25 Oct, 2020

1 commit

  • 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.

    Linus Torvalds
     

17 Oct, 2020

1 commit

  • When use 'stat' tool to display file status, the 'Blocks' field always in
    '0', this is not good for tool 'du'(e.g.: busybox 'du'), it always output
    '0' size for the files under ROMFS since such tool calculates number of
    512B Blocks.

    This patch calculates approx. number of 512B blocks based on inode size.

    Signed-off-by: Libing Zhou
    Signed-off-by: Andrew Morton
    Cc: David Howells
    Cc: Al Viro
    Link: http://lkml.kernel.org/r/20200811052606.4243-1-libing.zhou@nokia-sbell.com
    Signed-off-by: Linus Torvalds

    Libing Zhou
     

19 Sep, 2020

1 commit


20 Sep, 2019

1 commit

  • Pull misc mount API conversions from Al Viro:
    "Conversions to new API for shmem and friends and for mount_mtd()-using
    filesystems.

    As for the rest of the mount API conversions in -next, some of them
    belong in the individual trees (e.g. binderfs one should definitely go
    through android folks, after getting redone on top of their changes).
    I'm going to drop those and send the rest (trivial ones + stuff ACKed
    by maintainers) in a separate series - by that point they are
    independent from each other.

    Some stuff has already migrated into individual trees (NFS conversion,
    for example, or FUSE stuff, etc.); those presumably will go through
    the regular merges from corresponding trees."

    * 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
    vfs: Make fs_parse() handle fs_param_is_fd-type params better
    vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API
    shmem_parse_one(): switch to use of fs_parse()
    shmem_parse_options(): take handling a single option into a helper
    shmem_parse_options(): don't bother with mpol in separate variable
    shmem_parse_options(): use a separate structure to keep the results
    make shmem_fill_super() static
    make ramfs_fill_super() static
    devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()
    vfs: Convert squashfs to use the new mount API
    mtd: Kill mount_mtd()
    vfs: Convert jffs2 to use the new mount API
    vfs: Convert cramfs to use the new mount API
    vfs: Convert romfs to use the new mount API
    vfs: Add a single-or-reconfig keying to vfs_get_super()

    Linus Torvalds
     

06 Sep, 2019

1 commit

  • Convert the romfs filesystem to the new internal mount API as the old
    one will be obsoleted and removed. This allows greater flexibility in
    communication of mount parameters between userspace, the VFS and the
    filesystem.

    See Documentation/filesystems/mount_api.txt for more information.

    Signed-off-by: David Howells
    cc: linux-mtd@lists.infradead.org
    cc: linux-block@vger.kernel.org
    Signed-off-by: Al Viro

    David Howells
     

30 Aug, 2019

1 commit

  • Fill in the appropriate limits to avoid inconsistencies
    in the vfs cached inode times when timestamps are
    outside the permitted range.

    Even though some filesystems are read-only, fill in the
    timestamps to reflect the on-disk representation.

    Signed-off-by: Deepa Dinamani
    Reviewed-by: Darrick J. Wong
    Acked-By: Tigran Aivazian
    Acked-by: Jeff Layton
    Cc: aivazian.tigran@gmail.com
    Cc: al@alarsen.net
    Cc: coda@cs.cmu.edu
    Cc: darrick.wong@oracle.com
    Cc: dushistov@mail.ru
    Cc: dwmw2@infradead.org
    Cc: hch@infradead.org
    Cc: jack@suse.com
    Cc: jaharkes@cs.cmu.edu
    Cc: luisbg@kernel.org
    Cc: nico@fluxnic.net
    Cc: phillip@squashfs.org.uk
    Cc: richard@nod.at
    Cc: salah.triki@gmail.com
    Cc: shaggy@kernel.org
    Cc: linux-xfs@vger.kernel.org
    Cc: codalist@coda.cs.cmu.edu
    Cc: linux-ext4@vger.kernel.org
    Cc: linux-mtd@lists.infradead.org
    Cc: jfs-discussion@lists.sourceforge.net
    Cc: reiserfs-devel@vger.kernel.org

