [<80a1d0e4>] (dump_stack) from [<80109f34>] (show_regs+0x1c/0x20)
  [<80109f18>] (show_regs) from [<801d0a80>] (watchdog_timer_fn+0x280/0x2f8)
  [<801d0800>] (watchdog_timer_fn) from [<80198658>] (__hrtimer_run_queues+0x18c/0x380)
  [<801984cc>] (__hrtimer_run_queues) from [<80198e60>] (hrtimer_run_queues+0xb8/0xf0)
  [<80198da8>] (hrtimer_run_queues) from [<801973e8>] (run_local_timers+0x28/0x64)
  [<801973c0>] (run_local_timers) from [<80197460>] (update_process_times+0x3c/0x6c)
  [<80197424>] (update_process_times) from [<801ab2b8>] (tick_nohz_handler+0xe0/0x1bc)
  [<801ab1d8>] (tick_nohz_handler) from [<80843050>] (arch_timer_handler_virt+0x38/0x48)
  [<80843018>] (arch_timer_handler_virt) from [<80180a64>] (handle_percpu_devid_irq+0x8c/0x240)
  [<801809d8>] (handle_percpu_devid_irq) from [<8017ac20>] (generic_handle_irq+0x34/0x44)
  [<8017abec>] (generic_handle_irq) from [<8017b344>] (__handle_domain_irq+0x6c/0xc4)
  [<8017b2d8>] (__handle_domain_irq) from [<801022e0>] (gic_handle_irq+0x4c/0x88)
  [<80102294>] (gic_handle_irq) from [<80101a30>] (__irq_svc+0x70/0x98)
  [<802b8794>] (generic_fillattr) from [<8056b284>] (v9fs_vfs_getattr_dotl+0x74/0xa4)
  [<8056b210>] (v9fs_vfs_getattr_dotl) from [<802b8904>] (vfs_getattr_nosec+0x68/0x7c)
  [<802b889c>] (vfs_getattr_nosec) from [<802b895c>] (vfs_getattr+0x44/0x48)
  [<802b8918>] (vfs_getattr) from [<802b8a74>] (vfs_statx+0x9c/0xec)
  [<802b89d8>] (vfs_statx) from [<802b9428>] (sys_lstat64+0x48/0x78)
  [<802b93e0>] (sys_lstat64) from [<80101000>] (ret_fast_syscall+0x0/0x28)

[dominique.martinet@cea.fr: updated comment to not refer to a function
in another subsystem]
Link: http://lkml.kernel.org/r/20190124063514.8571-2-houtao1@huawei.com
Cc: stable@vger.kernel.org
Fixes: 7549ae3e81 ("9p: Use the i_size_[read, write]() macros instead of using inode->i_size directly.")
Reported-by: Xing Gaopeng <xingaopeng@huawei.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2019-03-03 14:04:07 +09:00
Yiwen Jiang
7ff3c20468 fs/9p: don't set SB_NOATIME by default
When the user uses some syscall, for example mmap(v9fs_file_mmap), it
will not update atime even if user's was set mnt_flags without
MNT_NOATIME, because v9fs defaults to settine SB_NOATIME in
v9fs_set_super.

For supporting access time updating when the user mounts with relatime,
we should not set SB_NOATIME by default.

Link: http://lkml.kernel.org/r/5AB9A377.6080906@huawei.com
Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-05 21:36:22 -07:00
Linus Torvalds
1751e8a6cb Rename superblock flags (MS_xyz -> SB_xyz)
This is a pure automated search-and-replace of the internal kernel
superblock flags.

The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.

Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.

The script to do this was:

    # places to look in; re security/*: it generally should *not* be
    # touched (that stuff parses mount(2) arguments directly), but
    # there are two places where we really deal with superblock flags.
    FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
            include/linux/fs.h include/uapi/linux/bfs_fs.h \
            security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
    # the list of MS_... constants
    SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
          DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
          POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
          I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
          ACTIVE NOUSER"

    SED_PROG=
    for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done

    # we want files that contain at least one of MS_...,
    # with fs/namespace.c and fs/pnode.c excluded.
    L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')

    for f in $L; do sed -i $f $SED_PROG; done

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-27 13:05:09 -08:00
David Howells
c4fac91004 9p: Implement show_options
Implement the show_options superblock op for 9p as part of a bid to get
rid of s_options and generic_show_options() to make it easier to implement
a context-based mount where the mount options can be passed individually
over a file descriptor.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Eric Van Hensbergen <ericvh@gmail.com>
cc: Ron Minnich <rminnich@sandia.gov>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: v9fs-developer@lists.sourceforge.net
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-11 06:08:58 -04:00
Jan Kara
71304feba3 9p: Convert to separately allocated bdi
Allocate struct backing_dev_info separately instead of embedding it
inside session. This unifies handling of bdi among users.

