06 Oct, 2020

1 commit

  • We are generating incorrect path in case of rename retry because
    we are restarting from wrong dentry. We should restart from the
    dentry which was received in the call to nfs_path.

    CC: stable@vger.kernel.org
    Signed-off-by: Ashish Sangwan
    Signed-off-by: Anna Schumaker

    Ashish Sangwan
     

03 Apr, 2020

2 commits


18 Mar, 2020

1 commit


26 Feb, 2020

1 commit


25 Jan, 2020

1 commit


15 Jan, 2020

8 commits

  • 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
    Signed-off-by: Anna Schumaker

    Scott Mayhew
     
  • 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
    Signed-off-by: Anna Schumaker

    Scott Mayhew
     
  • 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
    Signed-off-by: Al Viro
    Signed-off-by: Scott Mayhew
    Signed-off-by: Anna Schumaker

    David Howells
     
  • it's always either nfs_set_sb_security() or nfs_clone_sb_security(),
    the choice being controlled by mount_info->cloned != NULL. No need
    to add methods, especially when both instances live right next to
    the caller and are never accessed anywhere else.

    Reviewed-by: David Howells
    Signed-off-by: Al Viro
    Signed-off-by: Anna Schumaker

    Al Viro
     
  • The only possible values are nfs_fill_super and nfs_clone_super. The
    latter is used only when crossing into a submount and it is almost
    identical to the former; the only differences are
    * ->s_time_gran unconditionally set to 1 (even for v2 mounts).
    Regression dating back to 2012, actually.
    * ->s_blocksize/->s_blocksize_bits set to that of parent.

    Rather than messing with the method, stash ->s_blocksize_bits in
    mount_info in submount case and after the (now unconditional)
    call of nfs_fill_super() override ->s_blocksize/->s_blocksize_bits
    if that has been set.

    Reviewed-by: David Howells
    Signed-off-by: Al Viro
    Signed-off-by: Anna Schumaker

    Al Viro
     
  • they are identical now...

    Reviewed-by: David Howells
    Signed-off-by: Al Viro
    Signed-off-by: Anna Schumaker

    Al Viro
     
  • That will allow to get rid of passing those references around in
    quite a few places. Moreover, that will allow to merge xdev and
    remote file_system_type.

    Reviewed-by: David Howells
    Signed-off-by: Al Viro
    Signed-off-by: Anna Schumaker

    Al Viro
     
  • Do it in nfs_do_submount() instead. As a side benefit, nfs_clone_data
    doesn't need ->fh and ->fattr anymore.

    Reviewed-by: David Howells
    Signed-off-by: Al Viro
    Signed-off-by: Anna Schumaker

    Al Viro
     

04 Nov, 2019

1 commit


21 May, 2019

1 commit

  • Add SPDX license identifiers to all files which:

    - Have no license information of any form

    - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
    initial scan/conversion to ignore the file

    These files fall under the project license, GPL v2 only. The resulting SPDX
    license identifier is:

    GPL-2.0-only

    Signed-off-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Thomas Gleixner
     

21 Feb, 2019

1 commit


29 May, 2017

1 commit

  • When the call to nfs_devname() fails, the error path attempts to retain
    the error via the mnt variable, but this requires a cast across very
    different types (char * to struct vfsmount *), which the upcoming
    structure layout randomization plugin flags as being potentially
    dangerous in the face of randomization. This is a false positive, but
    what this code actually wants to do is retain the error value, so this
    patch explicitly sets it, instead of using what seems to be an
    unexpected cast.

    Signed-off-by: Kees Cook
    Acked-by: Trond Myklebust
    Reviewed-by: Christoph Hellwig

    Kees Cook
     

21 Apr, 2017

1 commit


03 Mar, 2017

1 commit

  • Add a system call to make extended file information available, including
    file creation and some attribute flags where available through the
    underlying filesystem.

    The getattr inode operation is altered to take two additional arguments: a
    u32 request_mask and an unsigned int flags that indicate the
    synchronisation mode. This change is propagated to the vfs_getattr*()
    function.

