17 Jul, 2017

1 commit

  • Firstly by applying the following with coccinelle's spatch:

    @@ expression SB; @@
    -SB->s_flags & MS_RDONLY
    +sb_rdonly(SB)

    to effect the conversion to sb_rdonly(sb), then by applying:

    @@ expression A, SB; @@
    (
    -(!sb_rdonly(SB)) && A
    +!sb_rdonly(SB) && A
    |
    -A != (sb_rdonly(SB))
    +A != sb_rdonly(SB)
    |
    -A == (sb_rdonly(SB))
    +A == sb_rdonly(SB)
    |
    -!(sb_rdonly(SB))
    +!sb_rdonly(SB)
    |
    -A && (sb_rdonly(SB))
    +A && sb_rdonly(SB)
    |
    -A || (sb_rdonly(SB))
    +A || sb_rdonly(SB)
    |
    -(sb_rdonly(SB)) != A
    +sb_rdonly(SB) != A
    |
    -(sb_rdonly(SB)) == A
    +sb_rdonly(SB) == A
    |
    -(sb_rdonly(SB)) && A
    +sb_rdonly(SB) && A
    |
    -(sb_rdonly(SB)) || A
    +sb_rdonly(SB) || A
    )

    @@ expression A, B, SB; @@
    (
    -(sb_rdonly(SB)) ? 1 : 0
    +sb_rdonly(SB)
    |
    -(sb_rdonly(SB)) ? A : B
    +sb_rdonly(SB) ? A : B
    )

    to remove left over excess bracketage and finally by applying:

    @@ expression A, SB; @@
    (
    -(A & MS_RDONLY) != sb_rdonly(SB)
    +(bool)(A & MS_RDONLY) != sb_rdonly(SB)
    |
    -(A & MS_RDONLY) == sb_rdonly(SB)
    +(bool)(A & MS_RDONLY) == sb_rdonly(SB)
    )

    to make comparisons against the result of sb_rdonly() (which is a bool)
    work correctly.

    Signed-off-by: David Howells

    David Howells
     

30 Sep, 2013

1 commit


13 Mar, 2013

1 commit

  • I had assumed that the only use of module aliases for filesystems
    prior to "fs: Limit sys_mount to only request filesystem modules."
    was in request_module. It turns out I was wrong. At least mkinitcpio
    in Arch linux uses these aliases.

    So readd the preexising aliases, to keep from breaking userspace.

    Userspace eventually will have to follow and use the same aliases the
    kernel does. So at some point we may be delete these aliases without
    problems. However that day is not today.

    Signed-off-by: "Eric W. Biederman"

    Eric W. Biederman
     

04 Mar, 2013

1 commit

  • 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
    Acked-by: Kees Cook
    Reported-by: Kees Cook
    Signed-off-by: "Eric W. Biederman"

    Eric W. Biederman
     

10 Oct, 2012

1 commit


21 Mar, 2012

2 commits


13 Jan, 2011

1 commit


07 Jan, 2011

1 commit

  • Reduce some branches and memory accesses in dcache lookup by adding dentry
    flags to indicate common d_ops are set, rather than having to check them.
    This saves a pointer memory access (dentry->d_op) in common path lookup
    situations, and saves another pointer load and branch in cases where we
    have d_op but not the particular operation.

    Patched with:

    git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i

    Signed-off-by: Nick Piggin

    Nick Piggin
     

29 Oct, 2010

1 commit


11 Aug, 2010

3 commits

  • This adds byte order autodetection (of PDP-11 and LE filesystems). No
    attempt is made to detect big-endian filesystems -- were there any?
    Tested with PDP-11 v7 filesystems and PC-IX maintenance floppy.

