diff options
Diffstat (limited to 'fs/stat.c')
| -rw-r--r-- | fs/stat.c | 860 |
1 files changed, 860 insertions, 0 deletions
diff --git a/fs/stat.c b/fs/stat.c new file mode 100644 index 0000000000..5375be5f97 --- /dev/null +++ b/fs/stat.c @@ -0,0 +1,860 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/stat.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + */ + +#include <linux/blkdev.h> +#include <linux/export.h> +#include <linux/mm.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/highuid.h> +#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 <linux/compat.h> +#include <linux/iversion.h> + +#include <linux/uaccess.h> +#include <asm/unistd.h> + +#include "internal.h" +#include "mount.h" + +/** + * generic_fillattr - Fill in the basic attributes from the inode struct + * @idmap: idmap of the mount the inode was found from + * @request_mask: statx request_mask + * @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. + * + * If the inode has been found through an idmapped mount the idmap of + * the vfsmount must be passed through @idmap. This function will then + * take care to map the inode according to @idmap before filling in the + * uid and gid filds. On non-idmapped mounts or if permission checking is to be + * performed on the raw inode simply passs @nop_mnt_idmap. + */ +void generic_fillattr(struct mnt_idmap *idmap, u32 request_mask, + struct inode *inode, struct kstat *stat) +{ + vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode); + vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode); + + stat->dev = inode->i_sb->s_dev; + stat->ino = inode->i_ino; + stat->mode = inode->i_mode; + stat->nlink = inode->i_nlink; + stat->uid = vfsuid_into_kuid(vfsuid); + stat->gid = vfsgid_into_kgid(vfsgid); + stat->rdev = inode->i_rdev; + stat->size = i_size_read(inode); + stat->atime = inode->i_atime; + stat->mtime = inode->i_mtime; + stat->ctime = inode_get_ctime(inode); + stat->blksize = i_blocksize(inode); + stat->blocks = inode->i_blocks; + + if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) { + stat->result_mask |= STATX_CHANGE_COOKIE; + stat->change_cookie = inode_query_iversion(inode); + } + +} +EXPORT_SYMBOL(generic_fillattr); + +/** + * generic_fill_statx_attr - Fill in the statx attributes from the inode flags + * @inode: Inode to use as the source + * @stat: Where to fill in the attribute flags + * + * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the + * inode that are published on i_flags and enforced by the VFS. + */ +void generic_fill_statx_attr(struct inode *inode, struct kstat *stat) +{ + if (inode->i_flags & S_IMMUTABLE) + stat->attributes |= STATX_ATTR_IMMUTABLE; + if (inode->i_flags & S_APPEND) + stat->attributes |= STATX_ATTR_APPEND; + stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS; +} +EXPORT_SYMBOL(generic_fill_statx_attr); + +/** + * 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 (AT_STATX_SYNC_TYPE) + * + * 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. + */ +int vfs_getattr_nosec(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int query_flags) +{ + struct mnt_idmap *idmap; + struct inode *inode = d_backing_inode(path->dentry); + + memset(stat, 0, sizeof(*stat)); + stat->result_mask |= STATX_BASIC_STATS; + query_flags &= AT_STATX_SYNC_TYPE; + + /* allow the fs to override these if it really wants to */ + /* SB_NOATIME means filesystem supplies dummy atime value */ + if (inode->i_sb->s_flags & SB_NOATIME) + stat->result_mask &= ~STATX_ATIME; + + /* + * Note: If you add another clause to set an attribute flag, please + * update attributes_mask below. + */ + if (IS_AUTOMOUNT(inode)) + stat->attributes |= STATX_ATTR_AUTOMOUNT; + + if (IS_DAX(inode)) + stat->attributes |= STATX_ATTR_DAX; + + stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT | + STATX_ATTR_DAX); + + idmap = mnt_idmap(path->mnt); + if (inode->i_op->getattr) + return inode->i_op->getattr(idmap, path, stat, + request_mask, + query_flags | AT_GETATTR_NOSEC); + + generic_fillattr(idmap, request_mask, inode, stat); + return 0; +} +EXPORT_SYMBOL(vfs_getattr_nosec); + +/* + * 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 (AT_STATX_SYNC_TYPE) + * + * 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; + + if (WARN_ON_ONCE(query_flags & AT_GETATTR_NOSEC)) + return -EPERM; + + retval = security_inode_getattr(path); + if (retval) + return retval; + return vfs_getattr_nosec(path, stat, request_mask, query_flags); +} +EXPORT_SYMBOL(vfs_getattr); + +/** + * vfs_fstat - Get the basic attributes by file descriptor + * @fd: The file descriptor referring to the file of interest + * @stat: The result structure to fill in. + * + * 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_fstat(int fd, struct kstat *stat) +{ + struct fd f; + int error; + + f = fdget_raw(fd); + if (!f.file) + return -EBADF; + error = vfs_getattr(&f.file->f_path, stat, STATX_BASIC_STATS, 0); + fdput(f); + return error; +} + +int getname_statx_lookup_flags(int flags) +{ + int lookup_flags = 0; + + 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; + + return lookup_flags; +} + +/** + * 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. + */ +static int vfs_statx(int dfd, struct filename *filename, int flags, + struct kstat *stat, u32 request_mask) +{ + struct path path; + unsigned int lookup_flags = getname_statx_lookup_flags(flags); + int error; + + if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH | + AT_STATX_SYNC_TYPE)) + return -EINVAL; + +retry: + error = filename_lookup(dfd, filename, lookup_flags, &path, NULL); + if (error) + goto out; + + error = vfs_getattr(&path, stat, request_mask, flags); + + stat->mnt_id = real_mount(path.mnt)->mnt_id; + stat->result_mask |= STATX_MNT_ID; + + if (path.mnt->mnt_root == path.dentry) + stat->attributes |= STATX_ATTR_MOUNT_ROOT; + stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT; + + /* Handle STATX_DIOALIGN for block devices. */ + if (request_mask & STATX_DIOALIGN) { + struct inode *inode = d_backing_inode(path.dentry); + + if (S_ISBLK(inode->i_mode)) + bdev_statx_dioalign(inode, stat); + } + + path_put(&path); + if (retry_estale(error, lookup_flags)) { + lookup_flags |= LOOKUP_REVAL; + goto retry; + } +out: + return error; +} + +int vfs_fstatat(int dfd, const char __user *filename, + struct kstat *stat, int flags) +{ + int ret; + int statx_flags = flags | AT_NO_AUTOMOUNT; + struct filename *name; + + /* + * Work around glibc turning fstat() into fstatat(AT_EMPTY_PATH) + * + * If AT_EMPTY_PATH is set, we expect the common case to be that + * empty path, and avoid doing all the extra pathname work. + */ + if (dfd >= 0 && flags == AT_EMPTY_PATH) { + char c; + + ret = get_user(c, filename); + if (unlikely(ret)) + return ret; + + if (likely(!c)) + return vfs_fstat(dfd, stat); + } + + name = getname_flags(filename, getname_statx_lookup_flags(statx_flags), NULL); + ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS); + putname(name); + + return ret; +} + +#ifdef __ARCH_WANT_OLD_STAT + +/* + * For backward compatibility? Maybe this should be moved + * into arch/i386 instead? + */ +static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) +{ + 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", + current->comm); + } else if (warncount < 0) { + /* it's laughable, but... */ + warncount = 0; + } + + memset(&tmp, 0, sizeof(struct __old_kernel_stat)); + tmp.st_dev = old_encode_dev(stat->dev); + tmp.st_ino = stat->ino; + if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) + return -EOVERFLOW; + tmp.st_mode = stat->mode; + tmp.st_nlink = stat->nlink; + if (tmp.st_nlink != stat->nlink) + return -EOVERFLOW; + SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); + SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); + tmp.st_rdev = old_encode_dev(stat->rdev); +#if BITS_PER_LONG == 32 + if (stat->size > MAX_NON_LFS) + return -EOVERFLOW; +#endif + tmp.st_size = stat->size; + tmp.st_atime = stat->atime.tv_sec; + tmp.st_mtime = stat->mtime.tv_sec; + tmp.st_ctime = stat->ctime.tv_sec; + return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; +} + +SYSCALL_DEFINE2(stat, const char __user *, filename, + struct __old_kernel_stat __user *, statbuf) +{ + struct kstat stat; + int error; + + error = vfs_stat(filename, &stat); + if (error) + return error; + + return cp_old_stat(&stat, statbuf); +} + +SYSCALL_DEFINE2(lstat, const char __user *, filename, + struct __old_kernel_stat __user *, statbuf) +{ + struct kstat stat; + int error; + + error = vfs_lstat(filename, &stat); + if (error) + return error; + + return cp_old_stat(&stat, statbuf); +} + +SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf) +{ + struct kstat stat; + int error = vfs_fstat(fd, &stat); + + if (!error) + error = cp_old_stat(&stat, statbuf); + + return error; +} + +#endif /* __ARCH_WANT_OLD_STAT */ + +#ifdef __ARCH_WANT_NEW_STAT + +#ifndef INIT_STRUCT_STAT_PADDING +# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st)) +#endif + +static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) +{ + struct stat tmp; + + if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev)) + return -EOVERFLOW; + if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev)) + return -EOVERFLOW; +#if BITS_PER_LONG == 32 + if (stat->size > MAX_NON_LFS) + return -EOVERFLOW; +#endif + + INIT_STRUCT_STAT_PADDING(tmp); + tmp.st_dev = new_encode_dev(stat->dev); + tmp.st_ino = stat->ino; + if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) + return -EOVERFLOW; + tmp.st_mode = stat->mode; + tmp.st_nlink = stat->nlink; + if (tmp.st_nlink != stat->nlink) + return -EOVERFLOW; + SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); + SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); + tmp.st_rdev = new_encode_dev(stat->rdev); + tmp.st_size = stat->size; + tmp.st_atime = stat->atime.tv_sec; + tmp.st_mtime = stat->mtime.tv_sec; + tmp.st_ctime = stat->ctime.tv_sec; +#ifdef STAT_HAVE_NSEC + tmp.st_atime_nsec = stat->atime.tv_nsec; + tmp.st_mtime_nsec = stat->mtime.tv_nsec; + tmp.st_ctime_nsec = stat->ctime.tv_nsec; +#endif + tmp.st_blocks = stat->blocks; + tmp.st_blksize = stat->blksize; + return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; +} + +SYSCALL_DEFINE2(newstat, const char __user *, filename, + struct stat __user *, statbuf) +{ + struct kstat stat; + int error = vfs_stat(filename, &stat); + + if (error) + return error; + return cp_new_stat(&stat, statbuf); +} + +SYSCALL_DEFINE2(newlstat, const char __user *, filename, + struct stat __user *, statbuf) +{ + struct kstat stat; + int error; + + error = vfs_lstat(filename, &stat); + if (error) + return error; + + return cp_new_stat(&stat, statbuf); +} + +#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) +SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename, + struct stat __user *, statbuf, int, flag) +{ + struct kstat stat; + int error; + + error = vfs_fstatat(dfd, filename, &stat, flag); + if (error) + return error; + return cp_new_stat(&stat, statbuf); +} +#endif + +SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf) +{ + struct kstat stat; + int error = vfs_fstat(fd, &stat); + + if (!error) + error = cp_new_stat(&stat, statbuf); + + return error; +} +#endif + +static int do_readlinkat(int dfd, const char __user *pathname, + char __user *buf, int bufsiz) +{ + struct path path; + int error; + int empty = 0; + unsigned int lookup_flags = LOOKUP_EMPTY; + + if (bufsiz <= 0) + return -EINVAL; + +retry: + error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty); + if (!error) { + struct inode *inode = d_backing_inode(path.dentry); + + error = empty ? -ENOENT : -EINVAL; + /* + * 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 = vfs_readlink(path.dentry, buf, bufsiz); + } + } + path_put(&path); + if (retry_estale(error, lookup_flags)) { + lookup_flags |= LOOKUP_REVAL; + goto retry; + } + } + return error; +} + +SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, + char __user *, buf, int, bufsiz) +{ + return