lkml.org 
[lkml]   [2010]   [Feb]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 01/11] ocfs2_dlmfs: Add capabilities parameter.
    Date
    Over time, dlmfs has added some features that were not part of the
    initial ABI. Unfortunately, some of these features are not detectable
    via standard usage. For example, Linux's default poll always returns
    POLLIN, so there is no way for a caller of poll(2) to know when dlmfs
    added poll support. Instead, we provide this list of new capabilities.

    Capabilities is a read-only attribute. We do it as a module parameter
    so we can discover it whether dlmfs is built in, loaded, or even not
    loaded (via modinfo).

    The ABI features are local to this machine's dlmfs mount. This is
    distinct from the locking protocol, which is concerned with inter-node
    interaction.

    Signed-off-by: Joel Becker <joel.becker@oracle.com>
    ---
    fs/ocfs2/dlm/dlmfs.c | 36 ++++++++++++++++++++++++++++++++++++
    1 files changed, 36 insertions(+), 0 deletions(-)

    diff --git a/fs/ocfs2/dlm/dlmfs.c b/fs/ocfs2/dlm/dlmfs.c
    index 02bf178..77d0df4 100644
    --- a/fs/ocfs2/dlm/dlmfs.c
    +++ b/fs/ocfs2/dlm/dlmfs.c
    @@ -81,6 +81,42 @@ static const struct dlm_protocol_version user_locking_protocol = {
    .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR,
    };

    +
    +/*
    + * These are the ABI capabilities of dlmfs.
    + *
    + * Over time, dlmfs has added some features that were not part of the
    + * initial ABI. Unfortunately, some of these features are not detectable
    + * via standard usage. For example, Linux's default poll always returns
    + * POLLIN, so there is no way for a caller of poll(2) to know when dlmfs
    + * added poll support. Instead, we provide this list of new capabilities.
    + *
    + * Capabilities is a read-only attribute. We do it as a module parameter
    + * so we can discover it whether dlmfs is built in, loaded, or even not
    + * loaded.
    + *
    + * The ABI features are local to this machine's dlmfs mount. This is
    + * distinct from the locking protocol, which is concerned with inter-node
    + * interaction.
    + */
    +#define DLMFS_CAPABILITIES ""
    +extern int param_set_dlmfs_capabilities(const char *val,
    + struct kernel_param *kp)
    +{
    + printk(KERN_ERR "%s: readonly parameter\n", kp->name);
    + return -EINVAL;
    +}
    +static int param_get_dlmfs_capabilities(char *buffer,
    + struct kernel_param *kp)
    +{
    + return strlcpy(buffer, DLMFS_CAPABILITIES,
    + strlen(DLMFS_CAPABILITIES) + 1);
    +}
    +module_param_call(capabilities, param_set_dlmfs_capabilities,
    + param_get_dlmfs_capabilities, NULL, 0444);
    +MODULE_PARM_DESC(capabilities, DLMFS_CAPABILITIES);
    +
    +
    /*
    * decodes a set of open flags into a valid lock level and a set of flags.
    * returns < 0 if we have invalid flags
    --
    1.6.6.1


    \
     
     \ /
      Last update: 2010-02-10 10:33    [W:0.031 / U:33.316 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site