Commit Graph

22 Commits

Author SHA1 Message Date
Scott Mayhew
75a9b91761 NFS: Fix leak of ctx->nfs_server.hostname
If userspace passes an nfs_mount_data struct in the data argument of
mount(2), then nfs23_parse_monolithic() or nfs4_parse_monolithic()
will allocate memory for ctx->nfs_server.hostname.  This needs to be
freed in nfs_parse_source(), which also allocates memory for
ctx->nfs_server.hostname, otherwise a leak will occur.

Reported-by: syzbot+193c375dcddb4f345091@syzkaller.appspotmail.com
Fixes: f2aedb713c ("NFS: Add fs_context support.")
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-02-25 13:48:21 -05:00
Scott Mayhew
1cef21842f NFS: Ensure the fs_context has the correct fs_type before mounting
This is necessary because unless userspace explicitly requests fstype
"nfs4" (either via "mount -t nfs4" or by calling the "mount.nfs4" helper
directly), the fstype will default to "nfs".

This was fine on older kernels because the super_block->s_type was set
via mount_info->nfs_mod->nfs_fs, which was set when parsing the mount
options and subsequently passed in the "type" argument of sget().

After commit f2aedb713c ("NFS: Add fs_context support."), sget_fc(),
which has no "type" argument, is called instead.  In sget_fc(), the
super_block->s_type is set via fs_context->fs_type, which was set when
the filesystem context was initially created.

Reported-by: Patrick Steinhardt <ps@pks.im>
Fixes: f2aedb713c ("NFS: Add fs_context support.")
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-02-21 15:51:04 -05:00
Al Viro
328de5287b turn fs_param_is_... into functions
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:38 -05:00
Al Viro
48ce73b1be fs_parse: handle optional arguments sanely
Don't bother with "mixed" options that would allow both the
form with and without argument (i.e. both -o foo and -o foo=bar).
Rather than trying to shove both into a single fs_parameter_spec,
allow having with-argument and no-argument specs with the same
name and teach fs_parse to handle that.

There are very few options of that sort, and they are actually
easier to handle that way - callers end up with less postprocessing.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:37 -05:00
Al Viro
d7167b1499 fs_parse: fold fs_parameter_desc/fs_parameter_spec
The former contains nothing but a pointer to an array of the latter...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:37 -05:00
Eric Sandeen
96cafb9ccb fs_parser: remove fs_parameter_description name field
Unused now.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:36 -05:00
Al Viro
5eede62529 fold struct fs_parameter_enum into struct constant_table
no real difference now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 00:12:50 -05:00
Al Viro
2710c957a8 fs_parse: get rid of ->enums
Don't do a single array; attach them to fsparam_enum() entry
instead.  And don't bother trying to embed the names into those -
it actually loses memory, with no real speedup worth mentioning.

Simplifies validation as well.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 00:12:50 -05:00
David Howells
3a21409a0b nfs: Return EINVAL rather than ERANGE for mount parse errors
Return EINVAL rather than ERANGE for mount parse errors as the userspace
mount command doesn't necessarily understand what to do with anything other
than EINVAL.

The old code returned -ERANGE as an intermediate error that then get
converted to -EINVAL, whereas the new code returns -ERANGE.

This was induced by passing minorversion=1 to a v4 mount where
CONFIG_NFS_V4_1 was disabled in the kernel build.

Fixes: 68f65ef40e1e ("NFS: Convert mount option parsing to use functionality from fs_parser.h")
Reported-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-24 16:51:13 -05:00
Olga Kornievskaia
b24ee6c64c NFS: allow deprecation of NFS UDP protocol
Add a kernel config CONFIG_NFS_DISABLE_UDP_SUPPORT to disallow NFS
UDP mounts and enable it by default.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-24 16:51:13 -05:00
Trond Myklebust
c74dfe97c1 NFS: Add mount option 'softreval'
Add a mount option 'softreval' that allows attribute revalidation 'getattr'
calls to time out, and causes them to fall back to using the cached
attributes.
The use case for this option is for ensuring that we can still (slowly)
traverse paths and use cached information even when the server is down.
Once the server comes back up again, the getattr calls start succeeding,
and the caches will revalidate as usual.

The 'softreval' mount option is automatically enabled if you have
specified 'softerr'.  It can be turned off using the options
'nosoftreval', or 'hard'.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:54:33 -05:00
Scott Mayhew
ce8866f091 NFS: Attach supplementary error information to fs_context.
Split out from commit "NFS: Add fs_context support."

Add wrappers nfs_errorf(), nfs_invalf(), and nfs_warnf() which log error
information to the fs_context.  Convert some printk's to use these new
wrappers instead.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:15:17 -05:00
Scott Mayhew
62a55d088c NFS: Additional refactoring for fs_context conversion
Split out from commit "NFS: Add fs_context support."

