forked from luck/tmp_suning_uos_patched
3ddcd0569c
The inode structure layout is largely random, and some of the vfs paths really do care. The path lookup in particular is already quite D$ intensive, and profiles show that accessing the 'inode->i_op->xyz' fields is quite costly. We already optimized the dcache to not unnecessarily load the d_op structure for members that are often NULL using the DCACHE_OP_xyz bits in dentry->d_flags, and this does something very similar for the inode ops that are used during pathname lookup. It also re-orders the fields so that the fields accessed by 'stat' are together at the beginning of the inode structure, and roughly in the order accessed. The effect of this seems to be in the 1-2% range for an empty kernel "make -j" run (which is fairly kernel-intensive, mostly in filename lookup), so it's visible. The numbers are fairly noisy, though, and likely depend a lot on exact microarchitecture. So there's more tuning to be done. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
473 lines
11 KiB
C
473 lines
11 KiB
C
/*
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* linux/fs/stat.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/errno.h>
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#include <linux/file.h>
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#include <linux/highuid.h>
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#include <linux/fs.h>
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#include <linux/namei.h>
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#include <linux/security.h>
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#include <linux/syscalls.h>
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#include <linux/pagemap.h>
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#include <asm/uaccess.h>
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#include <asm/unistd.h>
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void generic_fillattr(struct inode *inode, struct kstat *stat)
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{
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stat->dev = inode->i_sb->s_dev;
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stat->ino = inode->i_ino;
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stat->mode = inode->i_mode;
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stat->nlink = inode->i_nlink;
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stat->uid = inode->i_uid;
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stat->gid = inode->i_gid;
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stat->rdev = inode->i_rdev;
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stat->size = i_size_read(inode);
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stat->atime = inode->i_atime;
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stat->mtime = inode->i_mtime;
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stat->ctime = inode->i_ctime;
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stat->blksize = (1 << inode->i_blkbits);
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stat->blocks = inode->i_blocks;
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}
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EXPORT_SYMBOL(generic_fillattr);
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int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
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{
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struct inode *inode = dentry->d_inode;
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int retval;
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retval = security_inode_getattr(mnt, dentry);
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if (retval)
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return retval;
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if (inode->i_op->getattr)
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return inode->i_op->getattr(mnt, dentry, stat);
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generic_fillattr(inode, stat);
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return 0;
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}
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EXPORT_SYMBOL(vfs_getattr);
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int vfs_fstat(unsigned int fd, struct kstat *stat)
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{
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struct file *f = fget(fd);
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int error = -EBADF;
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if (f) {
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error = vfs_getattr(f->f_path.mnt, f->f_path.dentry, stat);
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fput(f);
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}
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return error;
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}
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EXPORT_SYMBOL(vfs_fstat);
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int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
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int flag)
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{
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struct path path;
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int error = -EINVAL;
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int lookup_flags = 0;
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if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
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AT_EMPTY_PATH)) != 0)
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goto out;
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if (!(flag & AT_SYMLINK_NOFOLLOW))
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lookup_flags |= LOOKUP_FOLLOW;
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if (flag & AT_NO_AUTOMOUNT)
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lookup_flags |= LOOKUP_NO_AUTOMOUNT;
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if (flag & AT_EMPTY_PATH)
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lookup_flags |= LOOKUP_EMPTY;
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error = user_path_at(dfd, filename, lookup_flags, &path);
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if (error)
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goto out;
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error = vfs_getattr(path.mnt, path.dentry, stat);
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path_put(&path);
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out:
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return error;
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}
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EXPORT_SYMBOL(vfs_fstatat);
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int vfs_stat(const char __user *name, struct kstat *stat)
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{
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return vfs_fstatat(AT_FDCWD, name, stat, 0);
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}
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EXPORT_SYMBOL(vfs_stat);
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int vfs_lstat(const char __user *name, struct kstat *stat)
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{
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return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
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}
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EXPORT_SYMBOL(vfs_lstat);
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#ifdef __ARCH_WANT_OLD_STAT
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/*
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* For backward compatibility? Maybe this should be moved
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* into arch/i386 instead?
