ffs_vnops: Simplify extattr access
As suggested in r167010, use the structure type and macros to access and modify UFS2 extended attributes. Add assertions that pointers are aligned in places where we now access the data through a structure pointer, instead of character-by-character. PR: 216127 Reported by: dewayne at heuristicsystems.com.au Reviewed by: kib@ Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D9225
This commit is contained in:
Conrad Meyer
parent
280ffa5ed7
commit
675c187cc4
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=312416
@ -100,6 +100,9 @@ __FBSDID("$FreeBSD$");
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#include "opt_directio.h"
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#include "opt_ffs.h"
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#define ALIGNED_TO(ptr, s) \
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(((uintptr_t)(ptr) & (_Alignof(s) - 1)) == 0)
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#ifdef DIRECTIO
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extern int ffs_rawread(struct vnode *vp, struct uio *uio, int *workdone);
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#endif
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@ -1100,46 +1103,30 @@ ffs_extwrite(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *ucred)
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* the length of the EA, and possibly the pointer to the entry and to the data.
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*/
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static int
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ffs_findextattr(u_char *ptr, u_int length, int nspace, const char *name, u_char **eap, u_char **eac)
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ffs_findextattr(u_char *ptr, u_int length, int nspace, const char *name,
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struct extattr **eapp, u_char **eac)
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{
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u_char *p, *pe, *pn, *p0;
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int eapad1, eapad2, ealength, ealen, nlen;
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uint32_t ul;
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struct extattr *eap, *eaend;
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size_t nlen;
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pe = ptr + length;
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nlen = strlen(name);
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for (p = ptr; p < pe; p = pn) {
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p0 = p;
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bcopy(p, &ul, sizeof(ul));
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pn = p + ul;
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KASSERT(ALIGNED_TO(ptr, struct extattr), ("unaligned"));
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eap = (struct extattr *)ptr;
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eaend = (struct extattr *)(ptr + length);
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for (; eap < eaend; eap = EXTATTR_NEXT(eap)) {
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/* make sure this entry is complete */
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if (pn > pe)
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if (EXTATTR_NEXT(eap) > eaend)
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break;
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p += sizeof(uint32_t);
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if (*p != nspace)
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if (eap->ea_namespace != nspace || eap->ea_namelength != nlen
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|| memcmp(eap->ea_name, name, nlen) != 0)
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continue;
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p++;
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eapad2 = *p++;
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if (*p != nlen)
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continue;
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p++;
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if (bcmp(p, name, nlen))
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continue;
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ealength = sizeof(uint32_t) + 3 + nlen;
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eapad1 = 8 - (ealength % 8);
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if (eapad1 == 8)
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eapad1 = 0;
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ealength += eapad1;
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ealen = ul - ealength - eapad2;
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p += nlen + eapad1;
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if (eap != NULL)
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*eap = p0;
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if (eapp != NULL)
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*eapp = eap;
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if (eac != NULL)
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*eac = p;
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return (ealen);
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*eac = EXTATTR_CONTENT(eap);
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return (EXTATTR_CONTENT_SIZE(eap));
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}
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return(-1);
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return (-1);
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}
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static int
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@ -1380,9 +1367,11 @@ vop_deleteextattr {
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{
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struct inode *ip;
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struct fs *fs;
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uint32_t ealength, ul;
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int ealen, olen, eapad1, eapad2, error, i, easize;
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u_char *eae, *p;
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struct extattr *eap;
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uint32_t ul;
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int olen, error, i, easize;
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u_char *eae;
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void *tmp;
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ip = VTOI(ap->a_vp);
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fs = ITOFS(ip);
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@ -1413,39 +1402,30 @@ vop_deleteextattr {
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if (error)
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return (error);
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ealength = eapad1 = ealen = eapad2 = 0;
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/* CEM: delete could be done in-place instead */
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eae = malloc(ip->i_ea_len, M_TEMP, M_WAITOK);
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bcopy(ip->i_ea_area, eae, ip->i_ea_len);
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easize = ip->i_ea_len;
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olen = ffs_findextattr(eae, easize, ap->a_attrnamespace, ap->a_name,
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&p, NULL);
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&eap, NULL);
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if (olen == -1) {
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/* delete but nonexistent */
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free(eae, M_TEMP);
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ffs_close_ea(ap->a_vp, 0, ap->a_cred, ap->a_td);
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return(ENOATTR);
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return (ENOATTR);
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}
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bcopy(p, &ul, sizeof ul);
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i = p - eae + ul;
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if (ul != ealength) {
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bcopy(p + ul, p + ealength, easize - i);