CC: Eric Van Hensbergen <ericvh@gmail.com>
CC: Ron Minnich <rminnich@sandia.gov>
CC: Latchesar Ionkov <lucho@ionkov.net>
CC: v9fs-developer@lists.sourceforge.net
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:09:55 -06:00
Kirill A. Shutemov
09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00
Tejun Heo
412a19b64a v9fs: fix error handling in v9fs_session_init()
On failure, v9fs_session_init() returns with the v9fs_session_info
struct partially initialized and expects the caller to invoke
v9fs_session_close() to clean it up; however, it doesn't track whether
the bdi is initialized or not and curiously invokes bdi_destroy() in
both vfs_session_init() failure path too.

A. If v9fs_session_init() fails before the bdi is initialized, the
   follow-up v9fs_session_close() will invoke bdi_destroy() on an
   uninitialized bdi.

B. If v9fs_session_init() fails after the bdi is initialized,
   bdi_destroy() will be called twice on the same bdi - once in the
   failure path of v9fs_session_init() and then by
   v9fs_session_close().

A is broken no matter what.  B used to be okay because bdi_destroy()
allowed being invoked multiple times on the same bdi, which BTW was
broken in its own way - if bdi_destroy() was invoked on an initialiezd
but !registered bdi, it'd fail to free percpu counters.  Since
f0054bb1e1 ("writeback: move backing_dev_info->wb_lock and
->worklist into bdi_writeback"), this no longer work - bdi_destroy()
on an initialized but not registered bdi works correctly but multiple
invocations of bdi_destroy() is no longer allowed.

The obvious culprit here is v9fs_session_init()'s odd and broken error
behavior.  It should simply clean up after itself on failures.  This
patch makes the following updates to v9fs_session_init().

* @rc -> @retval error return propagation removed.  It didn't serve
  any purpose.  Just use @rc.

* Move addition to v9fs_sessionlist to the end of the function so that
  incomplete sessions are not put on the list or iterated and error
  path doesn't have to worry about it.

* Update error handling so that it cleans up after itself.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-08 09:05:06 -06:00
David Howells
2b0143b5c9 VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
Dominique Martinet
fb89b45cdf 9P: introduction of a new cache=mmap model.
- Add cache=mmap option
 - Make mmap read-write while keeping it as synchronous as possible
 - Build writeback fid on mmap creation if it is writable

Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2014-01-10 09:20:51 -06:00
Eric W. Biederman
7f78e03513 fs: Limit sys_mount to only request filesystem modules.
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-03 19:36:31 -08:00
Jeff Layton
ecf3d1f1aa vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
The following set of operations on a NFS client and server will cause

    server# mkdir a
    client# cd a
    server# mv a a.bak
    client# sleep 30  # (or whatever the dir attrcache timeout is)
    client# stat .
    stat: cannot stat `.': Stale NFS file handle

Obviously, we should not be getting an ESTALE error back there since the
inode still exists on the server. The problem is that the lookup code
will call d_revalidate on the dentry that "." refers to, because NFS has
FS_REVAL_DOT set.

nfs_lookup_revalidate will see that the parent directory has changed and
will try to reverify the dentry by redoing a LOOKUP. That of course
fails, so the lookup code returns ESTALE.

The problem here is that d_revalidate is really a bad fit for this case.
What we really want to know at this point is whether the inode is still
good or not, but we don't really care what name it goes by or whether
the dcache is still valid.

Add a new d_op->d_weak_revalidate operation and have complete_walk call
that instead of d_revalidate. The intent there is to allow for a
"weaker" d_revalidate that just checks to see whether the inode is still
good. This is also gives us an opportunity to kill off the FS_REVAL_DOT
special casing.

[AV: changed method name, added note in porting, fixed confusion re
having it possibly called from RCU mode (it won't be)]

Cc: NeilBrown <neilb@suse.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-26 02:46:09 -05:00
David Howells
9249e17fe0 VFS: Pass mount flags to sget()
Pass mount flags to sget() so that it can use them in initialising a new
superblock before the set function is called.  They could also be passed to the
compare function.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:38:34 +04:00
Linus Torvalds
e9c0f1529c 9p changes for the 3.4 merge window
The following changes since commit 3c761ea05a:
 
   Fix autofs compile without CONFIG_COMPAT (2012-02-26 09:44:55 -0800)
 
 are available in the git repository at:
   git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs.git for-linus
 
