diff options
Diffstat (limited to 'fs/statfs.c')
| -rw-r--r-- | fs/statfs.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/fs/statfs.c b/fs/statfs.c new file mode 100644 index 00000000000..30ea8c8a996 --- /dev/null +++ b/fs/statfs.c @@ -0,0 +1,243 @@ +#include <linux/syscalls.h> +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <linux/statfs.h> +#include <linux/security.h> +#include <linux/uaccess.h> + +static int flags_by_mnt(int mnt_flags) +{ + int flags = 0; + + if (mnt_flags & MNT_READONLY) + flags |= ST_RDONLY; + if (mnt_flags & MNT_NOSUID) + flags |= ST_NOSUID; + if (mnt_flags & MNT_NODEV) + flags |= ST_NODEV; + if (mnt_flags & MNT_NOEXEC) + flags |= ST_NOEXEC; + if (mnt_flags & MNT_NOATIME) + flags |= ST_NOATIME; + if (mnt_flags & MNT_NODIRATIME) + flags |= ST_NODIRATIME; + if (mnt_flags & MNT_RELATIME) + flags |= ST_RELATIME; + return flags; +} + +static int flags_by_sb(int s_flags) +{ + int flags = 0; + if (s_flags & MS_SYNCHRONOUS) + flags |= ST_SYNCHRONOUS; + if (s_flags & MS_MANDLOCK) + flags |= ST_MANDLOCK; + return flags; +} + +static int calculate_f_flags(struct vfsmount *mnt) +{ + return ST_VALID | flags_by_mnt(mnt->mnt_flags) | + flags_by_sb(mnt->mnt_sb->s_flags); +} + +int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf) +{ + int retval; + + if (!dentry->d_sb->s_op->statfs) + return -ENOSYS; + + memset(buf, 0, sizeof(*buf)); + retval = security_sb_statfs(dentry); + if (retval) + return retval; + retval = dentry->d_sb->s_op->statfs(dentry, buf); + if (retval == 0 && buf->f_frsize == 0) + buf->f_frsize = buf->f_bsize; + return retval; +} + +int vfs_statfs(struct path *path, struct kstatfs *buf) +{ + int error; + + error = statfs_by_dentry(path->dentry, buf); + if (!error) + buf->f_flags = calculate_f_flags(path->mnt); + return error; +} +EXPORT_SYMBOL(vfs_statfs); + +static int do_statfs_native(struct path *path, struct statfs *buf) +{ + struct kstatfs st; + int retval; + + retval = vfs_statfs(path, &st); + if (retval) + return retval; + + if (sizeof(*buf) == sizeof(st)) + memcpy(buf, &st, sizeof(st)); + else { + if (sizeof buf->f_blocks == 4) { + if ((st.f_blocks | st.f_bfree | st.f_bavail | + st.f_bsize | st.f_frsize) & + 0xffffffff00000000ULL) + return -EOVERFLOW; + /* + * f_files and f_ffree may be -1; it's okay to stuff + * that into 32 bits + */ + if (st.f_files != -1 && + (st.f_files & 0xffffffff00000000ULL)) + return -EOVERFLOW; + if (st.f_ffree != -1 && + (st.f_ffree & 0xffffffff00000000ULL)) + return -EOVERFLOW; + } + + buf->f_type = st.f_type; + buf->f_bsize = st.f_bsize; + buf->f_blocks = st.f_blocks; + buf->f_bfree = st.f_bfree; + buf->f_bavail = st.f_bavail; + buf->f_files = st.f_files; + buf->f_ffree = st.f_ffree; + buf->f_fsid = st.f_fsid; + buf->f_namelen = st.f_namelen; + buf->f_frsize = st.f_frsize; + buf->f_flags = st.f_flags; + memset(buf->f_spare, 0, sizeof(buf->f_spare)); + } + return 0; +} + +static int do_statfs64(struct path *path, struct statfs64 *buf) +{ + struct kstatfs st; + int retval; + + retval = vfs_statfs(path, &st); + if (retval) + return retval; + + if (sizeof(*buf) == sizeof(st)) + memcpy(buf, &st, sizeof(st)); + else { + buf->f_type = st.f_type; + buf->f_bsize = st.f_bsize; + buf->f_blocks = st.f_blocks; + buf->f_bfree = st.f_bfree; + buf->f_bavail = st.f_bavail; + buf->f_files = st.f_files; + buf->f_ffree = st.f_ffree; + buf->f_fsid = st.f_fsid; + buf->f_namelen = st.f_namelen; + buf->f_frsize = st.f_frsize; + buf->f_flags = st.f_flags; + memset(buf->f_spare, 0, sizeof(buf->f_spare)); + } + return 0; +} + +SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, buf) +{ + struct path path; + int error; + + error = user_path(pathname, &path); + if (!error) { + struct statfs tmp; + error = do_statfs_native(&path, &tmp); + if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) + error = -EFAULT; + path_put(&path); + } + return error; +} + +SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct statfs64 __user *, buf) +{ + struct path path; + long error; + + if (sz != sizeof(*buf)) + return -EINVAL; + error = user_path(pathname, &path); + if (!error) { + struct statfs64 tmp; + error = do_statfs64(&path, &tmp); + if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) + error = -EFAULT; + path_put(&path); + } + return error; +} + +SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf) +{ + struct file *file; + struct statfs tmp; + int error; + + error = -EBADF; + file = fget(fd); + if (!file) + goto out; + error = do_statfs_native(&file->f_path, &tmp); + if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) + error = -EFAULT; + fput(file); +out: + return error; +} + +SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf) +{ + struct file *file; + struct statfs64 tmp; + int error; + + if (sz != sizeof(*buf)) + return -EINVAL; + + error = -EBADF; + file = fget(fd); + if (!file) + goto out; + error = do_statfs64(&file->f_path, &tmp); + if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) + error = -EFAULT; + fput(file); +out: + return error; +} + +SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf) +{ + struct super_block *s; + struct ustat tmp; + struct kstatfs sbuf; + int err; + + s = user_get_super(new_decode_dev(dev)); + if (!s) + return -EINVAL; + + err = statfs_by_dentry(s->s_root, &sbuf); + drop_super(s); + if (err) + return err; + + memset(&tmp,0,sizeof(struct ustat)); + tmp.f_tfree = sbuf.f_bfree; + tmp.f_tinode = sbuf.f_ffree; + + return copy_to_user(ubuf, &tmp, sizeof(struct ustat)) ? -EFAULT : 0; +} |