/fs/stat.c
https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t · C · 471 lines · 380 code · 76 blank · 15 comment · 55 complexity · 3de8b008e09908711bebbc840d5d5878 MD5 · raw file
- /*
- * linux/fs/stat.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- */
- #include <linux/module.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/syscalls.h>
- #include <linux/pagemap.h>
- #include <asm/uaccess.h>
- #include <asm/unistd.h>
- void generic_fillattr(struct inode *inode, struct kstat *stat)
- {
- stat->dev = inode->i_sb->s_dev;
- stat->ino = inode->i_ino;
- stat->mode = inode->i_mode;
- stat->nlink = inode->i_nlink;
- stat->uid = inode->i_uid;
- stat->gid = inode->i_gid;
- stat->rdev = inode->i_rdev;
- stat->size = i_size_read(inode);
- stat->atime = inode->i_atime;
- stat->mtime = inode->i_mtime;
- stat->ctime = inode->i_ctime;
- stat->blksize = (1 << inode->i_blkbits);
- stat->blocks = inode->i_blocks;
- }
- EXPORT_SYMBOL(generic_fillattr);
- int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
- {
- struct inode *inode = dentry->d_inode;
- int retval;
- retval = security_inode_getattr(mnt, dentry);
- if (retval)
- return retval;
- if (inode->i_op->getattr)
- return inode->i_op->getattr(mnt, dentry, stat);
- generic_fillattr(inode, stat);
- return 0;
- }
- EXPORT_SYMBOL(vfs_getattr);
- int vfs_fstat(unsigned int fd, struct kstat *stat)
- {
- struct file *f = fget(fd);
- int error = -EBADF;
- if (f) {
- error = vfs_getattr(f->f_path.mnt, f->f_path.dentry, stat);
- fput(f);
- }
- return error;
- }
- EXPORT_SYMBOL(vfs_fstat);
- int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
- int flag)
- {
- struct path path;
- int error = -EINVAL;
- int lookup_flags = 0;
- if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
- AT_EMPTY_PATH)) != 0)
- goto out;
- if (!(flag & AT_SYMLINK_NOFOLLOW))
- lookup_flags |= LOOKUP_FOLLOW;
- if (flag & AT_EMPTY_PATH)
- lookup_flags |= LOOKUP_EMPTY;
- error = user_path_at(dfd, filename, lookup_flags, &path);
- if (error)
- goto out;
- error = vfs_getattr(path.mnt, path.dentry, stat);
- path_put(&path);
- 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);
- #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, stat->uid);
- SET_GID(tmp.st_gid, 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 */
- static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
- {
- struct stat tmp;
- #if BITS_PER_LONG == 32
- if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
- return -EOVERFLOW;
- #else
- if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
- return -EOVERFLOW;
- #endif
- memset(&tmp, 0, sizeof(tmp));
- #if BITS_PER_LONG == 32
- tmp.st_dev = old_encode_dev(stat->dev);
- #else
- tmp.st_dev = new_encode_dev(stat->dev);
- #endif
- 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, stat->uid);
- SET_GID(tmp.st_gid, stat->gid);
- #if BITS_PER_LONG == 32
- tmp.st_rdev = old_encode_dev(stat->rdev);
- #else
- tmp.st_rdev = new_encode_dev(stat->rdev);
- #endif
- #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;
- #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;
- }
- SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
- char __user *, buf, int, bufsiz)
- {
- struct path path;
- int error;
- int empty = 0;
- if (bufsiz <= 0)
- return -EINVAL;
- error = user_path_at_empty(dfd, pathname, LOOKUP_EMPTY, &path, &empty);
- if (!error) {
- struct inode *inode = path.dentry->d_inode;
- error = empty ? -ENOENT : -EINVAL;
- if (inode->i_op->readlink) {
- error = security_inode_readlink(path.dentry);
- if (!error) {
- touch_atime(path.mnt, path.dentry);
- error = inode->i_op->readlink(path.dentry,
- buf, bufsiz);
- }
- }
- path_put(&path);
- }
- return error;
- }
- SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
- int, bufsiz)
- {
- return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
- }
- /* ---------- LFS-64 ----------- */
- #ifdef __ARCH_WANT_STAT64
- static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
- {
- struct stat64 tmp;
- memset(&tmp, 0, sizeof(struct stat64));
- #ifdef CONFIG_MIPS
- /* mips has weird padding, so we don't get 64 bits there */
- if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
- return -EOVERFLOW;
- 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 = stat->uid;
- tmp.st_gid = 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 */
- /* 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;
- }
- }
- 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)
- {
- spin_lock(&inode->i_lock);
- inode->i_blocks -= bytes >> 9;
- bytes &= 511;
- if (inode->i_bytes < bytes) {
- inode->i_blocks--;
- inode->i_bytes += 512;
- }
- inode->i_bytes -= 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 = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
- 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);