1. 28 Feb, 2019 14 commits
    • Al Viro's avatar
      cgroup: take options parsing into ->parse_monolithic() · f5dfb531
      Al Viro authored
      Store the results in cgroup_fs_context.  There's a nasty twist caused
      by the enabling/disabling subsystems - we can't do the checks sensitive
      to that until cgroup_mutex gets grabbed.  Frankly, these checks are
      complete bullshit (e.g. all,none combination is accepted if all subsystems
      are disabled; so's cpusets,none and all,cpusets when cpusets is disabled,
      etc.), but touching that would be a userland-visible behaviour change ;-/
      
      So we do parsing in ->parse_monolithic() and have the consistency checks
      done in check_cgroupfs_options(), with the latter called (on already parsed
      options) from cgroup1_get_tree() and cgroup1_reconfigure().
      
      Freeing the strdup'ed strings is done from fs_context destructor, which
      somewhat simplifies the life for cgroup1_{get_tree,reconfigure}().
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      f5dfb531
    • Al Viro's avatar
      7feeef58
    • Al Viro's avatar
      cgroup: start switching to fs_context · 90129625
      Al Viro authored
      Unfortunately, cgroup is tangled into kernfs infrastructure.
      To avoid converting all kernfs-based filesystems at once,
      we need to untangle the remount part of things, instead of
      having it go through kernfs_sop_remount_fs().  Fortunately,
      it's not hard to do.
      
      This commit just gets cgroup/cgroup1 to use fs_context to
      deliver options on mount and remount paths.  Parsing those
      is going to be done in the next commits; for now we do
      pretty much what legacy case does.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      90129625
    • David Howells's avatar
      ipc: Convert mqueue fs to fs_context · 935c6912
      David Howells authored
      Convert the mqueue filesystem to use the filesystem context stuff.
      
      Notes:
      
       (1) The relevant ipc namespace is selected in when the context is
           initialised (and it defaults to the current task's ipc namespace).
           The caller can override this before calling vfs_get_tree().
      
       (2) Rather than simply calling kern_mount_data(), mq_init_ns() and
           mq_internal_mount() create a context, adjust it and then do the rest
           of the mount procedure.
      
       (3) The lazy mqueue mounting on creation of a new namespace is retained
           from a previous patch, but the avoidance of sget() if no superblock
           yet exists is reverted and the superblock is again keyed on the
           namespace pointer.
      
           Yes, there was a performance gain in not searching the superblock
           hash, but it's only paid once per ipc namespace - and only if someone
           uses mqueue within that namespace, so I'm not sure it's worth it,
           especially as calling sget() allows avoidance of recursion.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      935c6912
    • David Howells's avatar
      proc: Add fs_context support to procfs · 66f592e2
      David Howells authored
      Add fs_context support to procfs.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      cc: Alexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      66f592e2
    • David Howells's avatar
      procfs: Move proc_fill_super() to fs/proc/root.c · 60a3c3a5
      David Howells authored
      Move proc_fill_super() to fs/proc/root.c as that's where the other
      superblock stuff is.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Reviewed-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
      cc: Alexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      60a3c3a5
    • Al Viro's avatar
      introduce cloning of fs_context · 0b52075e
      Al Viro authored
      new primitive: vfs_dup_fs_context().  Comes with fs_context
      method (->dup()) for copying the filesystem-specific parts
      of fs_context, along with LSM one (->fs_context_dup()) for
      doing the same to LSM parts.
      
      [needs better commit message, and change of Author:, anyway]
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      0b52075e
    • Al Viro's avatar
      convenience helpers: vfs_get_super() and sget_fc() · cb50b348
      Al Viro authored
      the former is an analogue of mount_{single,nodev} for use in
      ->get_tree() instances, the latter - analogue of sget() for the
      same.
      
      These are fairly similar to the originals, but the callback signature
      for sget_fc() is different from sget() ones, so getting bits and
      pieces shared would be too convoluted; we might get around to that
      later, but for now let's just remember to keep them in sync.  They
      do live next to each other, and changes in either won't be hard
      to spot.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      cb50b348
    • David Howells's avatar
      vfs: Implement a filesystem superblock creation/configuration context · 3e1aeb00
      David Howells authored
      [AV - unfuck kern_mount_data(); we want non-NULL ->mnt_ns on long-living
      mounts]
      [AV - reordering fs/namespace.c is badly overdue, but let's keep it
      separate from that series]
      [AV - drop simple_pin_fs() change]
      [AV - clean vfs_kern_mount() failure exits up]
      
      Implement a filesystem context concept to be used during superblock
      creation for mount and superblock reconfiguration for remount.
      
      The mounting procedure then becomes:
      
       (1) Allocate new fs_context context.
      
       (2) Configure the context.
      
       (3) Create superblock.
      
