diff options
Diffstat (limited to 'fs/stat.c')
| -rw-r--r-- | fs/stat.c | 223 |
1 files changed, 179 insertions, 44 deletions
diff --git a/fs/stat.c b/fs/stat.c index bc045c7994e1..c6c963b2546b 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -12,12 +12,22 @@ #include <linux/fs.h> #include <linux/namei.h> #include <linux/security.h> +#include <linux/cred.h> #include <linux/syscalls.h> #include <linux/pagemap.h> -#include <asm/uaccess.h> +#include <linux/uaccess.h> #include <asm/unistd.h> +/** + * generic_fillattr - Fill in the basic attributes from the inode struct + * @inode: Inode to use as the source + * @stat: Where to fill in the attributes + * + * Fill in the basic attributes in the kstat structure from data that's to be + * found on the VFS inode structure. This is the default if no getattr inode + * operation is supplied. + */ void generic_fillattr(struct inode *inode, struct kstat *stat) { stat->dev = inode->i_sb->s_dev; @@ -31,83 +41,150 @@ void generic_fillattr(struct inode *inode, struct kstat *stat) stat->atime = inode->i_atime; stat->mtime = inode->i_mtime; stat->ctime = inode->i_ctime; - stat->blksize = (1 << inode->i_blkbits); + stat->blksize = i_blocksize(inode); stat->blocks = inode->i_blocks; -} + if (IS_NOATIME(inode)) + stat->result_mask &= ~STATX_ATIME; + if (IS_AUTOMOUNT(inode)) + stat->attributes |= STATX_ATTR_AUTOMOUNT; +} EXPORT_SYMBOL(generic_fillattr); /** * vfs_getattr_nosec - getattr without security checks * @path: file to get attributes from * @stat: structure to return attributes in + * @request_mask: STATX_xxx flags indicating what the caller wants + * @query_flags: Query mode (KSTAT_QUERY_FLAGS) * * Get attributes without calling security_inode_getattr. * * Currently the only caller other than vfs_getattr is internal to the - * filehandle lookup code, which uses only the inode number and returns - * no attributes to any user. Any other code probably wants - * vfs_getattr. + * filehandle lookup code, which uses only the inode number and returns no + * attributes to any user. Any other code probably wants vfs_getattr. */ -int vfs_getattr_nosec(struct path *path, struct kstat *stat) +int vfs_getattr_nosec(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int query_flags) { struct inode *inode = d_backing_inode(path->dentry); + memset(stat, 0, sizeof(*stat)); + stat->result_mask |= STATX_BASIC_STATS; + request_mask &= STATX_ALL; + query_flags &= KSTAT_QUERY_FLAGS; if (inode->i_op->getattr) - return inode->i_op->getattr(path->mnt, path->dentry, stat); + return inode->i_op->getattr(path, stat, request_mask, + query_flags); generic_fillattr(inode, stat); return 0; } - EXPORT_SYMBOL(vfs_getattr_nosec); -int vfs_getattr(struct path *path, struct kstat *stat) +/* + * vfs_getattr - Get the enhanced basic attributes of a file + * @path: The file of interest + * @stat: Where to return the statistics + * @request_mask: STATX_xxx flags indicating what the caller wants + * @query_flags: Query mode (KSTAT_QUERY_FLAGS) + * + * Ask the filesystem for a file's attributes. The caller must indicate in + * request_mask and query_flags to indicate what they want. + * + * If the file is remote, the filesystem can be forced to update the attributes + * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can + * suppress the update by passing AT_STATX_DONT_SYNC. + * + * Bits must have been set in request_mask to indicate which attributes the + * caller wants retrieving. Any such attribute not requested may be returned + * anyway, but the value may be approximate, and, if remote, may not have been + * synchronised with the server. + * + * 0 will be returned on success, and a -ve error code if unsuccessful. + */ +int vfs_getattr(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int query_flags) { int retval; retval = security_inode_getattr(path); if (retval) return retval; - return vfs_getattr_nosec(path, stat); + return vfs_getattr_nosec(path, stat, request_mask, query_flags); } - EXPORT_SYMBOL(vfs_getattr); -int vfs_fstat(unsigned int fd, struct kstat *stat) +/** + * vfs_statx_fd - Get the enhanced basic attributes by file descriptor + * @fd: The file descriptor referring to the file of interest + * @stat: The result structure to fill in. + * @request_mask: STATX_xxx flags indicating what the caller wants + * @query_flags: Query mode (KSTAT_QUERY_FLAGS) + * + * This function is a wrapper around vfs_getattr(). The main difference is + * that it uses a file descriptor to determine the file location. + * + * 0 will be returned on success, and a -ve error code if unsuccessful. + */ +int vfs_statx_fd(unsigned int fd, struct kstat *stat, + u32 request_mask, unsigned int query_flags) { - struct fd f = fdget_raw(fd); + struct fd f; int error = -EBADF; + if (query_flags & ~KSTAT_QUERY_FLAGS) + return -EINVAL; + + f = fdget_raw(fd); if (f.file) { - error = vfs_getattr(&f.file->f_path, stat); + error = vfs_getattr(&f.file->f_path, stat, + request_mask, query_flags); fdput(f); } return error; } -EXPORT_SYMBOL(vfs_fstat); +EXPORT_SYMBOL(vfs_statx_fd); -int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, - int flag) +/** + * vfs_statx - Get basic and extra attributes by filename + * @dfd: A file descriptor representing the base dir for a relative filename + * @filename: The name of the file of interest + * @flags: Flags to control the query + * @stat: The result structure to fill in. + * @request_mask: STATX_xxx flags indicating what the caller wants + * + * This function is a wrapper around vfs_getattr(). The main difference is + * that it uses a filename and base directory to determine the file location. + * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink + * at the given name from being referenced. + * + * 0 will be returned on success, and a -ve error code if unsuccessful. + */ +int vfs_statx(int dfd, const char __user *filename, int flags, + struct kstat *stat, u32 request_mask) { struct path path; int error = -EINVAL; - unsigned int lookup_flags = 0; + unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT; - if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | - AT_EMPTY_PATH)) != 0) - goto out; + if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | + AT_EMPTY_PATH | KSTAT_QUERY_FLAGS)) != 0) + return -EINVAL; - if (!(flag & AT_SYMLINK_NOFOLLOW)) - lookup_flags |= LOOKUP_FOLLOW; - if (flag & AT_EMPTY_PATH) + if (flags & AT_SYMLINK_NOFOLLOW) + lookup_flags &= ~LOOKUP_FOLLOW; + if (flags & AT_NO_AUTOMOUNT) + lookup_flags &= ~LOOKUP_AUTOMOUNT; + if (flags & AT_EMPTY_PATH) lookup_flags |= LOOKUP_EMPTY; + retry: error = user_path_at(dfd, filename, lookup_flags, &path); if (error) goto out; - error = vfs_getattr(&path, stat); + error = vfs_getattr(&path, stat, request_mask, flags); path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; @@ -116,19 +193,7 @@ retry: out: return error; } -EXPORT_SYMBOL(vfs_fstatat); - -int vfs_stat(const char __user *name, struct kstat *stat) -{ - return vfs_fstatat(AT_FDCWD, name, stat, 0); -} -EXPORT_SYMBOL(vfs_stat); - -int vfs_lstat(const char __user *name, struct kstat *stat) -{ - return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW); -} -EXPORT_SYMBOL(vfs_lstat); +EXPORT_SYMBOL(vfs_statx); #ifdef __ARCH_WANT_OLD_STAT @@ -141,7 +206,7 @@ static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * sta { static int warncount = 5; struct __old_kernel_stat tmp; - + if (warncount > 0) { warncount--; printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", @@ -166,7 +231,7 @@ static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * sta #if BITS_PER_LONG == 32 if (stat->size > MAX_NON_LFS) return -EOVERFLOW; -#endif +#endif tmp.st_size = stat->size; tmp.st_atime = stat->atime.tv_sec; tmp.st_mtime = stat->mtime.tv_sec; @@ -329,12 +394,14 @@ retry: struct inode *inode = d_backing_inode(path.dentry); error = empty ? -ENOENT : -EINVAL; - if (inode->i_op->readlink) { + /* + * AFS mountpoints allow readlink(2) but are not symlinks + */ + if (d_is_symlink(path.dentry) || inode->i_op->readlink) { error = security_inode_readlink(path.dentry); if (!error) { touch_atime(&path); - error = inode->i_op->readlink(path.dentry, - buf, bufsiz); + error = vfs_readlink(path.dentry, buf, bufsiz); } } path_put(&path); @@ -443,6 +510,74 @@ SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename, } #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */ +static noinline_for_stack int +cp_statx(const struct kstat *stat, struct statx __user *buffer) +{ + struct statx tmp; + + memset(&tmp, 0, sizeof(tmp)); + + tmp.stx_mask = stat->result_mask; + tmp.stx_blksize = stat->blksize; + tmp.stx_attributes = stat->attributes; + tmp.stx_nlink = stat->nlink; + tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid); + tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid); + tmp.stx_mode = stat->mode; + tmp.stx_ino = stat->ino; + tmp.stx_size = stat->size; + tmp.stx_blocks = stat->blocks; + tmp.stx_attributes_mask = stat->attributes_mask; + tmp.stx_atime.tv_sec = stat->atime.tv_sec; + tmp.stx_atime.tv_nsec = stat->atime.tv_nsec; + tmp.stx_btime.tv_sec = stat->btime.tv_sec; + tmp.stx_btime.tv_nsec = stat->btime.tv_nsec; + tmp.stx_ctime.tv_sec = stat->ctime.tv_sec; + tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec; + tmp.stx_mtime.tv_sec = stat->mtime.tv_sec; + tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec; + tmp.stx_rdev_major = MAJOR(stat->rdev); + tmp.stx_rdev_minor = MINOR(stat->rdev); + tmp.stx_dev_major = MAJOR(stat->dev); + tmp.stx_dev_minor = MINOR(stat->dev); + + return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0; +} + +/** + * sys_statx - System call to get enhanced stats + * @dfd: Base directory to pathwalk from *or* fd to stat. + * @filename: File to stat *or* NULL. + * @flags: AT_* flags to control pathwalk. + * @mask: Parts of statx struct actually required. + * @buffer: Result buffer. + * + * Note that if filename is NULL, then it does the equivalent of fstat() using + * dfd to indicate the file of interest. + */ +SYSCALL_DEFINE5(statx, + int, dfd, const char __user *, filename, unsigned, flags, + unsigned int, mask, + struct statx __user *, buffer) +{ + struct kstat stat; + int error; + + if (mask & STATX__RESERVED) + return -EINVAL; + if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE) + return -EINVAL; + + if (filename) + error = vfs_statx(dfd, filename, flags, &stat, mask); + else + error = vfs_statx_fd(dfd, &stat, mask, flags); + if (error) + return error; + + return cp_statx(&stat, buffer); +} + /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */ void __inode_add_bytes(struct inode *inode, loff_t bytes) { |