This patch adds additional refactoring for the conversion of NFS to use
fs_context, namely:

 (*) Merge nfs_mount_info and nfs_clone_mount into nfs_fs_context.
     nfs_clone_mount has had several fields removed, and nfs_mount_info
     has been removed altogether.
 (*) Various functions now take an fs_context as an argument instead
     of nfs_mount_info, nfs_fs_context, etc.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:15:17 -05:00
David Howells
f2aedb713c NFS: Add fs_context support.
Add filesystem context support to NFS, parsing the options in advance and
attaching the information to struct nfs_fs_context.  The highlights are:

 (*) Merge nfs_mount_info and nfs_clone_mount into nfs_fs_context.  This
     structure represents NFS's superblock config.

 (*) Make use of the VFS's parsing support to split comma-separated lists

 (*) Pin the NFS protocol module in the nfs_fs_context.

 (*) Attach supplementary error information to fs_context.  This has the
     downside that these strings must be static and can't be formatted.

 (*) Remove the auxiliary file_system_type structs since the information
     necessary can be conveyed in the nfs_fs_context struct instead.

 (*) Root mounts are made by duplicating the config for the requested mount
     so as to have the same parameters.  Submounts pick up their parameters
     from the parent superblock.

[AV -- retrans is u32, not string]
[SM -- Renamed cfg to ctx in a few functions in an earlier patch]
[SM -- Moved fs_context mount option parsing to an earlier patch]
[SM -- Moved fs_context error logging to a later patch]
[SM -- Fixed printks in nfs4_try_get_tree() and nfs4_get_referral_tree()]
[SM -- Added is_remount_fc() helper]
[SM -- Deferred some refactoring to a later patch]
[SM -- Fixed referral mounts, which were broken in the original patch]
[SM -- Fixed leak of nfs_fattr when fs_context is freed]

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:15:17 -05:00
Scott Mayhew
e38bb238ed NFS: Convert mount option parsing to use functionality from fs_parser.h
Split out from commit "NFS: Add fs_context support."

Convert existing mount option definitions to fs_parameter_enum's and
fs_parameter_spec's.  Parse mount options using fs_parse() and
lookup_constant().

Notes:

1) Fixed a typo in the udp6 definition in nfs_xprt_protocol_tokens
from the original commit.

2) fs_parse() expects an fs_context as the first arg so that any
errors can be logged to the fs_context.  We're passing NULL for the
fs_context (this will change in commit "NFS: Add fs_context support.")
which is okay as it will cause logfc() to do a printk() instead.

3) fs_parse() expects an fs_paramter as the third arg.  We're
building an fs_parameter manually in nfs_fs_context_parse_option(),
which will go away in commit "NFS: Add fs_context support.".

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:15:17 -05:00
David Howells
e558100fda NFS: Do some tidying of the parsing code
Do some tidying of the parsing code, including:

 (*) Returning 0/error rather than true/false.

 (*) Putting the nfs_fs_context pointer first in some arg lists.

 (*) Unwrap some lines that will now fit on one line.

 (*) Provide unioned sockaddr/sockaddr_storage fields to avoid casts.

 (*) nfs_parse_devname() can paste its return values directly into the
     nfs_fs_context struct as that's where the caller puts them.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:15:17 -05:00
David Howells
48be8a66cf NFS: Add a small buffer in nfs_fs_context to avoid string dup
Add a small buffer in nfs_fs_context to avoid string duplication when
parsing numbers.  Also make the parsing function wrapper place the parsed
integer directly in the appropriate nfs_fs_context struct member.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:15:17 -05:00
David Howells
cbd071b5da NFS: Deindent nfs_fs_context_parse_option()
Deindent nfs_fs_context_parse_option().

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:15:17 -05:00
David Howells
f8ee01e3e2 NFS: Split nfs_parse_mount_options()
Split nfs_parse_mount_options() to move the prologue, list-splitting and
epilogue into one function and the per-option processing into another.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:15:17 -05:00
David Howells
5eb005caf5 NFS: Rename struct nfs_parsed_mount_data to struct nfs_fs_context
Rename struct nfs_parsed_mount_data to struct nfs_fs_context and rename
pointers to it to "ctx".  At some point this will be pointed to by an
fs_context struct's fs_private pointer.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:15:17 -05:00
David Howells
e0a626b124 NFS: Constify mount argument match tables
The mount argument match tables should never be altered so constify them.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:15:17 -05:00
David Howells
9954bf92c0 NFS: Move mount parameterisation bits into their own file
Split various bits relating to mount parameterisation out from
fs/nfs/super.c into their own file to form the basis of filesystem context
handling for NFS.

No other changes are made to the code beyond removing 'static' qualifiers.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:15:17 -05:00