       (4) Query the superblock.
      
       (5) Create a mount for the superblock.
      
       (6) Destroy the context.
      
      Rather than calling fs_type->mount(), an fs_context struct is created and
      fs_type->init_fs_context() is called to set it up.  Pointers exist for the
      filesystem and LSM to hang their private data off.
      
      A set of operations has to be set by ->init_fs_context() to provide
      freeing, duplication, option parsing, binary data parsing, validation,
      mounting and superblock filling.
      
      Legacy filesystems are supported by the provision of a set of legacy
      fs_context operations that build up a list of mount options and then invoke
      fs_type->mount() from within the fs_context ->get_tree() operation.  This
      allows all filesystems to be accessed using fs_context.
      
      It should be noted that, whilst this patch adds a lot of lines of code,
      there is quite a bit of duplication with existing code that can be
      eliminated should all filesystems be converted over.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      3e1aeb00
    • David Howells's avatar
      vfs: Put security flags into the fs_context struct · 846e5662
      David Howells authored
      Put security flags, such as SECURITY_LSM_NATIVE_LABELS, into the filesystem
      context so that the filesystem can communicate them to the LSM more easily.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      846e5662
    • David Howells's avatar
      smack: Implement filesystem context security hooks · 2febd254
      David Howells authored
      Implement filesystem context security hooks for the smack LSM.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      cc: Casey Schaufler <casey@schaufler-ca.com>
      cc: linux-security-module@vger.kernel.org
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      2febd254
    • David Howells's avatar
      selinux: Implement the new mount API LSM hooks · 442155c1
      David Howells authored
      Implement the new mount API LSM hooks for SELinux.  At some point the old
      hooks will need to be removed.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      cc: Paul Moore <paul@paul-moore.com>
      cc: Stephen Smalley <sds@tycho.nsa.gov>
      cc: selinux@tycho.nsa.gov
      cc: linux-security-module@vger.kernel.org
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      442155c1
    • David Howells's avatar
      vfs: Add LSM hooks for the new mount API · da2441fd
      David Howells authored
      Add LSM hooks for use by the new mount API and filesystem context code.
      This includes:
      
       (1) Hooks to handle allocation, duplication and freeing of the security
           record attached to a filesystem context.
      
       (2) A hook to snoop source specifications.  There may be multiple of these
           if the filesystem supports it.  They will to be local files/devices if
           fs_context::source_is_dev is true and will be something else, possibly
           remote server specifications, if false.
      
       (3) A hook to snoop superblock configuration options in key[=val] form.
           If the LSM decides it wants to handle it, it can suppress the option
           being passed to the filesystem.  Note that 'val' may include commas
           and binary data with the fsopen patch.
      
       (4) A hook to perform validation and allocation after the configuration
           has been done but before the superblock is allocated and set up.
      
       (5) A hook to transfer the security from the context to a newly created
           superblock.
      
       (6) A hook to rule on whether a path point can be used as a mountpoint.
      
      These are intended to replace:
      
      	security_sb_copy_data
      	security_sb_kern_mount
      	security_sb_mount
      	security_sb_set_mnt_opts
      	security_sb_clone_mnt_opts
      	security_sb_parse_opts_str
      
      [AV -- some of the methods being replaced are already gone, some of the
      methods are not added for the lack of need]
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      cc: linux-security-module@vger.kernel.org
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      da2441fd
    • David Howells's avatar
      vfs: Add configuration parser helpers · 31d921c7
      David Howells authored
      Because the new API passes in key,value parameters, match_token() cannot be
      used with it.  Instead, provide three new helpers to aid with parsing:
      
       (1) fs_parse().  This takes a parameter and a simple static description of
           all the parameters and maps the key name to an ID.  It returns 1 on a
           match, 0 on no match if unknowns should be ignored and some other
           negative error code on a parse error.
      
           The parameter description includes a list of key names to IDs, desired
           parameter types and a list of enumeration name -> ID mappings.
      
           [!] Note that for the moment I've required that the key->ID mapping
           array is expected to be sorted and unterminated.  The size of the
           array is noted in the fsconfig_parser struct.  This allows me to use
           bsearch(), but I'm not sure any performance gain is worth the hassle
           of requiring people to keep the array sorted.
      
           The parameter type array is sized according to the number of parameter
           IDs and is indexed directly.  The optional enum mapping array is an
           unterminated, unsorted list and the size goes into the fsconfig_parser
           struct.
      
           The function can do some additional things:
      
      	(a) If it's not ambiguous and no value is given, the prefix "no" on
      	    a key name is permitted to indicate that the parameter should
      	    be considered negatory.
      
      	(b) If the desired type is a single simple integer, it will perform
      	    an appropriate conversion and store the result in a union in
      	    the parse result.
      
