lkml.org 
[lkml]   [2007]   [May]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[stable] [PATCH] - fix oops in sysfs_readdir
    This is a non-ida backport of Tejun's patch in -mm at:
    ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.22-rc1/2.6.22-rc1-mm1/broken-out/gregkh-driver-sysfs-allocate-inode-number-using-ida.patch
    for the 2.6.16 -stable tree - it follows the same scheme of using s_ino to safely
    store & retrieve the inode number of sysfs entries for use in sysfs_readdir,
    but uses a brain-dead-simple inode nr allocator rather than ida, which would
    bring along a lot of newer, more complex code.

    No, this doesn't guarantee uniqueness of sysfs inode numbers, but then
    the code in -stable today doesn't either - and with this change, at least
    it shouldn't oops.

    Comments?

    Thanks,

    -Eric

    Signed-off-by: Eric Sandeen <sandeen@redhat.com>

    Index: linux-2.6.16.51/fs/sysfs/dir.c
    ===================================================================
    --- linux-2.6.16.51.orig/fs/sysfs/dir.c
    +++ linux-2.6.16.51/fs/sysfs/dir.c
    @@ -29,6 +29,14 @@ static struct dentry_operations sysfs_de
    .d_iput = sysfs_d_iput,
    };

    +static unsigned int sysfs_inode_counter;
    +ino_t sysfs_get_inum(void)
    +{
    + if (unlikely(sysfs_inode_counter < 3))
    + sysfs_inode_counter = 3;
    + return sysfs_inode_counter++;
    +}
    +
    /*
    * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
    */
    @@ -385,7 +393,7 @@ static int sysfs_readdir(struct file * f

    switch (i) {
    case 0:
    - ino = dentry->d_inode->i_ino;
    + ino = parent_sd->s_ino;
    if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
    break;
    filp->f_pos++;
    @@ -415,10 +423,7 @@ static int sysfs_readdir(struct file * f

    name = sysfs_get_name(next);
    len = strlen(name);
    - if (next->s_dentry)
    - ino = next->s_dentry->d_inode->i_ino;
    - else
    - ino = iunique(sysfs_sb, 2);
    + ino = next->s_ino;

    if (filldir(dirent, name, len, filp->f_pos, ino,
    dt_type(next)) < 0)
    Index: linux-2.6.16.51/fs/sysfs/inode.c
    ===================================================================
    --- linux-2.6.16.51.orig/fs/sysfs/inode.c
    +++ linux-2.6.16.51/fs/sysfs/inode.c
    @@ -119,6 +119,7 @@ struct inode * sysfs_new_inode(mode_t mo
    inode->i_mapping->a_ops = &sysfs_aops;
    inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
    inode->i_op = &sysfs_inode_operations;
    + inode->i_ino = sd->s_ino;

    if (sd->s_iattr) {
    /* sysfs_dirent has non-default attributes
    Index: linux-2.6.16.51/fs/sysfs/mount.c
    ===================================================================
    --- linux-2.6.16.51.orig/fs/sysfs/mount.c
    +++ linux-2.6.16.51/fs/sysfs/mount.c
    @@ -29,6 +29,7 @@ static struct sysfs_dirent sysfs_root =
    .s_element = NULL,
    .s_type = SYSFS_ROOT,
    .s_iattr = NULL,
    + .s_ino = 1,
    };

    static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
    Index: linux-2.6.16.51/include/linux/sysfs.h
    ===================================================================
    --- linux-2.6.16.51.orig/include/linux/sysfs.h
    +++ linux-2.6.16.51/include/linux/sysfs.h
    @@ -72,6 +72,7 @@ struct sysfs_dirent {
    void * s_element;
    int s_type;
    umode_t s_mode;
    + ino_t s_ino;
    struct dentry * s_dentry;
    struct iattr * s_iattr;
    };

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-05-21 20:21    [W:2.752 / U:0.228 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site