 Jim Garlick (3):
       net/9p: don't allow Tflush to be interrupted
       net/9p: handle flushed Tclunk/Tremove
       9p: statfs should not override server f_type
 
  fs/9p/vfs_super.c |    2 +-
  net/9p/client.c   |   26 +++++++++++++++++++++++---
  2 files changed, 24 insertions(+), 4 deletions(-)
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG/MacGPG2 v2.0.17 (Darwin)
 Comment: GPGTools - http://gpgtools.org
 
 iQIcBAABAgAGBQJPcJNvAAoJEGQ1yQUIRaTOeDYP/2JdsCRt8SGstGgdpi9zWdDL
 GjhNguTSqfQSv+LB7mvdM49JFEFkPdZ1/Giu7nkZmYqRR6RdprYuRsiX6lQnAE49
 CFjIyQkeeMhvEvYLX10KG7WtMOicOQGHdLEIfAlHBdA8ILZDJTz+F7nB0S4EG6ST
 3TRXVoa2ojS5SVUxQSOFQsT0CM5+5K95Bnjlv57diyWNb3lkdhzXDQmmaL/OCFpE
 6Zh0+CylAaiybBxT3JjSKlchIlNh59Ei0X7S0J8wDPEzk7+PLfjhlKeyFvgC/TOp
 9yIpX1nzOm6B0l8vXXatdW9QRubIvOYTZe7mtoxpIPPWVnOTI1fhHsteBDjPA7wj
 NJeMTzDRkBWbo+ntQ53MzFsbBLlF+DuFBWFrIRc3Ov3+endDxUCEhCxSBDCj1Hd5
 /dLNvyeiQPcne+j3oKIlTQLc1HJi6EEMCNVusBhT3tm3k1FbEFfeT9YqcsuRvPlD
 ozn6tVcRkyCf184tF8rBOY1nPwk2TMLV8vrUPYOtqD/4plNLxmG6JTFcLLBLA+wE
 G4dQBknM8LCDX6mTHJAF7zkEXomjhvDK9JANQ0sOczKu47+IfAFAs2Vc55R6d6Dd
 8m2H9QlVv0DGu7yHzo0/0W5gFq2xl5/5lV6u0sDAp0jo5MmOuIPqG+oF7NVnaM3Q
 6aI9BHEZ0Dz63VD2dniY
 =Jfvn
 -----END PGP SIGNATURE-----

Merge tag 'for-linus-3.4-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs

Pull 9p changes for the 3.4 merge window from Eric Van Hensbergen.

* tag 'for-linus-3.4-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9p: statfs should not override server f_type
  net/9p: handle flushed Tclunk/Tremove
  net/9p: don't allow Tflush to be interrupted
2012-03-28 09:58:38 -07:00
Al Viro
48fde701af switch open-coded instances of d_make_root() to new helper
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:35 -04:00
Jim Garlick
5bdad93387 9p: statfs should not override server f_type
Allow a 9p2000.L server to supply the statfs f_type value rather than
hardwiring V9FS_MAGIC.  It is desirable to give the server this option
in some applications, e.g. I/O forwarding.

Signed-off-by: Jim Garlick <garlick@llnl.gov>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2012-03-10 19:34:04 -06:00
Linus Torvalds
609eac1c15 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  fs/9p: iattr_valid flags are kernel internal flags map them to 9p values.
  fs/9p: We should not allocate a new inode when creating hardlines.
  fs/9p: v9fs_stat2inode should update suid/sgid bits.
  9p: Reduce object size with CONFIG_NET_9P_DEBUG
  fs/9p: check schedule_timeout_interruptible return value

Fix up trivial conflicts in fs/9p/{vfs_inode.c,vfs_inode_dotl.c} due to
debug messages having changed to use p9_debug() on one hand, and the
changes for umode_t on the other.
2012-01-10 15:09:01 -08:00
Joe Perches
5d3851530d 9p: Reduce object size with CONFIG_NET_9P_DEBUG
Reduce object size by deduplicating formats.

Use vsprintf extension %pV.
Rename P9_DPRINTK uses to p9_debug, align arguments.
Add function for _p9_debug and macro to add __func__.
Add missing "\n"s to p9_debug uses.
Remove embedded function names as p9_debug adds it.
Remove P9_EPRINTK macro and convert use to pr_<level>.
Add and use pr_fmt and pr_<level>.

$ size fs/9p/built-in.o*
   text	   data	    bss	    dec	    hex	filename
  62133	    984	  16000	  79117	  1350d	fs/9p/built-in.o.new
  67342	    984	  16928	  85254	  14d06	fs/9p/built-in.o.old
$ size net/9p/built-in.o*
   text	   data	    bss	    dec	    hex	filename
  88792	   4148	  22024	 114964	  1c114	net/9p/built-in.o.new
  94072	   4148	  23232	 121452	  1da6c	net/9p/built-in.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2012-01-05 10:51:44 -06:00