    Deepa Dinamani
     

02 May, 2019

1 commit


23 May, 2018

1 commit


28 Nov, 2017

1 commit

  • 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
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

25 Jan, 2017

1 commit

  • Commit 8a59f5d25265 ("fs/romfs: return f_fsid for statfs(2)") generates
    a 64bit id from sb->s_bdev->bd_dev. This is only correct when romfs is
    defined with CONFIG_ROMFS_ON_BLOCK. If romfs is only defined with
    CONFIG_ROMFS_ON_MTD, sb->s_bdev is NULL, referencing sb->s_bdev->bd_dev
    will triger an oops.

    Richard Weinberger points out that when CONFIG_ROMFS_BACKED_BY_BOTH=y,
    both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD are defined.
    Therefore when calling huge_encode_dev() to generate a 64bit id, I use
    the follow order to choose parameter,

    - CONFIG_ROMFS_ON_BLOCK defined
    use sb->s_bdev->bd_dev
    - CONFIG_ROMFS_ON_BLOCK undefined and CONFIG_ROMFS_ON_MTD defined
    use sb->s_dev when,
    - both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD undefined
    leave id as 0

    When CONFIG_ROMFS_ON_MTD is defined and sb->s_mtd is not NULL, sb->s_dev
    is set to a device ID generated by MTD_BLOCK_MAJOR and mtd index,
    otherwise sb->s_dev is 0.

    This is a try-best effort to generate a uniq file system ID, if all the
    above conditions are not meet, f_fsid of this romfs instance will be 0.
    Generally only one romfs can be built on single MTD block device, this
    method is enough to identify multiple romfs instances in a computer.

    Link: http://lkml.kernel.org/r/1482928596-115155-1-git-send-email-colyli@suse.de
    Signed-off-by: Coly Li
    Reported-by: Nong Li
    Tested-by: Nong Li
    Cc: Richard Weinberger
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Coly Li
     

09 May, 2016

1 commit


15 Jan, 2016

1 commit

  • Mark those kmem allocations that are known to be easily triggered from
    userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
    memcg. For the list, see below:

    - threadinfo
    - task_struct
    - task_delay_info
    - pid
    - cred
    - mm_struct
    - vm_area_struct and vm_region (nommu)
    - anon_vma and anon_vma_chain
    - signal_struct
    - sighand_struct
    - fs_struct
    - files_struct
    - fdtable and fdtable->full_fds_bits
    - dentry and external_name
    - inode for all filesystems. This is the most tedious part, because
    most filesystems overwrite the alloc_inode method.

    The list is far from complete, so feel free to add more objects.
    Nevertheless, it should be close to "account everything" approach and
    keep most workloads within bounds. Malevolent users will be able to
    breach the limit, but this was possible even with the former "account
    everything" approach (simply because it did not account everything in
    fact).

    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: Vladimir Davydov
    Acked-by: Johannes Weiner
    Acked-by: Michal Hocko
    Cc: Tejun Heo
    Cc: Greg Thelen
    Cc: Christoph Lameter
    Cc: Pekka Enberg
    Cc: David Rientjes
    Cc: Joonsoo Kim
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Vladimir Davydov
     

09 Dec, 2015

1 commit

  • kmap() in page_follow_link_light() needed to go - allowing to hold
    an arbitrary number of kmaps for long is a great way to deadlocking
    the system.

    new helper (inode_nohighmem(inode)) needs to be used for pagecache
    symlinks inodes; done for all in-tree cases. page_follow_link_light()
    instrumented to yell about anything missed.

    Signed-off-by: Al Viro

    Al Viro
     

21 Jan, 2015

1 commit

  • Now that we never use the backing_dev_info pointer in struct address_space
    we can simply remove it and save 4 to 8 bytes in every inode.