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*/
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static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
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{
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static int warncount = 5;
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struct __old_kernel_stat tmp;
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if (warncount > 0) {
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warncount--;
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printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
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current->comm);
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} else if (warncount < 0) {
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/* it's laughable, but... */
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warncount = 0;
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}
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memset(&tmp, 0, sizeof(struct __old_kernel_stat));
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tmp.st_dev = old_encode_dev(stat->dev);
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tmp.st_ino = stat->ino;
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if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
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return -EOVERFLOW;
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tmp.st_mode = stat->mode;
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tmp.st_nlink = stat->nlink;
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if (tmp.st_nlink != stat->nlink)
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return -EOVERFLOW;
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SET_UID(tmp.st_uid, stat->uid);
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SET_GID(tmp.st_gid, stat->gid);
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tmp.st_rdev = old_encode_dev(stat->rdev);
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#if BITS_PER_LONG == 32
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if (stat->size > MAX_NON_LFS)
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return -EOVERFLOW;
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#endif
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tmp.st_size = stat->size;
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tmp.st_atime = stat->atime.tv_sec;
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tmp.st_mtime = stat->mtime.tv_sec;
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tmp.st_ctime = stat->ctime.tv_sec;
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return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
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}
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SYSCALL_DEFINE2(stat, const char __user *, filename,
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struct __old_kernel_stat __user *, statbuf)
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{
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struct kstat stat;
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int error;
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error = vfs_stat(filename, &stat);
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if (error)
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return error;
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return cp_old_stat(&stat, statbuf);
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}
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SYSCALL_DEFINE2(lstat, const char __user *, filename,
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struct __old_kernel_stat __user *, statbuf)
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{
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struct kstat stat;
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int error;
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error = vfs_lstat(filename, &stat);
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if (error)
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return error;
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return cp_old_stat(&stat, statbuf);
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}
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SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
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{
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struct kstat stat;
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int error = vfs_fstat(fd, &stat);
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if (!error)
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error = cp_old_stat(&stat, statbuf);
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return error;
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}
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#endif /* __ARCH_WANT_OLD_STAT */
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static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
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{
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struct stat tmp;
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#if BITS_PER_LONG == 32
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if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
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return -EOVERFLOW;
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#else
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if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
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return -EOVERFLOW;
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#endif
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memset(&tmp, 0, sizeof(tmp));
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#if BITS_PER_LONG == 32
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tmp.st_dev = old_encode_dev(stat->dev);
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#else
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tmp.st_dev = new_encode_dev(stat->dev);
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#endif
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tmp.st_ino = stat->ino;
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if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
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return -EOVERFLOW;
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tmp.st_mode = stat->mode;
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tmp.st_nlink = stat->nlink;
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if (tmp.st_nlink != stat->nlink)
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return -EOVERFLOW;
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SET_UID(tmp.st_uid, stat->uid);
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SET_GID(tmp.st_gid, stat->gid);
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#if BITS_PER_LONG == 32
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tmp.st_rdev = old_encode_dev(stat->rdev);
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#else
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tmp.st_rdev = new_encode_dev(stat->rdev);
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#endif
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#if BITS_PER_LONG == 32
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if (stat->size > MAX_NON_LFS)
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return -EOVERFLOW;
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#endif
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tmp.st_size = stat->size;
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tmp.st_atime = stat->atime.tv_sec;
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tmp.st_mtime = stat->mtime.tv_sec;
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tmp.st_ctime = stat->ctime.tv_sec;
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#ifdef STAT_HAVE_NSEC
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tmp.st_atime_nsec = stat->atime.tv_nsec;
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tmp.st_mtime_nsec = stat->mtime.tv_nsec;
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tmp.st_ctime_nsec = stat->ctime.tv_nsec;
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#endif
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tmp.st_blocks = stat->blocks;
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tmp.st_blksize = stat->blksize;
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return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
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}
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SYSCALL_DEFINE2(newstat, const char __user *, filename,
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struct stat __user *, statbuf)
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{
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struct kstat stat;
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int error = vfs_stat(filename, &stat);
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if (error)
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return error;
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return cp_new_stat(&stat, statbuf);
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}
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SYSCALL_DEFINE2(newlstat, const char __user *, filename,
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struct stat __user *, statbuf)
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{
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struct kstat stat;
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int error;
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error = vfs_lstat(filename, &stat);
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if (error)
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return error;
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return cp_new_stat(&stat, statbuf);
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}
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#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
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SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
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struct stat __user *, statbuf, int, flag)
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{
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struct kstat stat;
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int error;
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error = vfs_fstatat(dfd, filename, &stat, flag);
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if (error)
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return error;
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return cp_new_stat(&stat, statbuf);
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}
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#endif
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SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
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{
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struct kstat stat;
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int error = vfs_fstat(fd, &stat);
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if (!error)
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error = cp_new_stat(&stat, statbuf);
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return error;
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}