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easize += (ealength - ul);
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}
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if (easize > NXADDR * fs->fs_bsize) {
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free(eae, M_TEMP);
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ffs_close_ea(ap->a_vp, 0, ap->a_cred, ap->a_td);
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if (ip->i_ea_area != NULL && ip->i_ea_error == 0)
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ip->i_ea_error = ENOSPC;
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return(ENOSPC);
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}
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p = ip->i_ea_area;
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ul = eap->ea_length;
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i = (u_char *)EXTATTR_NEXT(eap) - eae;
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bcopy(EXTATTR_NEXT(eap), eap, easize - i);
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easize -= ul;
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tmp = ip->i_ea_area;
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ip->i_ea_area = eae;
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ip->i_ea_len = easize;
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free(p, M_TEMP);
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free(tmp, M_TEMP);
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error = ffs_close_ea(ap->a_vp, 1, ap->a_cred, ap->a_td);
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return(error);
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return (error);
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}
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/*
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@ -1499,7 +1479,7 @@ vop_getextattr {
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error = ENOATTR;
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ffs_close_ea(ap->a_vp, 0, ap->a_cred, ap->a_td);
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return(error);
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return (error);
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}
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/*
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@ -1519,9 +1499,7 @@ vop_listextattr {
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*/
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{
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struct inode *ip;
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u_char *eae, *p, *pe, *pn;
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unsigned easize;
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uint32_t ul;
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struct extattr *eap, *eaend;
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int error, ealen;
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ip = VTOI(ap->a_vp);
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@ -1537,31 +1515,31 @@ vop_listextattr {
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error = ffs_open_ea(ap->a_vp, ap->a_cred, ap->a_td);
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if (error)
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return (error);
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eae = ip->i_ea_area;
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easize = ip->i_ea_len;
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error = 0;
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if (ap->a_size != NULL)
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*ap->a_size = 0;
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pe = eae + easize;
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for(p = eae; error == 0 && p < pe; p = pn) {
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bcopy(p, &ul, sizeof(ul));
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pn = p + ul;
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if (pn > pe)
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KASSERT(ALIGNED_TO(ip->i_ea_area, struct extattr), ("unaligned"));
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eap = (struct extattr *)ip->i_ea_area;
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eaend = (struct extattr *)(ip->i_ea_area + ip->i_ea_len);
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for (; error == 0 && eap < eaend; eap = EXTATTR_NEXT(eap)) {
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/* make sure this entry is complete */
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if (EXTATTR_NEXT(eap) > eaend)
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break;
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p += sizeof(ul);
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if (*p++ != ap->a_attrnamespace)
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if (eap->ea_namespace != ap->a_attrnamespace)
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continue;
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p++; /* pad2 */
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ealen = *p;
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if (ap->a_size != NULL) {
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ealen = eap->ea_namelength;
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if (ap->a_size != NULL)
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*ap->a_size += ealen + 1;
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} else if (ap->a_uio != NULL) {
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error = uiomove(p, ealen + 1, ap->a_uio);
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}
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else if (ap->a_uio != NULL)
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error = uiomove(&eap->ea_namelength, ealen + 1,
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ap->a_uio);
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}
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ffs_close_ea(ap->a_vp, 0, ap->a_cred, ap->a_td);
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return(error);
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return (error);
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}
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/*
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@ -1582,10 +1560,12 @@ vop_setextattr {
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{
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struct inode *ip;
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struct fs *fs;
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struct extattr *eap;
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uint32_t ealength, ul;
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ssize_t ealen;
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int olen, eapad1, eapad2, error, i, easize;
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u_char *eae, *p;
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u_char *eae;
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void *tmp;
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ip = VTOI(ap->a_vp);
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fs = ITOFS(ip);
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@ -1625,29 +1605,33 @@ vop_setextattr {
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return (error);
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ealength = sizeof(uint32_t) + 3 + strlen(ap->a_name);
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eapad1 = 8 - (ealength % 8);
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if (eapad1 == 8)
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eapad1 = 0;
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eapad2 = 8 - (ealen % 8);
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if (eapad2 == 8)
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eapad2 = 0;
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eapad1 = roundup2(ealength, 8) - ealength;
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eapad2 = roundup2(ealen, 8) - ealen;
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ealength += eapad1 + ealen + eapad2;
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/*
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* CEM: rewrites of the same size or smaller could be done in-place
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* instead. (We don't acquire any fine-grained locks in here either,
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* so we could also do bigger writes in-place.)