    Signed-off-by: Christoph Hellwig
    Acked-by: Ryusuke Konishi
    Reviewed-by: Tejun Heo
    Reviewed-by: Jan Kara
    Signed-off-by: Jens Axboe

    Christoph Hellwig
     

09 Aug, 2014

3 commits


13 Mar, 2014

1 commit

  • Previously, the no-op "mount -o mount /dev/xxx" operation when the
    file system is already mounted read-write causes an implied,
    unconditional syncfs(). This seems pretty stupid, and it's certainly
    documented or guaraunteed to do this, nor is it particularly useful,
    except in the case where the file system was mounted rw and is getting
    remounted read-only.

    However, it's possible that there might be some file systems that are
    actually depending on this behavior. In most file systems, it's
    probably fine to only call sync_filesystem() when transitioning from
    read-write to read-only, and there are some file systems where this is
    not needed at all (for example, for a pseudo-filesystem or something
    like romfs).

    Signed-off-by: "Theodore Ts'o"
    Cc: linux-fsdevel@vger.kernel.org
    Cc: Christoph Hellwig
    Cc: Artem Bityutskiy
    Cc: Adrian Hunter
    Cc: Evgeniy Dushistov
    Cc: Jan Kara
    Cc: OGAWA Hirofumi
    Cc: Anders Larsen
    Cc: Phillip Lougher
    Cc: Kees Cook
    Cc: Mikulas Patocka
    Cc: Petr Vandrovec
    Cc: xfs@oss.sgi.com
    Cc: linux-btrfs@vger.kernel.org
    Cc: linux-cifs@vger.kernel.org
    Cc: samba-technical@lists.samba.org
    Cc: codalist@coda.cs.cmu.edu
    Cc: linux-ext4@vger.kernel.org
    Cc: linux-f2fs-devel@lists.sourceforge.net
    Cc: fuse-devel@lists.sourceforge.net
    Cc: cluster-devel@redhat.com
    Cc: linux-mtd@lists.infradead.org
    Cc: jfs-discussion@lists.sourceforge.net
    Cc: linux-nfs@vger.kernel.org
    Cc: linux-nilfs@vger.kernel.org
    Cc: linux-ntfs-dev@lists.sourceforge.net
    Cc: ocfs2-devel@oss.oracle.com
    Cc: reiserfs-devel@vger.kernel.org

    Theodore Ts'o
     

24 Jan, 2014

1 commit


29 Jun, 2013

1 commit


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
     

23 Feb, 2013

1 commit


03 Oct, 2012

1 commit

  • There's no reason to call rcu_barrier() on every
    deactivate_locked_super(). We only need to make sure that all delayed rcu
    free inodes are flushed before we destroy related cache.

    Removing rcu_barrier() from deactivate_locked_super() affects some fast
    paths. E.g. on my machine exit_group() of a last process in IPC
    namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time.

    Signed-off-by: Kirill A. Shutemov
    Cc: Al Viro
    Signed-off-by: Andrew Morton
    Signed-off-by: Al Viro

    Kirill A. Shutemov
     

14 Jul, 2012

1 commit

  • Just the flags; only NFS cares even about that, but there are
    legitimate uses for such argument. And getting rid of that
    completely would require splitting ->lookup() into a couple
    of methods (at least), so let's leave that alone for now...

    Signed-off-by: Al Viro

    Al Viro
     

21 Mar, 2012

1 commit


04 Jan, 2012

1 commit

  • Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
    it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
    the cost of taking it into inode_init_always() will be negligible for pipes
    and sockets and negative for everything else. Not to mention the removal of
    boilerplate code from ->destroy_inode() instances...

    Signed-off-by: Al Viro

    Al Viro
     

02 Nov, 2011

1 commit


07 Jan, 2011

1 commit

  • RCU free the struct inode. This will allow:

    - Subsequent store-free path walking patch. The inode must be consulted for
    permissions when walking, so an RCU inode reference is a must.
    - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
    to take i_lock no longer need to take sb_inode_list_lock to walk the list in
    the first place. This will simplify and optimize locking.
    - Could remove some nested trylock loops in dcache code
    - Could potentially simplify things a bit in VM land. Do not need to take the
    page lock to follow page->mapping.