do_readlinkat(dfd, pathname, buf, bufsiz); +} + +SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf, + int, bufsiz) +{ + return do_readlinkat(AT_FDCWD, path, buf, bufsiz); +} + + +/* ---------- LFS-64 ----------- */ +#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64) + +#ifndef INIT_STRUCT_STAT64_PADDING +# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st)) +#endif + +static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) +{ + struct stat64 tmp; + + INIT_STRUCT_STAT64_PADDING(tmp); +#ifdef CONFIG_MIPS + /* mips has weird padding, so we don't get 64 bits there */ + tmp.st_dev = new_encode_dev(stat->dev); + tmp.st_rdev = new_encode_dev(stat->rdev); +#else + tmp.st_dev = huge_encode_dev(stat->dev); + tmp.st_rdev = huge_encode_dev(stat->rdev); +#endif + tmp.st_ino = stat->ino; + if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) + return -EOVERFLOW; +#ifdef STAT64_HAS_BROKEN_ST_INO + tmp.__st_ino = stat->ino; +#endif + tmp.st_mode = stat->mode; + tmp.st_nlink = stat->nlink; + tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid); + tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid); + tmp.st_atime = stat->atime.tv_sec; + tmp.st_atime_nsec = stat->atime.tv_nsec; + tmp.st_mtime = stat->mtime.tv_sec; + tmp.st_mtime_nsec = stat->mtime.tv_nsec; + tmp.st_ctime = stat->ctime.tv_sec; + tmp.st_ctime_nsec = stat->ctime.tv_nsec; + tmp.st_size = stat->size; + tmp.st_blocks = stat->blocks; + tmp.st_blksize = stat->blksize; + return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; +} + +SYSCALL_DEFINE2(stat64, const char __user *, filename, + struct stat64 __user *, statbuf) +{ + struct kstat stat; + int error = vfs_stat(filename, &stat); + + if (!error) + error = cp_new_stat64(&stat, statbuf); + + return error; +} + +SYSCALL_DEFINE2(lstat64, const char __user *, filename, + struct stat64 __user *, statbuf) +{ + struct kstat stat; + int error = vfs_lstat(filename, &stat); + + if (!error) + error = cp_new_stat64(&stat, statbuf); + + return error; +} + +SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf) +{ + struct kstat stat; + int error = vfs_fstat(fd, &stat); + + if (!error) + error = cp_new_stat64(&stat, statbuf); + + return error; +} + +SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename, + struct stat64 __user *, statbuf, int, flag) +{ + struct kstat stat; + int error; + + error = vfs_fstatat(dfd, filename, &stat, flag); + if (error) + return error; + return cp_new_stat64(&stat, statbuf); +} +#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)); + + /* STATX_CHANGE_COOKIE is kernel-only for now */ + tmp.stx_mask = stat->result_mask & ~STATX_CHANGE_COOKIE; + tmp.stx_blksize = stat->blksize; + /* STATX_ATTR_CHANGE_MONOTONIC is kernel-only for now */ + tmp.stx_attributes = stat->attributes & ~STATX_ATTR_CHANGE_MONOTONIC; + 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); + tmp.stx_mnt_id = stat->mnt_id; + tmp.stx_dio_mem_align = stat->dio_mem_align; + tmp.stx_dio_offset_align = stat->dio_offset_align; + + return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0; +} + +int do_statx(int dfd, struct filename *filename, unsigned int 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; + + /* STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests + * from userland. + */ + mask &= ~STATX_CHANGE_COOKIE; + + error = vfs_statx(dfd, filename, flags, &stat, mask); + if (error) + return error; + + return cp_statx(&stat, buffer); +} + +/** + * sys_statx - System call to get enhanced stats + * @dfd: Base directory to pathwalk from *or* fd to stat. + * @filename: File to stat or "" with AT_EMPTY_PATH + * @flags: AT_* flags to control pathwalk. + * @mask: Parts of statx struct actually required. + * @buffer: Result buffer. + * + * Note that fstat() can be emulated by setting dfd to the fd of interest, + * supplying "" as the filename and setting AT_EMPTY_PATH in the flags. + */ +SYSCALL_DEFINE5(statx, + int, dfd, const char __user *, filename, unsigned, flags, + unsigned int, mask, + struct