diff options
Diffstat (limited to 'fs/stat.c')
| -rw-r--r-- | fs/stat.c | 331 |
1 files changed, 216 insertions, 115 deletions
diff --git a/fs/stat.c b/fs/stat.c index b8a0e5110ab..ae0c3cef992 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -4,17 +4,16 @@ * Copyright (C) 1991, 1992 Linus Torvalds */ -#include <linux/config.h> -#include <linux/module.h> +#include <linux/export.h> #include <linux/mm.h> #include <linux/errno.h> #include <linux/file.h> -#include <linux/smp_lock.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> @@ -28,84 +27,109 @@ void generic_fillattr(struct inode *inode, struct kstat *stat) 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->size = i_size_read(inode); + stat->blksize = (1 << inode->i_blkbits); stat->blocks = inode->i_blocks; - stat->blksize = inode->i_blksize; } EXPORT_SYMBOL(generic_fillattr); -int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) +/** + * vfs_getattr_nosec - getattr without security checks + * @path: file to get attributes from + * @stat: structure to return attributes in + * + * 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(struct path *path, struct kstat *stat) { - struct inode *inode = dentry->d_inode; - int retval; - - retval = security_inode_getattr(mnt, dentry); - if (retval) - return retval; + struct inode *inode = path->dentry->d_inode; if (inode->i_op->getattr) - return inode->i_op->getattr(mnt, dentry, stat); + return inode->i_op->getattr(path->mnt, path->dentry, stat); generic_fillattr(inode, stat); - if (!stat->blksize) { - struct super_block *s = inode->i_sb; - unsigned blocks; - blocks = (stat->size+s->s_blocksize-1) >> s->s_blocksize_bits; - stat->blocks = (s->s_blocksize / 512) * blocks; - stat->blksize = s->s_blocksize; - } return 0; } -EXPORT_SYMBOL(vfs_getattr); +EXPORT_SYMBOL(vfs_getattr_nosec); -int vfs_stat(char __user *name, struct kstat *stat) +int vfs_getattr(struct path *path, struct kstat *stat) { - struct nameidata nd; - int error; + int retval; - error = user_path_walk(name, &nd); - if (!error) { - error = vfs_getattr(nd.mnt, nd.dentry, stat); - path_release(&nd); - } - return error; + retval = security_inode_getattr(path->mnt, path->dentry); + if (retval) + return retval; + return vfs_getattr_nosec(path, stat); } -EXPORT_SYMBOL(vfs_stat); +EXPORT_SYMBOL(vfs_getattr); -int vfs_lstat(char __user *name, struct kstat *stat) +int vfs_fstat(unsigned int fd, struct kstat *stat) { - struct nameidata nd; - int error; + struct fd f = fdget_raw(fd); + int error = -EBADF; - error = user_path_walk_link(name, &nd); - if (!error) { - error = vfs_getattr(nd.mnt, nd.dentry, stat); - path_release(&nd); + if (f.file) { + error = vfs_getattr(&f.file->f_path, stat); + fdput(f); } return error; } +EXPORT_SYMBOL(vfs_fstat); -EXPORT_SYMBOL(vfs_lstat); - -int vfs_fstat(unsigned int fd, struct kstat *stat) +int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, + int flag) { - struct file *f = fget(fd); - int error = -EBADF; - - if (f) { - error = vfs_getattr(f->f_vfsmnt, f->f_dentry, stat); - fput(f); + struct path path; + int error = -EINVAL; + unsigned 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; +retry: + error = user_path_at(dfd, filename, lookup_flags, &path); + if (error) + goto out; + + error = vfs_getattr(&path, stat); + path_put(&path); + if (retry_estale(error, lookup_flags)) { + lookup_flags |= LOOKUP_REVAL; + goto 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_fstat); #ifdef __ARCH_WANT_OLD_STAT @@ -130,12 +154,14 @@ static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * sta 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); + 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) @@ -148,27 +174,33 @@ static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * sta return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; } -asmlinkage long sys_stat(char __user * filename, struct __old_kernel_stat __user * statbuf) +SYSCALL_DEFINE2(stat, const char __user *, filename, + struct __old_kernel_stat __user *, statbuf) { struct kstat stat; - int error = vfs_stat(filename, &stat); + int error; - if (!error) - error = cp_old_stat(&stat, statbuf); + error = vfs_stat(filename, &stat); + if (error) + return error; - return error; + return cp_old_stat(&stat, statbuf); } -asmlinkage long sys_lstat(char __user * filename, struct __old_kernel_stat __user * statbuf) + +SYSCALL_DEFINE2(lstat, const char __user *, filename, + struct __old_kernel_stat __user *, statbuf) { struct kstat stat; - int error = vfs_lstat(filename, &stat); + int error; - if (!error) - error = cp_old_stat(&stat, statbuf); + error = vfs_lstat(filename, &stat); + if (error) + return error; - return error; + return cp_old_stat(&stat, statbuf); } -asmlinkage long sys_fstat(unsigned int fd, struct __old_kernel_stat __user * statbuf) + +SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf) { struct kstat stat; int error = vfs_fstat(fd, &stat); @@ -181,40 +213,42 @@ asmlinkage long sys_fstat(unsigned int fd, struct __old_kernel_stat __user * sta #endif /* __ARCH_WANT_OLD_STAT */ +#if BITS_PER_LONG == 32 +# define choose_32_64(a,b) a +#else +# define choose_32_64(a,b) b +#endif + +#define valid_dev(x) choose_32_64(old_valid_dev,new_valid_dev)(x) +#define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x) + +#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 