Adds a new ioctl command to look up pathnames of an inode from its inode number.
Signed-off-by: Ryusuke Konishi <[email protected]> --- fs/nilfs2/ioctl.c | 76 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/nilfs2_fs.h | 13 ++++++++ 2 files changed, 89 insertions(+), 0 deletions(-) diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c index 79f3719..cc468ff 100644 --- a/fs/nilfs2/ioctl.c +++ b/fs/nilfs2/ioctl.c @@ -812,6 +812,80 @@ out: return ret; } +/** + * nilfs_ioctl_ino_lookup - lookup pathname of inode + * @inode: inode on which this ioctl was issued + * @argp: pointer to nilfs_ino_lookup_args structure. Where the argv + * member holds the following information + * + * argv.v_nmembs: number of pathnames (used for both request and result) + * argv.v_base: buffer in which pathnames will be stored + * argv.v_size: size of pathnames buffer + * argv.v_index: index number of pathnames + */ +static int nilfs_ioctl_ino_lookup(struct inode *inode, void __user *argp) +{ + struct nilfs_ino_lookup_args largs; + struct nilfs_root *root; + size_t namesz, bufsz; + void *kbuf; + void __user *base; + int ret; + + ret = -EPERM; + if (!capable(CAP_SYS_ADMIN)) + goto out; + + ret = -EFAULT; + if (copy_from_user(&largs, argp, sizeof(largs))) + goto out; + + ret = 0; + if (largs.argv.v_nmembs == 0) + goto out; + + ret = -ERANGE; + if (largs.argv.v_size > 4096) + goto out; + + bufsz = largs.argv.v_size; + base = (void __user *)(unsigned long)largs.argv.v_base; + kbuf = kmalloc(bufsz, GFP_NOFS); + if (!kbuf) { + ret = -ENOMEM; + goto out; + } + + down_read(&inode->i_sb->s_umount); + + ret = nilfs_attach_checkpoint(inode->i_sb, largs.cno, false, &root); + if (ret < 0) + goto out_unlock; + + ret = nilfs_search_path(inode->i_sb, root, largs.ino, + largs.argv.v_index, kbuf, bufsz, &namesz); + if (ret >= 0) { + largs.argv.v_nmembs = ret; + largs.argv.v_size = namesz; + ret = 0; + } + nilfs_put_root(root); + +out_unlock: + up_read(&inode->i_sb->s_umount); + + if (!ret && copy_to_user(base, kbuf + bufsz - namesz, namesz)) + ret = -EFAULT; + + kfree(kbuf); + + if (!ret && copy_to_user(&((struct nilfs_ino_lookup_args *)argp)->argv, + &largs.argv, sizeof(largs.argv))) + ret = -EFAULT; +out: + return ret; +} + static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp, unsigned int cmd, void __user *argp, size_t membsz, @@ -883,6 +957,8 @@ long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return nilfs_ioctl_set_alloc_range(inode, argp); case NILFS_IOCTL_COMPARE_CHECKPOINTS: return nilfs_ioctl_compare_checkpoints(inode, argp); + case NILFS_IOCTL_INO_LOOKUP: + return nilfs_ioctl_ino_lookup(inode, argp); default: return -ENOTTY; } diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h index 599ccd1..9d2f425 100644 --- a/include/linux/nilfs2_fs.h +++ b/include/linux/nilfs2_fs.h @@ -863,6 +863,17 @@ struct nilfs_comp_args { struct nilfs_argv argv; }; +/** + * struct nilfs_ino_lookup_args - ioctl argument to lookup inode pathname + * @ino: inode number + * @cno: checkpoint number + * @argv: argument vector to exchange pathnames + */ +struct nilfs_ino_lookup_args { + __u64 ino; + __u64 cno; + struct nilfs_argv argv; +}; #define NILFS_IOCTL_IDENT 'n' @@ -892,5 +903,7 @@ struct nilfs_comp_args { _IOW(NILFS_IOCTL_IDENT, 0x8C, __u64[2]) #define NILFS_IOCTL_COMPARE_CHECKPOINTS \ _IOWR(NILFS_IOCTL_IDENT, 0x8D, struct nilfs_comp_args) +#define NILFS_IOCTL_INO_LOOKUP \ + _IOWR(NILFS_IOCTL_IDENT, 0x8E, struct nilfs_ino_lookup_args) #endif /* _LINUX_NILFS_FS_H */ -- 1.7.3.5 -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
