/* * Set various file attributes. * N.B. After this call fhp needs an fh_put */ __be32 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, int check_guard, time_t guardtime) { struct dentry *dentry; struct inode *inode; int accmode = MAY_SATTR; int ftype = 0; int imode; __be32 err; int host_err; int size_change = 0; if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) accmode |= MAY_WRITE|MAY_OWNER_OVERRIDE; if (iap->ia_valid & ATTR_SIZE) ftype = S_IFREG; /* Get inode */ err = fh_verify(rqstp, fhp, ftype, accmode); if (err) goto out; dentry = fhp->fh_dentry; inode = dentry->d_inode; /* Ignore any mode updates on symlinks */ if (S_ISLNK(inode->i_mode)) iap->ia_valid &= ~ATTR_MODE; if (!iap->ia_valid) goto out; /* NFSv2 does not differentiate between "set-[ac]time-to-now" * which only requires access, and "set-[ac]time-to-X" which * requires ownership. * So if it looks like it might be "set both to the same time which * is close to now", and if inode_change_ok fails, then we * convert to "set to now" instead of "set to explicit time" * * We only call inode_change_ok as the last test as technically * it is not an interface that we should be using. It is only * valid if the filesystem does not define it's own i_op->setattr. */ #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) #define MAX_TOUCH_TIME_ERROR (30*60) if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET && iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec ) { /* Looks probable. Now just make sure time is in the right ballpark. * Solaris, at least, doesn't seem to care what the time request is. * We require it be within 30 minutes of now. */ time_t delta = iap->ia_atime.tv_sec - get_seconds(); if (delta<0) delta = -delta; if (delta < MAX_TOUCH_TIME_ERROR && inode_change_ok(inode, iap) != 0) { /* turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME * this will cause notify_change to set these times to "now" */ iap->ia_valid &= ~BOTH_TIME_SET; } } /* The size case is special. It changes the file as well as the attributes. */ if (iap->ia_valid & ATTR_SIZE) { if (iap->ia_size < inode->i_size) { err = nfsd_permission(fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE); if (err) goto out; } /* * If we are changing the size of the file, then * we need to break all leases. */ host_err = break_lease(inode, FMODE_WRITE | O_NONBLOCK); if (host_err == -EWOULDBLOCK) host_err = -ETIMEDOUT; if (host_err) /* ENOMEM or EWOULDBLOCK */ goto out_nfserr; host_err = get_write_access(inode); if (host_err) goto out_nfserr; size_change = 1; host_err = locks_verify_truncate(inode, NULL, iap->ia_size); if (host_err) { put_write_access(inode); goto out_nfserr; } DQUOT_INIT(inode); } imode = inode->i_mode; if (iap->ia_valid & ATTR_MODE) { iap->ia_mode &= S_IALLUGO; imode = iap->ia_mode |= (imode & ~S_IALLUGO); } /* Revoke setuid/setgid bit on chown/chgrp */ if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) iap->ia_valid |= ATTR_KILL_SUID; if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid) iap->ia_valid |= ATTR_KILL_SGID; /* Change the attributes. */ iap->ia_valid |= ATTR_CTIME; err = nfserr_notsync; if (!check_guard || guardtime == inode->i_ctime.tv_sec) { fh_lock(fhp); host_err = notify_change(dentry, iap); err = nfserrno(host_err); fh_unlock(fhp); } if (size_change) put_write_access(inode); if (!err) if (EX_ISSYNC(fhp->fh_export)) write_inode_now(inode, 1); out: return err; out_nfserr: err = nfserrno(host_err); goto out; }
static long do_sys_truncate(const char __user *pathname, loff_t length) { struct path path; struct inode *inode; int error; error = -EINVAL; if (length < 0) /* sorry, but loff_t says... */ goto out; error = user_path(pathname, &path); if (error) goto out; inode = path.dentry->d_inode; /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ error = -EISDIR; if (S_ISDIR(inode->i_mode)) goto dput_and_out; error = -EINVAL; if (!S_ISREG(inode->i_mode)) goto dput_and_out; error = mnt_want_write(path.mnt); if (error) goto dput_and_out; error = inode_permission(inode, MAY_WRITE); if (error) goto mnt_drop_write_and_out; error = -EPERM; if (IS_APPEND(inode)) goto mnt_drop_write_and_out; error = get_write_access(inode); if (error) goto mnt_drop_write_and_out; /* * Make sure that there are no leases. get_write_access() protects * against the truncate racing with a lease-granting setlease(). */ error = break_lease(inode, O_WRONLY); if (error) goto put_write_and_out; error = locks_verify_truncate(inode, NULL, length); if (!error) error = security_path_truncate(&path, length, 0); if (!error) error = do_truncate(path.dentry, length, 0, NULL); put_write_and_out: put_write_access(inode); mnt_drop_write_and_out: mnt_drop_write(path.mnt); dput_and_out: path_put(&path); out: return error; }
static long do_sys_truncate(const char __user * path, loff_t length) { struct nameidata nd; struct inode * inode; int error; error = -EINVAL; if (length < 0) /* sorry, but loff_t says... */ goto out; error = user_path_walk(path, &nd); if (error) goto out; inode = nd.path.dentry->d_inode; /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ error = -EISDIR; if (S_ISDIR(inode->i_mode)) goto dput_and_out; error = -EINVAL; if (!S_ISREG(inode->i_mode)) goto dput_and_out; error = mnt_want_write(nd.path.mnt); if (error) goto dput_and_out; error = vfs_permission(&nd, MAY_WRITE); if (error) goto mnt_drop_write_and_out; error = -EPERM; if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) goto mnt_drop_write_and_out; error = get_write_access(inode); if (error) goto mnt_drop_write_and_out; /* * Make sure that there are no leases. get_write_access() protects * against the truncate racing with a lease-granting setlease(). */ error = break_lease(inode, FMODE_WRITE); if (error) goto put_write_and_out; error = locks_verify_truncate(inode, NULL, length); if (!error) { DQUOT_INIT(inode); error = do_truncate(nd.path.dentry, length, 0, NULL); } put_write_and_out: put_write_access(inode); mnt_drop_write_and_out: mnt_drop_write(nd.path.mnt); dput_and_out: path_put(&nd.path); out: return error; }