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SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
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char __user *, buf, int, bufsiz)
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{
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struct path path;
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int error;
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if (bufsiz <= 0)
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return -EINVAL;
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error = user_path_at(dfd, pathname, LOOKUP_EMPTY, &path);
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if (!error) {
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struct inode *inode = path.dentry->d_inode;
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error = -EINVAL;
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if (inode->i_op->readlink) {
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error = security_inode_readlink(path.dentry);
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if (!error) {
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touch_atime(path.mnt, path.dentry);
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error = inode->i_op->readlink(path.dentry,
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buf, bufsiz);
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}
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}
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path_put(&path);
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}
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return error;
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}
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SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
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int, bufsiz)
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{
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return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
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}
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/* ---------- LFS-64 ----------- */
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#ifdef __ARCH_WANT_STAT64
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static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
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{
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struct stat64 tmp;
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memset(&tmp, 0, sizeof(struct stat64));
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#ifdef CONFIG_MIPS
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/* mips has weird padding, so we don't get 64 bits there */
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if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
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return -EOVERFLOW;
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tmp.st_dev = new_encode_dev(stat->dev);
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tmp.st_rdev = new_encode_dev(stat->rdev);
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#else
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tmp.st_dev = huge_encode_dev(stat->dev);
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tmp.st_rdev = huge_encode_dev(stat->rdev);
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#endif
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tmp.st_ino = stat->ino;
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if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
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return -EOVERFLOW;
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#ifdef STAT64_HAS_BROKEN_ST_INO
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tmp.__st_ino = stat->ino;
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#endif
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tmp.st_mode = stat->mode;
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tmp.st_nlink = stat->nlink;
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tmp.st_uid = stat->uid;
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tmp.st_gid = stat->gid;
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tmp.st_atime = stat->atime.tv_sec;
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tmp.st_atime_nsec = stat->atime.tv_nsec;
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tmp.st_mtime = stat->mtime.tv_sec;
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tmp.st_mtime_nsec = stat->mtime.tv_nsec;
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tmp.st_ctime = stat->ctime.tv_sec;
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tmp.st_ctime_nsec = stat->ctime.tv_nsec;
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tmp.st_size = stat->size;
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tmp.st_blocks = stat->blocks;
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tmp.st_blksize = stat->blksize;
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return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
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}
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SYSCALL_DEFINE2(stat64, const char __user *, filename,
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struct stat64 __user *, statbuf)
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{
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struct kstat stat;
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int error = vfs_stat(filename, &stat);
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if (!error)
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error = cp_new_stat64(&stat, statbuf);
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return error;
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}
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SYSCALL_DEFINE2(lstat64, const char __user *, filename,
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struct stat64 __user *, statbuf)
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{
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struct kstat stat;
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int error = vfs_lstat(filename, &stat);
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if (!error)
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error = cp_new_stat64(&stat, statbuf);
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return error;
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}
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SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
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{
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struct kstat stat;
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int error = vfs_fstat(fd, &stat);
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if (!error)
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error = cp_new_stat64(&stat, statbuf);
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return error;
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}
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SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
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struct stat64 __user *, statbuf, int, flag)
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{
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struct kstat stat;
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int error;
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error = vfs_fstatat(dfd, filename, &stat, flag);
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if (error)
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return error;
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return cp_new_stat64(&stat, statbuf);
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}
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#endif /* __ARCH_WANT_STAT64 */
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/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
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void __inode_add_bytes(struct inode *inode, loff_t bytes)
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{
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inode->i_blocks += bytes >> 9;
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bytes &= 511;
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inode->i_bytes += bytes;
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if (inode->i_bytes >= 512) {
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inode->i_blocks++;
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inode->i_bytes -= 512;
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}
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}
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void inode_add_bytes(struct inode *inode, loff_t bytes)
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{
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spin_lock(&inode->i_lock);
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__inode_add_bytes(inode, bytes);
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spin_unlock(&inode->i_lock);
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}
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EXPORT_SYMBOL(inode_add_bytes);
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void inode_sub_bytes(struct inode *inode, loff_t bytes)
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{
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spin_lock(&inode->i_lock);
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inode->i_blocks -= bytes >> 9;
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bytes &= 511;
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if (inode->i_bytes < bytes) {
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inode->i_blocks--;
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inode->i_bytes += 512;
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}
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inode->i_bytes -= bytes;
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spin_unlock(&inode->i_lock);
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}
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EXPORT_SYMBOL(inode_sub_bytes);
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loff_t inode_get_bytes(struct inode *inode)
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{
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loff_t ret;
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spin_lock(&inode->i_lock);
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ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
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spin_unlock(&inode->i_lock);
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return ret;
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}
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EXPORT_SYMBOL(inode_get_bytes);
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void inode_set_bytes(struct inode *inode, loff_t bytes)
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{
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/* Caller is here responsible for sufficient locking
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* (ie. inode->i_lock) */
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inode->i_blocks = bytes >> 9;
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inode->i_bytes = bytes & 511;
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}
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EXPORT_SYMBOL(inode_set_bytes);
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