    [akpm@linux-foundation.org: coding-style fixes]
    [AV: parser.h inclusion was a rudiment of discarded stuff]
    Signed-off-by: Lubomir Rintel
    Cc: Christoph Hellwig
    Cc: Al Viro
    Signed-off-by: Andrew Morton
    Signed-off-by: Al Viro

    Lubomir Rintel
     
  • Newly mkfs-ed filesystems from Seventh Edition have last modification
    time set to zero, but are otherwise perfectly valid.

    Also, tighten up other sanity checks to filter out most filesystems with
    different bytesex than we're using.

    Cc: Christoph Hellwig
    Signed-off-by: Lubomir Rintel
    Signed-off-by: Al Viro

    Lubomir Rintel
     
  • So that the module gets autoloaded when a v7 filesystem is mounted.

    Cc: Christoph Hellwig
    Signed-off-by: Lubomir Rintel
    Signed-off-by: Al Viro

    Lubomir Rintel
     

10 Aug, 2010

1 commit


08 Feb, 2008

1 commit

  • Stop the SYSV filesystem from using iget() and read_inode(). Replace
    sysv_read_inode() with sysv_iget(), and call that instead of iget().
    sysv_iget() then uses iget_locked() directly and returns a proper error code
    instead of an inode in the event of an error.

    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: David Howells
    Acked-by: Christoph Hellwig
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Howells
     

23 Dec, 2006

1 commit


12 Oct, 2006

1 commit


27 Sep, 2006

1 commit


23 Jun, 2006

1 commit

  • Extend the get_sb() filesystem operation to take an extra argument that
    permits the VFS to pass in the target vfsmount that defines the mountpoint.

    The filesystem is then required to manually set the superblock and root dentry
    pointers. For most filesystems, this should be done with simple_set_mnt()
    which will set the superblock pointer and then set the root dentry to the
    superblock's s_root (as per the old default behaviour).

    The get_sb() op now returns an integer as there's now no need to return the
    superblock pointer.

    This patch permits a superblock to be implicitly shared amongst several mount
    points, such as can be done with NFS to avoid potential inode aliasing. In
    such a case, simple_set_mnt() would not be called, and instead the mnt_root
    and mnt_sb would be set directly.

    The patch also makes the following changes:

    (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount
    pointer argument and return an integer, so most filesystems have to change
    very little.

    (*) If one of the convenience function is not used, then get_sb() should
    normally call simple_set_mnt() to instantiate the vfsmount. This will
    always return 0, and so can be tail-called from get_sb().

    (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the
    dcache upon superblock destruction rather than shrink_dcache_anon().

    This is required because the superblock may now have multiple trees that
    aren't actually bound to s_root, but that still need to be cleaned up. The
    currently called functions assume that the whole tree is rooted at s_root,
    and that anonymous dentries are not the roots of trees which results in
    dentries being left unculled.

    However, with the way NFS superblock sharing are currently set to be
    implemented, these assumptions are violated: the root of the filesystem is
    simply a dummy dentry and inode (the real inode for '/' may well be
    inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries
    with child trees.

    [*] Anonymous until discovered from another tree.

    (*) The documentation has been adjusted, including the additional bit of
    changing ext2_* into foo_* in the documentation.

    [akpm@osdl.org: convert ipath_fs, do other stuff]
    Signed-off-by: David Howells
    Acked-by: Al Viro
    Cc: Nathan Scott
    Cc: Roland Dreier
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Howells
     

24 Mar, 2006

1 commit

  • Use ARRAY_SIZE macro instead of sizeof(x)/sizeof(x[0]) and remove a
    duplicate of ARRAY_SIZE. Some trailing whitespaces are also deleted.

    Signed-off-by: Tobias Klauser
    Cc: David Howells
    Cc: Dave Kleikamp
    Acked-by: Trond Myklebust
    Cc: Neil Brown
    Cc: Chris Mason
    Cc: Jeff Mahoney
    Cc: Christoph Hellwig
    Cc: Nathan Scott
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Tobias Klauser
     

17 Apr, 2005

1 commit

  • Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds