Author: rmacklem
Date: Wed Jul 22 23:33:37 2020
New Revision: 363437
URL: https://svnweb.freebsd.org/changeset/base/363437
Log:
Modify writing to mirrored pNFS DSs to prepare for use of ext_pgs mbufs.
This patch modifies writing to mirrored pNFS DSs slightly so that there is
only one m_copym() call for a mirrored pair instead of two of them.
This call replaces the custom nfsm_copym() call, which is no longer needed
and deleted by this patch. The patch does introduce a new nfsm_split()
function that only calls m_split() for the non-ext_pgs case.
The semantics of nfsm_uiombuflist() is changed to include code that nul
pads the generated mbuf list. This was done by nfsm_copym() prior to this
patch.
The main reason for this change is that it allows the data to be a list
of ext_pgs mbufs, since the m_copym() is for the entire mbuf list.
This support will be added in a future commit.
This patch only affects writing to mirrored flexible file layout pNFS servers.
Modified:
head/sys/fs/nfsclient/nfs_clcomsubs.c
head/sys/fs/nfsclient/nfs_clrpcops.c
Modified: head/sys/fs/nfsclient/nfs_clcomsubs.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clcomsubs.c Wed Jul 22 22:51:14 2020
(r363436)
+++ head/sys/fs/nfsclient/nfs_clcomsubs.c Wed Jul 22 23:33:37 2020
(r363437)
@@ -164,9 +164,9 @@ nfsm_uiombuflist(struct uio *uiop, int siz, struct mbu
{
char *uiocp;
struct mbuf *mp, *mp2, *firstmp;
- int xfer, left, mlen;
+ int i, left, mlen, rem, xfer;
int uiosiz, clflg;
- char *tcp;
+ char *mcp, *tcp;
KASSERT(uiop->uio_iovcnt == 1, ("nfsm_uiotombuf: iovcnt != 1"));
@@ -179,7 +179,9 @@ nfsm_uiombuflist(struct uio *uiop, int siz, struct mbu
else
NFSMGET(mp);
mp->m_len = 0;
+ mcp = mtod(mp, char *);
firstmp = mp2 = mp;
+ rem = NFSM_RNDUP(siz) - siz;
while (siz > 0) {
left = uiop->uio_iov->iov_len;
uiocp = uiop->uio_iov->iov_base;
@@ -194,18 +196,18 @@ nfsm_uiombuflist(struct uio *uiop, int siz, struct mbu
else
NFSMGET(mp);
mp->m_len = 0;
+ mcp = mtod(mp, char *);
mp2->m_next = mp;
mp2 = mp;
mlen = M_TRAILINGSPACE(mp);
}
xfer = (left > mlen) ? mlen : left;
if (uiop->uio_segflg == UIO_SYSSPACE)
- NFSBCOPY(uiocp, mtod(mp, caddr_t) +
- mp->m_len, xfer);
+ NFSBCOPY(uiocp, mcp, xfer);
else
- copyin(uiocp, mtod(mp, caddr_t) +
- mp->m_len, xfer);
+ copyin(uiocp, mcp, xfer);
mp->m_len += xfer;
+ mcp += xfer;
left -= xfer;
uiocp += xfer;
uiop->uio_offset += xfer;
@@ -216,6 +218,13 @@ nfsm_uiombuflist(struct uio *uiop, int siz, struct mbu
uiop->uio_iov->iov_base = (void *)tcp;
uiop->uio_iov->iov_len -= uiosiz;
siz -= uiosiz;
+ }
+ if (rem > 0) {
+ KASSERT(rem <= M_TRAILINGSPACE(mp),
+ ("nfsm_uiombuflist: no space for padding"));
+ for (i = 0; i < rem; i++)
+ *mcp++ = '\0';
+ mp->m_len += rem;
}
if (cpp != NULL)
*cpp = mtod(mp, caddr_t) + mp->m_len;
Modified: head/sys/fs/nfsclient/nfs_clrpcops.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clrpcops.c Wed Jul 22 22:51:14 2020
(r363436)
+++ head/sys/fs/nfsclient/nfs_clrpcops.c Wed Jul 22 23:33:37 2020
(r363437)
@@ -158,7 +158,6 @@ static int nfscl_dofflayoutio(vnode_t, struct uio *, i
nfsv4stateid_t *, int, struct nfscldevinfo *, struct nfscllayout *,
struct nfsclflayout *, uint64_t, uint64_t, int, int, struct mbuf *,
struct nfsclwritedsdorpc *, struct ucred *, NFSPROC_T *);
-static struct mbuf *nfsm_copym(struct mbuf *, int, int);
static int nfsrpc_readds(vnode_t, struct uio *, nfsv4stateid_t *, int *,