    Functions like vfs_stat() are now inline wrappers around new functions
    vfs_statx() and vfs_statx_fd() to reduce stack usage.

    ========
    OVERVIEW
    ========

    The idea was initially proposed as a set of xattrs that could be retrieved
    with getxattr(), but the general preference proved to be for a new syscall
    with an extended stat structure.

    A number of requests were gathered for features to be included. The
    following have been included:

    (1) Make the fields a consistent size on all arches and make them large.

    (2) Spare space, request flags and information flags are provided for
    future expansion.

    (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
    __s64).

    (4) Creation time: The SMB protocol carries the creation time, which could
    be exported by Samba, which will in turn help CIFS make use of
    FS-Cache as that can be used for coherency data (stx_btime).

    This is also specified in NFSv4 as a recommended attribute and could
    be exported by NFSD [Steve French].

    (5) Lightweight stat: Ask for just those details of interest, and allow a
    netfs (such as NFS) to approximate anything not of interest, possibly
    without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
    Dilger] (AT_STATX_DONT_SYNC).

    (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
    its cached attributes are up to date [Trond Myklebust]
    (AT_STATX_FORCE_SYNC).

    And the following have been left out for future extension:

    (7) Data version number: Could be used by userspace NFS servers [Aneesh
    Kumar].

    Can also be used to modify fill_post_wcc() in NFSD which retrieves
    i_version directly, but has just called vfs_getattr(). It could get
    it from the kstat struct if it used vfs_xgetattr() instead.

    (There's disagreement on the exact semantics of a single field, since
    not all filesystems do this the same way).

    (8) BSD stat compatibility: Including more fields from the BSD stat such
    as creation time (st_btime) and inode generation number (st_gen)
    [Jeremy Allison, Bernd Schubert].

    (9) Inode generation number: Useful for FUSE and userspace NFS servers
    [Bernd Schubert].

    (This was asked for but later deemed unnecessary with the
    open-by-handle capability available and caused disagreement as to
    whether it's a security hole or not).

    (10) Extra coherency data may be useful in making backups [Andreas Dilger].

    (No particular data were offered, but things like last backup
    timestamp, the data version number and the DOS archive bit would come
    into this category).

    (11) Allow the filesystem to indicate what it can/cannot provide: A
    filesystem can now say it doesn't support a standard stat feature if
    that isn't available, so if, for instance, inode numbers or UIDs don't
    exist or are fabricated locally...

    (This requires a separate system call - I have an fsinfo() call idea
    for this).

    (12) Store a 16-byte volume ID in the superblock that can be returned in
    struct xstat [Steve French].

    (Deferred to fsinfo).

    (13) Include granularity fields in the time data to indicate the
    granularity of each of the times (NFSv4 time_delta) [Steve French].

    (Deferred to fsinfo).

    (14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags.
    Note that the Linux IOC flags are a mess and filesystems such as Ext4
    define flags that aren't in linux/fs.h, so translation in the kernel
    may be a necessity (or, possibly, we provide the filesystem type too).

    (Some attributes are made available in stx_attributes, but the general
    feeling was that the IOC flags were to ext[234]-specific and shouldn't
    be exposed through statx this way).

    (15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
    Michael Kerrisk].

    (Deferred, probably to fsinfo. Finding out if there's an ACL or
    seclabal might require extra filesystem operations).

    (16) Femtosecond-resolution timestamps [Dave Chinner].

    (A __reserved field has been left in the statx_timestamp struct for
    this - if there proves to be a need).

    (17) A set multiple attributes syscall to go with this.

    ===============
    NEW SYSTEM CALL
    ===============

    The new system call is:

    int ret = statx(int dfd,
    const char *filename,
    unsigned int flags,
    unsigned int mask,
    struct statx *buffer);

    The dfd, filename and flags parameters indicate the file to query, in a
    similar way to fstatat(). There is no equivalent of lstat() as that can be
    emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is
    also no equivalent of fstat() as that can be emulated by passing a NULL
    filename to statx() with the fd of interest in dfd.

    Whether or not statx() synchronises the attributes with the backing store
    can be controlled by OR'ing a value into the flags argument (this typically
    only affects network filesystems):

    (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
    respect.