      	(c) If the desired type is an enumeration, {key ID, name} will be
      	    looked up in the enumeration list and the matching value will
      	    be stored in the parse result union.
      
      	(d) Optionally generate an error if the key is unrecognised.
      
           This is called something like:
      
      	enum rdt_param {
      		Opt_cdp,
      		Opt_cdpl2,
      		Opt_mba_mpbs,
      		nr__rdt_params
      	};
      
      	const struct fs_parameter_spec rdt_param_specs[nr__rdt_params] = {
      		[Opt_cdp]	= { fs_param_is_bool },
      		[Opt_cdpl2]	= { fs_param_is_bool },
      		[Opt_mba_mpbs]	= { fs_param_is_bool },
      	};
      
      	const const char *const rdt_param_keys[nr__rdt_params] = {
      		[Opt_cdp]	= "cdp",
      		[Opt_cdpl2]	= "cdpl2",
      		[Opt_mba_mpbs]	= "mba_mbps",
      	};
      
      	const struct fs_parameter_description rdt_parser = {
      		.name		= "rdt",
      		.nr_params	= nr__rdt_params,
      		.keys		= rdt_param_keys,
      		.specs		= rdt_param_specs,
      		.no_source	= true,
      	};
      
      	int rdt_parse_param(struct fs_context *fc,
      			    struct fs_parameter *param)
      	{
      		struct fs_parse_result parse;
      		struct rdt_fs_context *ctx = rdt_fc2context(fc);
      		int ret;
      
      		ret = fs_parse(fc, &rdt_parser, param, &parse);
      		if (ret < 0)
      			return ret;
      
      		switch (parse.key) {
      		case Opt_cdp:
      			ctx->enable_cdpl3 = true;
      			return 0;
      		case Opt_cdpl2:
      			ctx->enable_cdpl2 = true;
      			return 0;
      		case Opt_mba_mpbs:
      			ctx->enable_mba_mbps = true;
      			return 0;
      		}
      
      		return -EINVAL;
      	}
      
       (2) fs_lookup_param().  This takes a { dirfd, path, LOOKUP_EMPTY? } or
           string value and performs an appropriate path lookup to convert it
           into a path object, which it will then return.
      
           If the desired type was a blockdev, the type of the looked up inode
           will be checked to make sure it is one.
      
           This can be used like:
      
      	enum foo_param {
      		Opt_source,
      		nr__foo_params
      	};
      
      	const struct fs_parameter_spec foo_param_specs[nr__foo_params] = {
      		[Opt_source]	= { fs_param_is_blockdev },
      	};
      
      	const char *char foo_param_keys[nr__foo_params] = {
      		[Opt_source]	= "source",
      	};
      
      	const struct constant_table foo_param_alt_keys[] = {
      		{ "device",	Opt_source },
      	};
      
      	const struct fs_parameter_description foo_parser = {
      		.name		= "foo",
      		.nr_params	= nr__foo_params,
      		.nr_alt_keys	= ARRAY_SIZE(foo_param_alt_keys),
      		.keys		= foo_param_keys,
      		.alt_keys	= foo_param_alt_keys,
      		.specs		= foo_param_specs,
      	};
      
      	int foo_parse_param(struct fs_context *fc,
      			    struct fs_parameter *param)
      	{
      		struct fs_parse_result parse;
      		struct foo_fs_context *ctx = foo_fc2context(fc);
      		int ret;
      
      		ret = fs_parse(fc, &foo_parser, param, &parse);
      		if (ret < 0)
      			return ret;
      
      		switch (parse.key) {
      		case Opt_source:
      			return fs_lookup_param(fc, &foo_parser, param,
      					       &parse, &ctx->source);
      		default:
      			return -EINVAL;
      		}
      	}
      
       (3) lookup_constant().  This takes a table of named constants and looks up
           the given name within it.  The table is expected to be sorted such
           that bsearch() be used upon it.
      
           Possibly I should require the table be terminated and just use a
           for-loop to scan it instead of using bsearch() to reduce hassle.
      
           Tables look something like:
      
      	static const struct constant_table bool_names[] = {
      		{ "0",		false },
      		{ "1",		true },
      		{ "false",	false },
      		{ "no",		false },
      		{ "true",	true },
      		{ "yes",	true },
      	};
      
           and a lookup is done with something like:
      
      	b = lookup_constant(bool_names, param->string, -1);
      
      Additionally, optional validation routines for the parameter description
      are provided that can be enabled at compile time.  A later patch will
      invoke these when a filesystem is registered.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      31d921c7
  2. 30 Jan, 2019 11 commits
    • David Howells's avatar
      vfs: Introduce logging functions · c6b82263
      David Howells authored
      Introduce a set of logging functions through which informational messages,
      warnings and error messages incurred by the mount procedure can be logged
      and, in a future patch, passed to userspace instead by way of the
      filesystem configuration context file descriptor.
      
      There are four functions:
      
       (1) infof(const char *fmt, ...);
      
           Logs an informational message.
      
       (2) warnf(const char *fmt, ...);
      
           Logs a warning message.
      
       (3) errorf(const char *fmt, ...);
      
           Logs an error message.
      
       (4) invalf(const char *fmt, ...);
      
           As errof(), but returns -EINVAL so can be used on a return statement.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      c6b82263
    • Al Viro's avatar
      introduce fs_context methods · f3a09c92
      Al Viro authored
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      f3a09c92
    • Al Viro's avatar
      fs_context flavour for submounts · e1a91586
      Al Viro authored
      This is an eventual replacement for vfs_submount() uses.  Unlike the
      "mount" and "remount" cases, the users of that thing are not in VFS -
      they are buried in various ->d_automount() instances and rather than
      converting them all at once we introduce the (thankfully small and
      simple) infrastructure here and deal with the prospective users in
      afs, nfs, etc. parts of the series.
      
      Here we just introduce a new constructor (fs_context_for_submount())
      along with the corresponding enum constant to be put into fc->purpose
      for those.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      e1a91586
    • David Howells's avatar
      convert do_remount_sb() to fs_context · 8d0347f6
      David Howells authored
      Replace do_remount_sb() with a function, reconfigure_super(), that's
      fs_context aware.  The fs_context is expected to be parameterised already
      and have ->root pointing to the superblock to be reconfigured.
      
      A legacy wrapper is provided that is intended to be called from the
      fs_context ops when those appear, but for now is called directly from
      reconfigure_super().  This wrapper invokes the ->remount_fs() superblock op
      for the moment.  It is intended that the remount_fs() op will be phased
      out.
      
      The fs_context->purpose is set to FS_CONTEXT_FOR_RECONFIGURE to indicate
      that the context is being used for reconfiguration.
      
      do_umount_root() is provided to consolidate remount-to-R/O for umount and
      emergency remount by creating a context and invoking reconfiguration.
      
      do_remount(), do_umount() and do_emergency_remount_callback() are switched
      to use the new process.
      
      [AV -- fold UMOUNT and EMERGENCY_REMOUNT in; fixes the
      umount / bug, gets rid of pointless complexity]
      [AV -- set ->net_ns in all cases; nfs remount will need that]
      [AV -- shift security_sb_remount() call into reconfigure_super(); the callers
      that didn't do security_sb_remount() have NULL fc->security anyway, so it's
      a no-op for them]
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Co-developed-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      8d0347f6
    • Al Viro's avatar
      vfs_get_tree(): evict the call of security_sb_kern_mount() · c9ce29ed
      Al Viro authored
      Right now vfs_get_tree() calls security_sb_kern_mount() (i.e.
      mount MAC) unless it gets MS_KERNMOUNT or MS_SUBMOUNT in flags.
      Doing it that way is both clumsy and imprecise.
      
      Consider the callers' tree of vfs_get_tree():
      vfs_get_tree()
              <- do_new_mount()
      	<- vfs_kern_mount()
      		<- simple_pin_fs()
      		<- vfs_submount()
      		<- kern_mount_data()
      		<- init_mount_tree()
      		<- btrfs_mount()
      			<- vfs_get_tree()
      		<- nfs_do_root_mount()
      			<- nfs4_try_mount()
      				<- nfs_fs_mount()
      					<- vfs_get_tree()
      			<- nfs4_referral_mount()
      
      do_new_mount() always does need MAC (we are guaranteed that neither
      MS_KERNMOUNT nor MS_SUBMOUNT will be passed there).
      
      simple_pin_fs(), vfs_submount() and kern_mount_data() pass explicit
      flags inhibiting that check.  So does nfs4_referral_mount() (the
      flags there are ulimately coming from vfs_submount()).
      
      init_mount_tree() is called too early for anything LSM-related; it
      doesn't matter whether we attempt those checks, they'll do nothing.
      
      Finally, in case of btrfs_mount() and nfs_fs_mount(), doing MAC
      is pointless - either the caller will do it, or the flags are
      such that we wouldn't have done it either.
      
      In other words, the one and only case when we want that check
      done is when we are called from do_new_mount(), and there we
      want it unconditionally.
      
      So let's simply move it there.  The superblock is still locked,
      so nobody is going to get access to it (via ustat(2), etc.)
      until we get a chance to apply the checks - we are free to
      move them to any point up to where we drop ->s_umount (in
      do_new_mount_fc()).
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      c9ce29ed
    • David Howells's avatar
      new helper: do_new_mount_fc() · 132e4608
      David Howells authored
      Create an fs_context-aware version of do_new_mount().  This takes an
      fs_context with a superblock already attached to it.
      
      Make do_new_mount() use do_new_mount_fc() rather than do_new_mount(); this
      allows the consolidation of the mount creation, check and add steps.
      
      To make this work, mount_too_revealing() is changed to take a superblock
      rather than a mount (which the fs_context doesn't have available), allowing
      this check to be done before the mount object is created.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Co-developed-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      132e4608
    • Al Viro's avatar
      teach vfs_get_tree() to handle subtype, switch do_new_mount() to it · a0c9a8b8
      Al Viro authored
      Roll the handling of subtypes into do_new_mount() and vfs_get_tree().  The
      former determines any subtype string and hangs it off the fs_context; the
      latter applies it.
      
      Make do_new_mount() create, parameterise and commit an fs_context and
      create a mount for itself rather than calling vfs_kern_mount().
      
      [AV -- missing kstrdup()]
      [AV -- ... and no kstrdup() if we get to setting ->s_submount - we
      simply transfer it from fc, leaving NULL behind]
      [AV -- constify ->s_submount, while we are at it]
      Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      a0c9a8b8
    • Al Viro's avatar
      new helpers: vfs_create_mount(), fc_mount() · 8f291889
      Al Viro authored
      Create a new helper, vfs_create_mount(), that creates a detached vfsmount
      object from an fs_context that has a superblock attached to it.
      
      Almost all uses will be paired with immediately preceding vfs_get_tree();
      add a helper for such combination.
      
      Switch vfs_kern_mount() to use this.
      
      NOTE: mild behaviour change; passing NULL as 'device name' to
      something like procfs will change /proc/*/mountstats - "device none"
      instead on "no device".  That is consistent with /proc/mounts et.al.
      
      [do'h - EXPORT_SYMBOL_GPL slipped in by mistake; removed]
      [AV -- remove confused comment from vfs_create_mount()]
      [AV -- removed the second argument]
      Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      8f291889
    • David Howells's avatar
      vfs: Introduce fs_context, switch vfs_kern_mount() to it. · 9bc61ab1
      David Howells authored
      Introduce a filesystem context concept to be used during superblock
      creation for mount and superblock reconfiguration for remount.  This is
      allocated at the beginning of the mount procedure and into it is placed:
      
       (1) Filesystem type.
      
       (2) Namespaces.
      
       (3) Source/Device names (there may be multiple).
      
       (4) Superblock flags (SB_*).
      
       (5) Security details.
      
       (6) Filesystem-specific data, as set by the mount options.
      
      Accessor functions are then provided to set up a context, parameterise it
      from monolithic mount data (the data page passed to mount(2)) and tear it
      down again.
      
      A legacy wrapper is provided that implements what will be the basic
      operations, wrapping access to filesystems that aren't yet aware of the
      fs_context.
      
      Finally, vfs_kern_mount() is changed to make use of the fs_context and
      mount_fs() is replaced by vfs_get_tree(), called from vfs_kern_mount().
      [AV -- add missing kstrdup()]
      [AV -- put_cred() can be unconditional - fc->cred can't be NULL]
      [AV -- take legacy_validate() contents into legacy_parse_monolithic()]
      [AV -- merge KERNEL_MOUNT and USER_MOUNT]
      [AV -- don't unlock superblock on success return from vfs_get_tree()]
      [AV -- kill 'reference' argument of init_fs_context()]
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Co-developed-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      9bc61ab1
    • Al Viro's avatar
      saner handling of temporary namespaces · 74e83122
      Al Viro authored
      mount_subtree() creates (and soon destroys) a temporary namespace,
      so that automounts could function normally.  These beasts should
      never become anyone's current namespaces; they don't, but it would
      be better to make prevention of that more straightforward.  And
      since they don't become anyone's current namespace, we don't need
      to bother with reserving procfs inums for those.
      
      Teach alloc_mnt_ns() to skip inum allocation if told so, adjust
      put_mnt_ns() accordingly, make mount_subtree() use temporary
      (anon) namespace.  is_anon_ns() checks if a namespace is such.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      74e83122
    • Al Viro's avatar
      separate copying and locking mount tree on cross-userns copies · 3bd045cc
      Al Viro authored
      Rather than having propagate_mnt() check doing unprivileged copies,
      lock them before commit_tree().
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      3bd045cc
  3. 17 Jan, 2019 3 commits
    • Al Viro's avatar
      kill kernfs_pin_sb() · 6d7fbce7
      Al Viro authored
      unused now and impossible to use safely anyway.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      6d7fbce7
    • Al Viro's avatar
      cgroup: saner refcounting for cgroup_root · 35ac1184
      Al Viro authored
      * make the reference from superblock to cgroup_root counting -
      do cgroup_put() in cgroup_kill_sb() whether we'd done
      percpu_ref_kill() or not; matching grab is done when we allocate
      a new root.  That gives the same refcounting rules for all callers
      of cgroup_do_mount() - a reference to cgroup_root has been grabbed
      by caller and it either is transferred to new superblock or dropped.
      
