diff options
Diffstat (limited to 'fs/stat.c')
| -rw-r--r-- | fs/stat.c | 334 |
1 files changed, 187 insertions, 147 deletions
diff --git a/fs/stat.c b/fs/stat.c index 9cf41f719d5..ae0c3cef992 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -4,7 +4,7 @@ * Copyright (C) 1991, 1992 Linus Torvalds */ -#include <linux/module.h> +#include <linux/export.h> #include <linux/mm.h> #include <linux/errno.h> #include <linux/file.h> @@ -27,87 +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->blocks = inode->i_blocks; 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) +/** + * 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); return 0; } +EXPORT_SYMBOL(vfs_getattr_nosec); + +int vfs_getattr(struct path *path, struct kstat *stat) +{ + int retval; + + retval = security_inode_getattr(path->mnt, path->dentry); + if (retval) + return retval; + return vfs_getattr_nosec(path, stat); +} + EXPORT_SYMBOL(vfs_getattr); -int vfs_stat_fd(int dfd, 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_walk_fd(dfd, name, LOOKUP_FOLLOW, &nd); - if (!error) { - error = vfs_getattr(nd.path.mnt, nd.path.dentry, stat); - path_put(&nd.path); + if (f.file) { + error = vfs_getattr(&f.file->f_path, stat); + fdput(f); } return error; } +EXPORT_SYMBOL(vfs_fstat); -int vfs_stat(char __user *name, struct kstat *stat) +int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, + int flag) { - return vfs_stat_fd(AT_FDCWD, name, stat); -} + struct path path; + int error = -EINVAL; + unsigned int lookup_flags = 0; -EXPORT_SYMBOL(vfs_stat); + if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | + AT_EMPTY_PATH)) != 0) + goto out; -int vfs_lstat_fd(int dfd, char __user *name, struct kstat *stat) -{ - struct nameidata nd; - int error; + 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 = __user_walk_fd(dfd, name, 0, &nd); - if (!error) { - error = vfs_getattr(nd.path.mnt, nd.path.dentry, stat); - path_put(&nd.path); + 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_lstat(char __user *name, struct kstat *stat) +int vfs_stat(const char __user *name, struct kstat *stat) { - return vfs_lstat_fd(AT_FDCWD, name, stat); + return vfs_fstatat(AT_FDCWD, name, stat, 0); } +EXPORT_SYMBOL(vfs_stat); -EXPORT_SYMBOL(vfs_lstat); - -int vfs_fstat(unsigned int fd, struct kstat *stat) +int vfs_lstat(const char __user *name, 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; + return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW); } +EXPORT_SYMBOL(vfs_lstat); -EXPORT_SYMBOL(vfs_fstat); #ifdef __ARCH_WANT_OLD_STAT @@ -138,8 +160,8 @@ static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * sta 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) @@ -152,27 +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_fd(AT_FDCWD, 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_fd(AT_FDCWD, 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); @@ -185,24 +213,32 @@ 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; @@ -210,17 +246,9 @@ static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) 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; @@ -235,52 +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_fd(AT_FDCWD, filename, &stat); - - if (!error) - error = cp_new_stat(&stat, statbuf); + int error = vfs_stat(filename, &stat); - 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_fd(AT_FDCWD, 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); } #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) -asmlinkage long sys_newfstatat(int dfd, char __user *filename, - struct stat __user *statbuf, int flag) +SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename, + struct stat __user *, statbuf, int, flag) { struct kstat stat; - int error = -EINVAL; - - if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) - goto out; - - if (flag & AT_SYMLINK_NOFOLLOW) - error = vfs_lstat_fd(dfd, filename, &stat); - else - error = vfs_stat_fd(dfd, filename, &stat); - - if (!error) - error = cp_new_stat(&stat, statbuf); + int error; -out: - return error; + error = vfs_fstatat(dfd, filename, &stat, flag); + if (error) + return error; + return cp_new_stat(&stat, statbuf); } #endif -asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf) +SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf) { struct kstat stat; int error = vfs_fstat(fd, &stat); @@ -291,48 +312,59 @@ asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf) return error; } -asmlinkage long sys_readlinkat(int dfd, 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_walk_fd(dfd, path, 0, &nd); +retry: + error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty); if (!error) { - struct inode *inode = nd.path.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.path.dentry); + error = empty ? -ENOENT : -EINVAL; + if (inode->i_op->readlink) { + error = security_inode_readlink(path.dentry); if (!error) { - touch_atime(nd.path.mnt, nd.path.dentry); - error = inode->i_op->readlink(nd.path.dentry, + touch_atime(&path); + error = inode->i_op->readlink(path.dentry, buf, bufsiz); } } - path_put(&nd.path); + path_put(&path); + if (retry_estale(error, lookup_flags)) { + lookup_flags |= LOOKUP_REVAL; + goto retry; + } } return error; } -asmlinkage long sys_readlink(const char __user *path, char __user *buf, - int bufsiz) +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)) @@ -351,8 +383,8 @@ static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) #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; @@ -365,7 +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); @@ -375,7 +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); @@ -385,7 +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); @@ -396,31 +432,22 @@ asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user * statbuf) return error; } -asmlinkage long sys_fstatat64(int dfd, char __user *filename, - struct stat64 __user *statbuf, int flag) +SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename, + struct stat64 __user *, statbuf, int, flag) { struct kstat stat; - int error = -EINVAL; - - if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) - goto out; - - if (flag & AT_SYMLINK_NOFOLLOW) - error = vfs_lstat_fd(dfd, filename, &stat); - else - error = vfs_stat_fd(dfd, filename, &stat); - - if (!error) - error = cp_new_stat64(&stat, statbuf); + int error; -out: - return error; + error = vfs_fstatat(dfd, filename, &stat, flag); + if (error) + return error; + return cp_new_stat64(&stat, statbuf); } -#endif /* __ARCH_WANT_STAT64 */ +#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */ -void inode_add_bytes(struct inode *inode, loff_t bytes) +/* 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; @@ -428,14 +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) { @@ -443,6 +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); } |