    The downsides of this is the performance cost of using RCU. In a simple
    creat/unlink microbenchmark, performance drops by about 10% due to inability to
    reuse cache-hot slab objects. As iterations increase and RCU freeing starts
    kicking over, this increases to about 20%.

    In cases where inode lifetimes are longer (ie. many inodes may be allocated
    during the average life span of a single inode), a lot of this cache reuse is
    not applicable, so the regression caused by this patch is smaller.

    The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
    however this adds some complexity to list walking and store-free path walking,
    so I prefer to implement this at a later date, if it is shown to be a win in
    real situations. I haven't found a regression in any non-micro benchmark so I
    doubt it will be a problem.

    Signed-off-by: Nick Piggin

    Nick Piggin
     

29 Oct, 2010

1 commit


15 Oct, 2010

1 commit

  • All file_operations should get a .llseek operation so we can make
    nonseekable_open the default for future file operations without a
    .llseek pointer.

    The three cases that we can automatically detect are no_llseek, seq_lseek
    and default_llseek. For cases where we can we can automatically prove that
    the file offset is always ignored, we use noop_llseek, which maintains
    the current behavior of not returning an error from a seek.

    New drivers should normally not use noop_llseek but instead use no_llseek
    and call nonseekable_open at open time. Existing drivers can be converted
    to do the same when the maintainer knows for certain that no user code
    relies on calling seek on the device file.

    The generated code is often incorrectly indented and right now contains
    comments that clarify for each added line why a specific variant was
    chosen. In the version that gets submitted upstream, the comments will
    be gone and I will manually fix the indentation, because there does not
    seem to be a way to do that using coccinelle.

    Some amount of new code is currently sitting in linux-next that should get
    the same modifications, which I will do at the end of the merge window.

    Many thanks to Julia Lawall for helping me learn to write a semantic
    patch that does all this.

    ===== begin semantic patch =====
    // This adds an llseek= method to all file operations,
    // as a preparation for making no_llseek the default.
    //
    // The rules are
    // - use no_llseek explicitly if we do nonseekable_open
    // - use seq_lseek for sequential files
    // - use default_llseek if we know we access f_pos
    // - use noop_llseek if we know we don't access f_pos,
    // but we still want to allow users to call lseek
    //
    @ open1 exists @
    identifier nested_open;
    @@
    nested_open(...)
    {

    }

    @ open exists@
    identifier open_f;
    identifier i, f;
    identifier open1.nested_open;
    @@
    int open_f(struct inode *i, struct file *f)
    {

    }

    @ read disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {

    }

    @ read_no_fpos disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ write @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {

    }

    @ write_no_fpos @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ fops0 @
    identifier fops;
    @@
    struct file_operations fops = {
    ...
    };

    @ has_llseek depends on fops0 @
    identifier fops0.fops;
    identifier llseek_f;
    @@
    struct file_operations fops = {
    ...
    .llseek = llseek_f,
    ...
    };

    @ has_read depends on fops0 @
    identifier fops0.fops;
    identifier read_f;
    @@
    struct file_operations fops = {
    ...
    .read = read_f,
    ...
    };

    @ has_write depends on fops0 @
    identifier fops0.fops;
    identifier write_f;
    @@
    struct file_operations fops = {
    ...
    .write = write_f,
    ...
    };

    @ has_open depends on fops0 @
    identifier fops0.fops;
    identifier open_f;
    @@
    struct file_operations fops = {
    ...
    .open = open_f,
    ...
    };

    // use no_llseek if we call nonseekable_open
    ////////////////////////////////////////////
    @ nonseekable1 depends on !has_llseek && has_open @
    identifier fops0.fops;
    identifier nso ~= "nonseekable_open";
    @@
    struct file_operations fops = {
    ... .open = nso, ...
    +.llseek = no_llseek, /* nonseekable */
    };