      * have cgroup_kill_sb() treat an already killed refcount as "just
      don't bother killing it, then".
      
      * after successful cgroup_do_mount() have cgroup1_mount() recheck
      if we'd raced with mount/umount from somebody else and cgroup_root
      got killed.  In that case we drop the superblock and bugger off
      with -ERESTARTSYS, same as if we'd found it in the list already
      dying.
      
      * don't bother with delayed initialization of refcount - it's
      unreliable and not needed.  No need to prevent attempts to bump
      the refcount if we find cgroup_root of another mount in progress -
      sget will reuse an existing superblock just fine and if the
      other sb manages to die before we get there, we'll catch
      that immediately after cgroup_do_mount().
      
      * don't bother with kernfs_pin_sb() - no need for doing that
      either.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      35ac1184
    • Al Viro's avatar
      fix cgroup_do_mount() handling of failure exits · 399504e2
      Al Viro authored
      same story as with last May fixes in sysfs (7b745a4e
      "unfuck sysfs_mount()"); new_sb is left uninitialized
      in case of early errors in kernfs_mount_ns() and papering
      over it by treating any error from kernfs_mount_ns() as
      equivalent to !new_ns ends up conflating the cases when
      objects had never been transferred to a superblock with
      ones when that has happened and resulting new superblock
      had been dropped.  Easily fixed (same way as in sysfs
      case).  Additionally, there's a superblock leak on
      kernfs_node_dentry() failure *and* a dentry leak inside
      kernfs_node_dentry() itself - the latter on probably
      impossible errors, but the former not impossible to trigger
      (as the matter of fact, injecting allocation failures
      at that point *does* trigger it).
      
      Cc: stable@kernel.org
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      399504e2
  4. 13 Jan, 2019 12 commits
    • Linus Torvalds's avatar
      Linux 5.0-rc2 · 1c7fc5cb
      Linus Torvalds authored
      1c7fc5cb
    • Jonathan Neuschäfer's avatar
      kernel/sys.c: Clarify that UNAME26 does not generate unique versions anymore · b7285b42
      Jonathan Neuschäfer authored
      UNAME26 is a mechanism to report Linux's version as 2.6.x, for
      compatibility with old/broken software.  Due to the way it is
      implemented, it would have to be updated after 5.0, to keep the
      resulting versions unique.  Linus Torvalds argued:
      
       "Do we actually need this?
      
        I'd rather let it bitrot, and just let it return random versions. It
        will just start again at 2.4.60, won't it?
      
        Anybody who uses UNAME26 for a 5.x kernel might as well think it's
        still 4.x. The user space is so old that it can't possibly care about
        differences between 4.x and 5.x, can it?
      
        The only thing that matters is that it shows "2.4.<largeenough>",
        which it will do regardless"
      Signed-off-by: default avatarJonathan Neuschäfer <j.neuschaefer@gmx.net>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b7285b42
    • Linus Torvalds's avatar
      Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc · dbc3c09b
      Linus Torvalds authored
      Pull ARM SoC fixes from Olof Johansson:
       "A bigger batch than I anticipated this week, for two reasons:
      
         - Some fallout on Davinci from board file -> DTB conversion, that
           also includes a few longer-standing fixes (i.e. not recent
           regressions).
      
         - drivers/reset material that has been in linux-next for a while, but
           didn't get sent to us until now for a variety of reasons
           (maintainer out sick, holidays, etc). There's a functional
           dependency in there such that one platform (Altera's SoCFPGA) won't
           boot without one of the patches; instead of reverting the patch
           that got merged, I looked at this set and decided it was small
           enough that I'll pick it up anyway. If you disagree I can revisit
           with a smaller set.
      
        That being said, there's also a handful of the usual stuff:
      
         - Fix for a crash on Armada 7K/8K when the kernel touches
           PSCI-reserved memory
      
         - Fix for PCIe reset on Macchiatobin (Armada 8K development board,
           what this email is sent from in fact :)
      
         - Enable a few new-merged modules for Amlogic in arm64 defconfig
      
         - Error path fixes on Integrator
      
         - Build fix for Renesas and Qualcomm
      
         - Initialization fix for Renesas RZ/G2E
      
        .. plus a few more fixlets"
      
      * tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (28 commits)
        ARM: integrator: impd1: use struct_size() in devm_kzalloc()
        qcom-scm: Include <linux/err.h> header
        gpio: pl061: handle failed allocations
        ARM: dts: kirkwood: Fix polarity of GPIO fan lines
        arm64: dts: marvell: mcbin: fix PCIe reset signal
        arm64: dts: marvell: armada-ap806: reserve PSCI area
        ARM: dts: da850-lcdk: Correct the sound card name
        ARM: dts: da850-lcdk: Correct the audio codec regulators
        ARM: dts: da850-evm: Correct the sound card name
        ARM: dts: da850-evm: Correct the audio codec regulators
        ARM: davinci: omapl138-hawk: fix label names in GPIO lookup entries
        ARM: davinci: dm644x-evm: fix label names in GPIO lookup entries
        ARM: davinci: dm355-evm: fix label names in GPIO lookup entries
        ARM: davinci: da850-evm: fix label names in GPIO lookup entries
        ARM: davinci: da830-evm: fix label names in GPIO lookup entries
        arm64: defconfig: enable modules for amlogic s400 sound card
        reset: uniphier-glue: Add AHCI reset control support in glue layer
        dt-bindings: reset: uniphier: Add AHCI core reset description
        reset: uniphier-usb3: Rename to reset-uniphier-glue
        dt-bindings: reset: uniphier: Replace the expression of USB3 with generic peripherals
        ...
      dbc3c09b
    • Linus Torvalds's avatar
      Merge tag 'for-5.0-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux · 6b529fb0
      Linus Torvalds authored
      Pull btrfs fixes from David Sterba:
      
       - two regression fixes in clone/dedupe ioctls, the generic check
         callback needs to lock extents properly and wait for io to avoid
         problems with writeback and relocation
      
       - fix deadlock when using free space tree due to block group creation
      
       - a recently added check refuses a valid fileystem with seeding device,
         make that work again with a quickfix, proper solution needs more
         intrusive changes
      
      * tag 'for-5.0-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
        btrfs: Use real device structure to verify dev extent
        Btrfs: fix deadlock when using free space tree due to block group creation
        Btrfs: fix race between reflink/dedupe and relocation
        Btrfs: fix race between cloning range ending at eof and writeback
      6b529fb0
    • Linus Torvalds's avatar
      Merge tag 'driver-core-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core · 72d657dd
      Linus Torvalds authored
      Pull driver core fixes from Greg KH:
       "Here is one small sysfs change, and a documentation update for 5.0-rc2
      
        The sysfs change moves from using BUG_ON to WARN_ON, as discussed in
        an email thread on lkml while trying to track down another driver bug.
        sysfs should not be crashing and preventing people from seeing where
        they went wrong. Now it properly recovers and warns the developer.
      
        The documentation update removes the use of BUS_ATTR() as the kernel
        is moving away from this to use the specific BUS_ATTR_RW() and friends
        instead. There are pending patches in all of the different subsystems
        to remove the last users of this macro, but for now, don't advertise
        it should be used anymore to keep new ones from being introduced.
      
        Both have been in linux-next with no reported issues"
      
      * tag 'driver-core-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
        Documentation: driver core: remove use of BUS_ATTR
        sysfs: convert BUG_ON to WARN_ON
      72d657dd
    • Linus Torvalds's avatar
      Merge tag 'staging-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging · f7c1038b
      Linus Torvalds authored
      Pull staging driver fixes from Greg KH:
       "Here are some small staging driver fixes for some reported issues.
      
        One reverts a patch that was made to the rtl8723bs driver that turned
        out to not be needed at all as it was a bug in clang. The others fix
        up some reported issues in the rtl8188eu driver and update the
        MAINTAINERS file to point to Larry for this driver so he can get the
        bug reports easier.
      
        All have been in linux-next with no reported issues"
      
      * tag 'staging-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
        Revert "staging: rtl8723bs: Mark ACPI table declaration as used"
        staging: rtl8188eu: Fix module loading from tasklet for WEP encryption
        staging: rtl8188eu: Fix module loading from tasklet for CCMP encryption
        MAINTAINERS: Add entry for staging driver r8188eu
      f7c1038b
    • Linus Torvalds's avatar
      Merge tag 'tty-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty · 437e878a
      Linus Torvalds authored
      Pull tty/serial fixes from Greg KH:
       "Here are 2 tty and serial fixes for 5.0-rc2 that resolve some reported
        issues.
      
        The first is a simple serial driver fix for a regression that showed
        up in 5.0-rc1. The second one resolves a number of reported issues
        with the recent tty locking fixes that went into 5.0-rc1. Lots of
        people have tested the second one and say it resolves their issues.
      
        Both have been in linux-next with no reported issues"
      
      * tag 'tty-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
        tty: Don't hold ldisc lock in tty_reopen() if ldisc present
        serial: lantiq: Do not swap register read/writes
      437e878a
    • Linus Torvalds's avatar
      Merge tag 'usb-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb · 1dd8a3f6
      Linus Torvalds authored
      Pull USB fixes from Greg KH:
       "Here are some small USB driver fixes and quirk updates for 5.0-rc2.
      