BITS_PER_LONG == 32 - if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev)) + if (!valid_dev(stat->dev) || !valid_dev(stat->rdev)) return -EOVERFLOW; -#else - if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) +#if BITS_PER_LONG == 32 + if (stat->size > MAX_NON_LFS) 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 + INIT_STRUCT_STAT_PADDING(tmp); + tmp.st_dev = 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); -#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 + 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 = encode_dev(stat->rdev); tmp.st_size = stat->size; tmp.st_atime = stat->atime.tv_sec; tmp.st_mtime = stat->mtime.tv_sec; @@ -229,27 +263,45 @@ static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; } -asmlinkage long sys_newstat(char __user * filename, struct stat __user * statbuf) +SYSCALL_DEFINE2(newstat, const char __user *, filename, + struct stat __user *, statbuf) { struct kstat stat; int error = vfs_stat(filename, &stat); - if (!error) - error = cp_new_stat(&stat, statbuf); - - return error; + if (error) + return error; + return cp_new_stat(&stat, statbuf); } -asmlinkage long sys_newlstat(char __user * filename, struct stat __user * statbuf) + +SYSCALL_DEFINE2(newlstat, const char __user *, filename, + struct stat __user *, statbuf) { struct kstat stat; - int error = vfs_lstat(filename, &stat); + int error; - if (!error) - error = cp_new_stat(&stat, statbuf); + error = vfs_lstat(filename, &stat); + if (error) + return error; - return error; + return cp_new_stat(&stat, statbuf); } -asmlinkage long sys_newfstat(unsigned int fd, struct stat __user * 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); @@ -260,40 +312,59 @@ asmlinkage long sys_newfstat(unsigned int fd, struct stat __user * statbuf) return error; } -asmlinkage long sys_readlink(const char __user * path, char __user * buf, int bufsiz) +SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, + char __user *, buf, int, bufsiz) { - struct nameidata nd; + struct path path; int error; + int empty = 0; + unsigned int lookup_flags = LOOKUP_EMPTY; if (bufsiz <= 0) return -EINVAL; - error = user_path_walk_link(path, &nd); +retry: + error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty); if (!error) { - struct inode * inode = nd.dentry->d_inode; + struct inode *inode = path.dentry->d_inode; - error = -EINVAL; - if (inode->i_op && inode->i_op->readlink) { - error = security_inode_readlink(nd.dentry); + error = empty ? -ENOENT : -EINVAL; + if (inode->i_op->readlink) { + error = security_inode_readlink(path.dentry); if (!error) { - touch_atime(nd.mnt, nd.dentry); - error = inode->i_op->readlink(nd.dentry, buf, bufsiz); + touch_atime(&path); + error = inode->i_op->readlink(path.dentry, + buf, bufsiz); } } - path_release(&nd); + path_put(&path); + if (retry_estale(error, lookup_flags)) { + lookup_flags |= LOOKUP_REVAL; + goto retry; + } } 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 +#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; - memset(&tmp, 0, sizeof(struct stat64)); + INIT_STRUCT_STAT64_PADDING(tmp); #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)) @@ -305,13 +376,15 @@ static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) 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_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; @@ -324,7 +397,8 @@ static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; } -asmlinkage long sys_stat64(char __user * filename, struct stat64 __user * statbuf) +SYSCALL_DEFINE2(stat64, const char __user *, filename, + struct stat64 __user *, statbuf) { struct kstat stat; int error = vfs_stat(filename, &stat); @@ -334,7 +408,9 @@ asmlinkage long sys_stat64(char __user * filename, struct stat64 __user * statbu return error; } -asmlinkage long sys_lstat64(char __user * filename, struct stat64 __user * statbuf) + +SYSCALL_DEFINE2(lstat64, const char __user *, filename, + struct stat64 __user *, statbuf) { struct kstat stat; int error = vfs_lstat(filename, &stat); @@ -344,7 +420,8 @@ asmlinkage long sys_lstat64(char __user * filename, struct stat64 __user * statb return error; } -asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user * statbuf) + +SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf) { struct kstat stat; int error = vfs_fstat(fd, &stat); @@ -355,11 +432,22 @@ asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user * statbuf) return error; } -#endif /* __ARCH_WANT_STAT64 */ +SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename, + struct stat64 __user *, statbuf, int, flag) +{ + struct kstat stat; + int error; -void inode_add_bytes(struct inode *inode, loff_t bytes) + 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 */ + +/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */ +void __inode_add_bytes(struct inode *inode, loff_t bytes) { - spin_lock(&inode->i_lock); inode->i_blocks += bytes >> 9; bytes &= 511; inode->i_bytes += bytes; @@ -367,14 +455,19 @@ void inode_add_bytes(struct inode *inode, loff_t bytes) 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) +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) { @@ -382,6 +475,14 @@ void inode_sub_bytes(struct inode *inode, loff_t bytes) 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); } |