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*/
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eae = malloc(ip->i_ea_len + ealength, M_TEMP, M_WAITOK);
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bcopy(ip->i_ea_area, eae, ip->i_ea_len);
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easize = ip->i_ea_len;
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olen = ffs_findextattr(eae, easize,
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ap->a_attrnamespace, ap->a_name, &p, NULL);
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olen = ffs_findextattr(eae, easize, ap->a_attrnamespace, ap->a_name,
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&eap, NULL);
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if (olen == -1) {
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/* new, append at end */
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p = eae + easize;
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KASSERT(ALIGNED_TO(eae + easize, struct extattr),
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("unaligned"));
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eap = (struct extattr *)(eae + easize);
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easize += ealength;
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} else {
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bcopy(p, &ul, sizeof ul);
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i = p - eae + ul;
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ul = eap->ea_length;
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i = (u_char *)EXTATTR_NEXT(eap) - eae;
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if (ul != ealength) {
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bcopy(p + ul, p + ealength, easize - i);
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bcopy(EXTATTR_NEXT(eap), (u_char *)eap + ealength,
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easize - i);
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easize += (ealength - ul);
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}
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}
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@ -1656,34 +1640,30 @@ vop_setextattr {
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ffs_close_ea(ap->a_vp, 0, ap->a_cred, ap->a_td);
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if (ip->i_ea_area != NULL && ip->i_ea_error == 0)
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ip->i_ea_error = ENOSPC;
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return(ENOSPC);
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return (ENOSPC);
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}
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bcopy(&ealength, p, sizeof(ealength));
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p += sizeof(ealength);
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*p++ = ap->a_attrnamespace;
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*p++ = eapad2;
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*p++ = strlen(ap->a_name);
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strcpy(p, ap->a_name);
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p += strlen(ap->a_name);
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bzero(p, eapad1);
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p += eapad1;
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error = uiomove(p, ealen, ap->a_uio);
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eap->ea_length = ealength;
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eap->ea_namespace = ap->a_attrnamespace;
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eap->ea_contentpadlen = eapad2;
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eap->ea_namelength = strlen(ap->a_name);
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memcpy(eap->ea_name, ap->a_name, strlen(ap->a_name));
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bzero(&eap->ea_name[strlen(ap->a_name)], eapad1);
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error = uiomove(EXTATTR_CONTENT(eap), ealen, ap->a_uio);
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if (error) {
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free(eae, M_TEMP);
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ffs_close_ea(ap->a_vp, 0, ap->a_cred, ap->a_td);
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if (ip->i_ea_area != NULL && ip->i_ea_error == 0)
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ip->i_ea_error = error;
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return(error);
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return (error);
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}
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p += ealen;
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bzero(p, eapad2);
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bzero((u_char *)EXTATTR_CONTENT(eap) + ealen, eapad2);
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p = ip->i_ea_area;
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tmp = ip->i_ea_area;
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ip->i_ea_area = eae;
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ip->i_ea_len = easize;
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free(p, M_TEMP);
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free(tmp, M_TEMP);
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error = ffs_close_ea(ap->a_vp, 1, ap->a_cred, ap->a_td);
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return(error);
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return (error);
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}
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/*
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