statx __user *, buffer) +{ + int ret; + struct filename *name; + + name = getname_flags(filename, getname_statx_lookup_flags(flags), NULL); + ret = do_statx(dfd, name, flags, mask, buffer); + putname(name); + + return ret; +} + +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT) +static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf) +{ + struct compat_stat tmp; + + if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev)) + return -EOVERFLOW; + if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev)) + return -EOVERFLOW; + + memset(&tmp, 0, sizeof(tmp)); + tmp.st_dev = new_encode_dev(stat->dev); + tmp.st_ino = stat->ino; + if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) + return -EOVERFLOW; + tmp.st_mode = stat->mode; + tmp.st_nlink = stat->nlink; + if (tmp.st_nlink != stat->nlink) + return -EOVERFLOW; + SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); + SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); + tmp.st_rdev = new_encode_dev(stat->rdev); + if ((u64) stat->size > MAX_NON_LFS) + return -EOVERFLOW; + tmp.st_size = stat->size; + tmp.st_atime = stat->atime.tv_sec; + tmp.st_atime_nsec = stat->atime.tv_nsec; + tmp.st_mtime = stat->mtime.tv_sec; + tmp.st_mtime_nsec = stat->mtime.tv_nsec; + tmp.st_ctime = stat->ctime.tv_sec; + tmp.st_ctime_nsec = stat->ctime.tv_nsec; + tmp.st_blocks = stat->blocks; + tmp.st_blksize = stat->blksize; + return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0; +} + +COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename, + struct compat_stat __user *, statbuf) +{ + struct kstat stat; + int error; + + error = vfs_stat(filename, &stat); + if (error) + return error; + return cp_compat_stat(&stat, statbuf); +} + +COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename, + struct compat_stat __user *, statbuf) +{ + struct kstat stat; + int error; + + error = vfs_lstat(filename, &stat); + if (error) + return error; + return cp_compat_stat(&stat, statbuf); +} + +#ifndef __ARCH_WANT_STAT64 +COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd, + const char __user *, filename, + struct compat_stat __user *, statbuf, int, flag) +{ + struct kstat stat; + int error; + + error = vfs_fstatat(dfd, filename, &stat, flag); + if (error) + return error; + return cp_compat_stat(&stat, statbuf); +} +#endif + +COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd, + struct compat_stat __user *, statbuf) +{ + struct kstat stat; + int error = vfs_fstat(fd, &stat); + + if (!error) + error = cp_compat_stat(&stat, statbuf); + return error; +} +#endif + +/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */ +void __inode_add_bytes(struct inode *inode, loff_t bytes) +{ + inode->i_blocks += bytes >> 9; + bytes &= 511; + inode->i_bytes += bytes; + if (inode->i_bytes >= 512) { + inode->i_blocks++; + inode->i_bytes -= 512; + } +} +EXPORT_SYMBOL(__inode_add_bytes); + +void inode_add_bytes(struct inode *inode, loff_t bytes) +{ + spin_lock(&inode->i_lock); + __inode_add_bytes(inode, bytes); + spin_unlock(&inode->i_lock); +} + +EXPORT_SYMBOL(inode_add_bytes); + +void __inode_sub_bytes(struct inode *inode, loff_t bytes) +{ + inode->i_blocks -= bytes >> 9; + bytes &= 511; + if (inode->i_bytes < bytes) { + inode->i_blocks--; + inode->i_bytes += 512; + } + inode->i_bytes -= bytes; +} + +EXPORT_SYMBOL(__inode_sub_bytes); + +void inode_sub_bytes(struct inode *inode, loff_t bytes) +{ + spin_lock(&inode->i_lock); + __inode_sub_bytes(inode, bytes); + spin_unlock(&inode->i_lock); +} + +EXPORT_SYMBOL(inode_sub_bytes); + +loff_t inode_get_bytes(struct inode *inode) +{ + loff_t ret; + + spin_lock(&inode->i_lock); + ret = __inode_get_bytes(inode); + spin_unlock(&inode->i_lock); + return ret; +} + +EXPORT_SYMBOL(inode_get_bytes); + +void inode_set_bytes(struct inode *inode, loff_t bytes) +{ + /* Caller is here responsible for sufficient locking + * (ie. inode->i_lock) */ + inode->i_blocks = bytes >> 9; + inode->i_bytes = bytes & 511; +} + +EXPORT_SYMBOL(inode_set_bytes); |