    @ nonseekable2 depends on !has_llseek @
    identifier fops0.fops;
    identifier open.open_f;
    @@
    struct file_operations fops = {
    ... .open = open_f, ...
    +.llseek = no_llseek, /* open uses nonseekable */
    };

    // use seq_lseek for sequential files
    /////////////////////////////////////
    @ seq depends on !has_llseek @
    identifier fops0.fops;
    identifier sr ~= "seq_read";
    @@
    struct file_operations fops = {
    ... .read = sr, ...
    +.llseek = seq_lseek, /* we have seq_read */
    };

    // use default_llseek if there is a readdir
    ///////////////////////////////////////////
    @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier readdir_e;
    @@
    // any other fop is used that changes pos
    struct file_operations fops = {
    ... .readdir = readdir_e, ...
    +.llseek = default_llseek, /* readdir is present */
    };

    // use default_llseek if at least one of read/write touches f_pos
    /////////////////////////////////////////////////////////////////
    @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read.read_f;
    @@
    // read fops use offset
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = default_llseek, /* read accesses f_pos */
    };

    @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ... .write = write_f, ...
    + .llseek = default_llseek, /* write accesses f_pos */
    };

    // Use noop_llseek if neither read nor write accesses f_pos
    ///////////////////////////////////////////////////////////

    @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    identifier write_no_fpos.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ...
    .write = write_f,
    .read = read_f,
    ...
    +.llseek = noop_llseek, /* read and write both use no f_pos */
    };

    @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write_no_fpos.write_f;
    @@
    struct file_operations fops = {
    ... .write = write_f, ...
    +.llseek = noop_llseek, /* write uses no f_pos */
    };

    @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    @@
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = noop_llseek, /* read uses no f_pos */
    };

    @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    @@
    struct file_operations fops = {
    ...
    +.llseek = noop_llseek, /* no read or write fn */
    };
    ===== End semantic patch =====

    Signed-off-by: Arnd Bergmann
    Cc: Julia Lawall
    Cc: Christoph Hellwig

    Arnd Bergmann
     

27 Jan, 2010

1 commit


24 Sep, 2009

1 commit

  • romfs_iget returns an ERR_PTR value in an error case instead of NULL.

    A simplified version of the semantic match that finds this problem is as
    follows: (http://coccinelle.lip6.fr/)

    //
    @match exists@
    expression x, E;
    statement S1, S2;
    @@

    x = romfs_iget(...)
    ... when != x = E
    (
    * if (x == NULL || ...) S1 else S2
    |
    * if (x == NULL && ...) S1 else S2
    )
    //

    Signed-off-by: Julia Lawall
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Julia Lawall
     

22 Sep, 2009

1 commit


09 May, 2009

1 commit


25 Apr, 2009

1 commit


07 Apr, 2009

1 commit


24 Mar, 2009

1 commit

  • Change RomFS so that it can use MTD devices directly - without the intercession
    of the block layer - as well as using block devices.

    This permits RomFS:

    (1) to use the MTD direct mapping facility available under NOMMU conditions if
    the underlying device is directly accessible by the CPU (including XIP);

    (2) and thus to be used when the block layer is disabled.

    RomFS can be configured with support just for MTD devices, just for Block
    devices or for both. If RomFS is configured for both, then it will treat
    mtdblock device files as MTD backing stores, not block layer backing stores.

    I tested this using a CONFIG_MMU=n CONFIG_BLOCK=n kernel running on my FRV
    board with a RomFS image installed on the mtdram test device. I see my test
    program being run XIP:

    # cat /proc/maps
    ...
    c0c000b0-c0c01f8c r-xs 00000000 1f:00 144 /mnt/doshm
    ...

    GDB on the kernel can be used to show that these addresses are within the
    set-aside RAM space.

    Signed-off-by: David Howells
    Tested-by: Bernd Schmidt
    Signed-off-by: David Woodhouse

    David Howells