    (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
    its attributes with the server - which might require data writeback to
    occur to get the timestamps correct.

    (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
    network filesystem. The resulting values should be considered
    approximate.

    mask is a bitmask indicating the fields in struct statx that are of
    interest to the caller. The user should set this to STATX_BASIC_STATS to
    get the basic set returned by stat(). It should be noted that asking for
    more information may entail extra I/O operations.

    buffer points to the destination for the data. This must be 256 bytes in
    size.

    ======================
    MAIN ATTRIBUTES RECORD
    ======================

    The following structures are defined in which to return the main attribute
    set:

    struct statx_timestamp {
    __s64 tv_sec;
    __s32 tv_nsec;
    __s32 __reserved;
    };

    struct statx {
    __u32 stx_mask;
    __u32 stx_blksize;
    __u64 stx_attributes;
    __u32 stx_nlink;
    __u32 stx_uid;
    __u32 stx_gid;
    __u16 stx_mode;
    __u16 __spare0[1];
    __u64 stx_ino;
    __u64 stx_size;
    __u64 stx_blocks;
    __u64 __spare1[1];
    struct statx_timestamp stx_atime;
    struct statx_timestamp stx_btime;
    struct statx_timestamp stx_ctime;
    struct statx_timestamp stx_mtime;
    __u32 stx_rdev_major;
    __u32 stx_rdev_minor;
    __u32 stx_dev_major;
    __u32 stx_dev_minor;
    __u64 __spare2[14];
    };

    The defined bits in request_mask and stx_mask are:

    STATX_TYPE Want/got stx_mode & S_IFMT
    STATX_MODE Want/got stx_mode & ~S_IFMT
    STATX_NLINK Want/got stx_nlink
    STATX_UID Want/got stx_uid
    STATX_GID Want/got stx_gid
    STATX_ATIME Want/got stx_atime{,_ns}
    STATX_MTIME Want/got stx_mtime{,_ns}
    STATX_CTIME Want/got stx_ctime{,_ns}
    STATX_INO Want/got stx_ino
    STATX_SIZE Want/got stx_size
    STATX_BLOCKS Want/got stx_blocks
    STATX_BASIC_STATS [The stuff in the normal stat struct]
    STATX_BTIME Want/got stx_btime{,_ns}
    STATX_ALL [All currently available stuff]

    stx_btime is the file creation time, stx_mask is a bitmask indicating the
    data provided and __spares*[] are where as-yet undefined fields can be
    placed.

    Time fields are structures with separate seconds and nanoseconds fields
    plus a reserved field in case we want to add even finer resolution. Note
    that times will be negative if before 1970; in such a case, the nanosecond
    fields will also be negative if not zero.

    The bits defined in the stx_attributes field convey information about a
    file, how it is accessed, where it is and what it does. The following
    attributes map to FS_*_FL flags and are the same numerical value:

    STATX_ATTR_COMPRESSED File is compressed by the fs
    STATX_ATTR_IMMUTABLE File is marked immutable
    STATX_ATTR_APPEND File is append-only
    STATX_ATTR_NODUMP File is not to be dumped
    STATX_ATTR_ENCRYPTED File requires key to decrypt in fs

    Within the kernel, the supported flags are listed by:

    KSTAT_ATTR_FS_IOC_FLAGS

    [Are any other IOC flags of sufficient general interest to be exposed
    through this interface?]

    New flags include:

    STATX_ATTR_AUTOMOUNT Object is an automount trigger

    These are for the use of GUI tools that might want to mark files specially,
    depending on what they are.

    Fields in struct statx come in a number of classes:

    (0) stx_dev_*, stx_blksize.

    These are local system information and are always available.

    (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
    stx_size, stx_blocks.

    These will be returned whether the caller asks for them or not. The
    corresponding bits in stx_mask will be set to indicate whether they
    actually have valid values.

    If the caller didn't ask for them, then they may be approximated. For
    example, NFS won't waste any time updating them from the server,
    unless as a byproduct of updating something requested.

    If the values don't actually exist for the underlying object (such as
    UID or GID on a DOS file), then the bit won't be set in the stx_mask,
    even if the caller asked for the value. In such a case, the returned
    value will be a fabrication.

    Note that there are instances where the type might not be valid, for
    instance Windows reparse points.

    (2) stx_rdev_*.

    This will be set only if stx_mode indicates we're looking at a
    blockdev or a chardev, otherwise will be 0.

    (3) stx_btime.

    Similar to (1), except this will be set to 0 if it doesn't exist.

    =======
    TESTING
    =======

    The following test program can be used to test the statx system call:

    samples/statx/test-statx.c

    Just compile and run, passing it paths to the files you want to examine.
    The file is built automatically if CONFIG_SAMPLES is enabled.

    Here's some example output. Firstly, an NFS directory that crosses to
    another FSID. Note that the AUTOMOUNT attribute is set because transiting
    this directory will cause d_automount to be invoked by the VFS.

    [root@andromeda ~]# /tmp/test-statx -A /warthog/data
    statx(/warthog/data) = 0
    results=7ff
    Size: 4096 Blocks: 8 IO Block: 1048576 directory
    Device: 00:26 Inode: 1703937 Links: 125
    Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
    Access: 2016-11-24 09:02:12.219699527+0000
    Modify: 2016-11-17 10:44:36.225653653+0000
    Change: 2016-11-17 10:44:36.225653653+0000
    Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)

    Secondly, the result of automounting on that directory.

    [root@andromeda ~]# /tmp/test-statx /warthog/data
    statx(/warthog/data) = 0
    results=7ff
    Size: 4096 Blocks: 8 IO Block: 1048576 directory
    Device: 00:27 Inode: 2 Links: 125
    Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
    Access: 2016-11-24 09:02:12.219699527+0000
    Modify: 2016-11-17 10:44:36.225653653+0000
    Change: 2016-11-17 10:44:36.225653653+0000

    Signed-off-by: David Howells
    Signed-off-by: Al Viro

    David Howells
     

01 Feb, 2017

1 commit

  • To support unprivileged users mounting filesystems two permission
    checks have to be performed: a test to see if the user allowed to
    create a mount in the mount namespace, and a test to see if
    the user is allowed to access the specified filesystem.

    The automount case is special in that mounting the original filesystem
    grants permission to mount the sub-filesystems, to any user who
    happens to stumble across the their mountpoint and satisfies the
    ordinary filesystem permission checks.

    Attempting to handle the automount case by using override_creds
    almost works. It preserves the idea that permission to mount
    the original filesystem is permission to mount the sub-filesystem.
    Unfortunately using override_creds messes up the filesystems
    ordinary permission checks.

    Solve this by being explicit that a mount is a submount by introducing
    vfs_submount, and using it where appropriate.

    vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let
    sget and friends know that a mount is a submount so they can take appropriate
    action.

    sget and sget_userns are modified to not perform any permission checks
    on submounts.

    follow_automount is modified to stop using override_creds as that
    has proven problemantic.

    do_mount is modified to always remove the new MS_SUBMOUNT flag so
    that we know userspace will never by able to specify it.

    autofs4 is modified to stop using current_real_cred that was put in
    there to handle the previous version of submount permission checking.

    cifs is modified to pass the mountpoint all of the way down to vfs_submount.

    debugfs is modified to pass the mountpoint all of the way down to
    trace_automount by adding a new parameter. To make this change easier
    a new typedef debugfs_automount_t is introduced to capture the type of
    the debugfs automount function.

    Cc: stable@vger.kernel.org
    Fixes: 069d5ac9ae0d ("autofs: Fix automounts by using current_real_cred()->uid")
    Fixes: aeaa4a79ff6a ("fs: Call d_automount with the filesystems creds")
    Reviewed-by: Trond Myklebust
    Reviewed-by: Seth Forshee
    Signed-off-by: "Eric W. Biederman"

    Eric W. Biederman
     

25 Oct, 2016

1 commit

  • A NFSv4 mount of a subdirectory will show an extra slash (as in
    'server://path') in proc's mountinfo which will not match the device name
    and path. This can cause problems for programs searching for the mount.
    Fix this by checking for a leading slash in the dentry path, if so trim
    away any trailing slashes in the device name.

    Signed-off-by: Benjamin Coddington
    Signed-off-by: Anna Schumaker

    Benjamin Coddington
     

16 Apr, 2015

1 commit


25 Oct, 2013

1 commit


09 Jun, 2013

1 commit

  • After looking at all of the nfsv4 operations the label structure has been added
    to the prototypes of the functions which can transmit label data.

    Signed-off-by: Matthew N. Dodd
    Signed-off-by: Miguel Rodel Felipe
    Signed-off-by: Phua Eu Gene
    Signed-off-by: Khin Mi Mi Aung
    Signed-off-by: Steve Dickson
    Signed-off-by: Trond Myklebust

    David Quigley
     

31 Jan, 2013

1 commit

  • Ensure that any setattr and getattr requests for junctions and/or
    mountpoints are sent to the server. Ever since commit
    0ec26fd0698 (vfs: automount should ignore LOOKUP_FOLLOW), we have
    silently dropped any setattr requests to a server-side mountpoint.
    For referrals, we have silently dropped both getattr and setattr
    requests.

    This patch restores the original behaviour for setattr on mountpoints,
    and tries to do the same for referrals, provided that we have a
    filehandle...

    Signed-off-by: Trond Myklebust
    Cc: stable@vger.kernel.org

    Trond Myklebust
     

01 Nov, 2012

1 commit

  • Since commit c7f404b ('vfs: new superblock methods to override
    /proc/*/mount{s,info}'), nfs_path() is used to generate the mounted
    device name reported back to userland.

    nfs_path() always generates a trailing slash when the given dentry is
    the root of an NFS mount, but userland may expect the original device
    name to be returned verbatim (as it used to be). Make this
    canonicalisation optional and change the callers accordingly.

    [jrnieder@gmail.com: use flag instead of bool argument]
    Reported-and-tested-by: Chris Hiestand
    Reference: http://bugs.debian.org/669314
    Signed-off-by: Ben Hutchings
    Cc: # v2.6.39+
    Signed-off-by: Jonathan Nieder
    Signed-off-by: Trond Myklebust

    Ben Hutchings
     

31 Jul, 2012

3 commits

  • This patch exports symbols needed by the v4 module. In addition, I also
    switch over to using IS_ENABLED() to check if CONFIG_NFS_V4 or
    CONFIG_NFS_V4_MODULE are set.

    The module (nfs4.ko) will be created in the same directory as nfs.ko and
    will be automatically loaded the first time you try to mount over NFS v4.

    Signed-off-by: Bryan Schumaker
    Signed-off-by: Trond Myklebust

    Bryan Schumaker
     
  • The module (nfs2.ko) will be created in the same directory as nfs.ko and
    will be automatically loaded the first time you try to mount over NFS v2.

    Signed-off-by: Bryan Schumaker
    Signed-off-by: Trond Myklebust

    Bryan Schumaker
     
  • I can now share this code with the v2 and v3 code by using the NFS
    subversion structure.

    Signed-off-by: Bryan Schumaker
    Signed-off-by: Trond Myklebust

    Bryan Schumaker
     

28 Apr, 2012

6 commits


17 Feb, 2012

1 commit


13 Jul, 2011

1 commit

  • If the client is using NFS v4.1, then we can use SECINFO_NO_NAME to find
    the secflavor for the initial mount. If the server doesn't support
    SECINFO_NO_NAME then I fall back on the "guess and check" method used
    for v4.0 mounts.

    Signed-off-by: Bryan Schumaker
    Signed-off-by: Trond Myklebust

    Bryan Schumaker
     

13 Apr, 2011

1 commit


07 Apr, 2011

1 commit

  • rpc_authflavor_t is cast from an unsigned int, but the
    initial code tried to use it as a signed int. I fix
    this by passing an rpc_authflavor_t pointer around, and
    returning signed integers from functions.

    Signed-off-by: Bryan Schumaker
    Reported-by: Dan Carpenter
    Signed-off-by: Trond Myklebust

    Bryan Schumaker