Adds a new ioctl command to look up pathnames of an inode from its
inode number.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxxxxxx>
---
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
--
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