        The majority here are some quirks for some storage devices to get them
        to work properly. There's also a fix here to resolve the reported
        issues with some audio devices that say they are UAC3 compliant, but
        really are not.
      
        And a fix up for the MAINTAINERS file to remove a dead url.
      
        All have been in linux-next with no reported issues"
      
      * tag 'usb-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
        usb: storage: Remove outdated URL from MAINTAINERS
        USB: Add USB_QUIRK_DELAY_CTRL_MSG quirk for Corsair K70 RGB
        usbcore: Select only first configuration for non-UAC3 compliant devices
        USB: storage: add quirk for SMI SM3350
        USB: storage: don't insert sane sense for SPC3+ when bad sense specified
        usb: cdc-acm: send ZLP for Telit 3G Intel based modems
      1dd8a3f6
    • Linus Torvalds's avatar
      Merge tag '5.0-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6 · 0f9d140a
      Linus Torvalds authored
      Pull cifs fixes from Steve French:
       "A set of cifs/smb3 fixes, 4 for stable, most from Pavel. His patches
        fix an important set of crediting (flow control) problems, and also
        two problems in cifs_writepages, ddressing some large i/o and also
        compounding issues"
      
      * tag '5.0-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
        cifs: update internal module version number
        CIFS: Fix error paths in writeback code
        CIFS: Move credit processing to mid callbacks for SMB3
        CIFS: Fix credits calculation for cancelled requests
        cifs: Fix potential OOB access of lock element array
        cifs: Limit memory used by lock request calls to a page
        cifs: move large array from stack to heap
        CIFS: Do not hide EINTR after sending network packets
        CIFS: Fix credit computation for compounded requests
        CIFS: Do not set credits to 1 if the server didn't grant anything
        CIFS: Fix adjustment of credits for MTU requests
        cifs: Fix a tiny potential memory leak
        cifs: Fix a debug message
      0f9d140a
    • Olof Johansson's avatar
      Merge tag 'reset-for-5.0-rc2' of git://git.pengutronix.de/git/pza/linux into fixes · 46561217
      Olof Johansson authored
      Late reset controller changes for v5.0
      
      This adds missing deassert functionality to the ARC HSDK reset driver,
      fixes some indentation and grammar issues in the kernel docs, adds a
      helper to count the number of resets on a device for the non-DT case
      as well, adds an early reset driver for SoCFPGA and simple reset driver
      support for Stratix10, and generalizes the uniphier USB3 glue layer
      reset to also cover AHCI.
      
      * tag 'reset-for-5.0-rc2' of git://git.pengutronix.de/git/pza/linux:
        reset: uniphier-glue: Add AHCI reset control support in glue layer
        dt-bindings: reset: uniphier: Add AHCI core reset description
        reset: uniphier-usb3: Rename to reset-uniphier-glue
        dt-bindings: reset: uniphier: Replace the expression of USB3 with generic peripherals
        ARM: socfpga: dts: document "altr,stratix10-rst-mgr" binding
        reset: socfpga: add an early reset driver for SoCFPGA
        reset: fix null pointer dereference on dev by dev_name
        reset: Add reset_control_get_count()
        reset: Improve reset controller kernel docs
        ARC: HSDK: improve reset driver
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      46561217
    • Olof Johansson's avatar
      Merge tag 'mvebu-fixes-5.0-1' of git://git.infradead.org/linux-mvebu into fixes · 56acb3ef
      Olof Johansson authored
      mvebu fixes for 5.0
      
      They are all device tree fixes which also worth being in stable:
      
       - Reserve PSCI area on Armada 7K/8K preventing the kernel accessing
         this area and crashing while doing it.
      
       - Use correct PCIe reset signal on MACCHIATOBin  (Armada 8040 based)
      
       - Fix polarity of GPIO fan line D-Link DNS NASes(kikwood based)
      
      * tag 'mvebu-fixes-5.0-1' of git://git.infradead.org/linux-mvebu:
        ARM: dts: kirkwood: Fix polarity of GPIO fan lines
        arm64: dts: marvell: mcbin: fix PCIe reset signal
        arm64: dts: marvell: armada-ap806: reserve PSCI area
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      56acb3ef
    • Olof Johansson's avatar
      Merge tag 'integrator-fixes-armsoc' of... · 2ec472ed
      Olof Johansson authored
      Merge tag 'integrator-fixes-armsoc' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator into fixes
      
      Fixes for the Integrator:
      - Handle failed allocations in the IM/PC bus attachment.
      - Use struct_size() for allocation.
      
      * tag 'integrator-fixes-armsoc' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator:
        ARM: integrator: impd1: use struct_size() in devm_kzalloc()
        gpio: pl061: handle failed allocations
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      2ec472ed