struct nfsclds *, uint64_t, int, struct nfsfh *, int, int, int,
struct ucred *, NFSPROC_T *);
@@ -220,6 +219,7 @@ static int nfsrpc_copyrpc(vnode_t, off_t, vnode_t, off
struct nfsvattr *, int *, bool, int *, struct ucred *, NFSPROC_T *);
static int nfsrpc_seekrpc(vnode_t, off_t *, nfsv4stateid_t *, bool *,
int, struct nfsvattr *, int *, struct ucred *);
+static struct mbuf *nfsm_split(struct mbuf *, uint64_t);
int nfs_pnfsio(task_fn_t *, void *);
@@ -5756,7 +5756,7 @@ nfscl_doiods(vnode_t vp, struct uio *uiop, int *iomode
struct nfscllayout *layp;
struct nfscldevinfo *dip;
struct nfsclflayout *rflp;
- struct mbuf *m;
+ struct mbuf *m, *m2;
struct nfsclwritedsdorpc *drpc, *tdrpc;
nfsv4stateid_t stateid;
struct ucred *newcred;
@@ -5870,6 +5870,13 @@ nfscl_doiods(vnode_t vp, struct uio *uiop, int *iomode
}
}
for (i = firstmirror; i < mirrorcnt && error == 0; i++){
+ m2 = NULL;
+ if (m != NULL && i < mirrorcnt - 1)
+ m2 = m_copym(m, 0, M_COPYALL, M_WAITOK);
+ else {
+ m2 = m;
+ m = NULL;
+ }
if ((layp->nfsly_flags & NFSLY_FLEXFILE) != 0) {
dev = rflp->nfsfl_ffm[i].dev;
dip = nfscl_getdevinfo(nmp->nm_clp, dev,
@@ -5886,7 +5893,7 @@ nfscl_doiods(vnode_t vp, struct uio *uiop, int *iomode
uiop, iomode, must_commit,
&eof, &stateid, rwaccess,
dip, layp, rflp, off, xfer,
- i, docommit, m, tdrpc,
+ i, docommit, m2, tdrpc,
newcred, p);
else
error = nfscl_doflayoutio(vp,
@@ -5895,8 +5902,11 @@ nfscl_doiods(vnode_t vp, struct uio *uiop, int *iomode
dip, layp, rflp, off, xfer,
docommit, newcred, p);
nfscl_reldevinfo(dip);
- } else
+ } else {
+ if (m2 != NULL)
+ m_freem(m2);
error = EIO;
+ }
tdrpc++;
}
if (m != NULL)
@@ -5962,38 +5972,6 @@ nfscl_doiods(vnode_t vp, struct uio *uiop, int *iomode
}
/*
- * Make a copy of the mbuf chain and add an mbuf for null padding, as required.
- */
-static struct mbuf *
-nfsm_copym(struct mbuf *m, int off, int xfer)
-{
- struct mbuf *m2, *m3, *m4;
- uint32_t *tl;
- int rem;
-
- m2 = m_copym(m, off, xfer, M_WAITOK);
- rem = NFSM_RNDUP(xfer) - xfer;
- if (rem > 0) {
- /*
- * The zero padding to a multiple of 4 bytes is required by
- * the XDR. So that the mbufs copied by reference aren't
- * modified, add an mbuf with the zero'd bytes to the list.
- * rem will be a maximum of 3, so one zero'd uint32_t is
- * sufficient.
- */
- m3 = m2;
- while (m3->m_next != NULL)
- m3 = m3->m_next;
- NFSMGET(m4);
- tl = mtod(m4, uint32_t *);
- *tl = 0;
- m4->m_len = rem;
- m3->m_next = m4;
- }
- return (m2);
-}
-
-/*
* Find a file layout that will handle the first bytes of the requested
* range and return the information from it needed to the I/O operation.
*/
@@ -6148,17 +6126,17 @@ nfscl_dofflayoutio(vnode_t vp, struct uio *uiop, int *
uint64_t len, int mirror, int docommit, struct mbuf *mp,
struct nfsclwritedsdorpc *drpc, struct ucred *cred, NFSPROC_T *p)
{
- uint64_t transfer, xfer;
- int error, rel_off;
+ uint64_t xfer;
+ int error;
struct nfsnode *np;
struct nfsfh *fhp;
struct nfsclds **dspp;
struct ucred *tcred;
- struct mbuf *m;
+ struct mbuf *m, *m2;
+ uint32_t copylen;
np = VTONFS(vp);
error = 0;
- rel_off = 0;
NFSCL_DEBUG(4, "nfscl_dofflayoutio: off=%ju len=%ju\n", (uintmax_t)off,
(uintmax_t)len);
/* Loop around, doing I/O for each stripe unit. */
@@ -6176,14 +6154,31 @@ nfscl_dofflayoutio(vnode_t vp, struct uio *uiop, int *
} else
tcred = cred;
if (rwflag == NFSV4OPEN_ACCESSREAD)
- transfer = dp->nfsdi_rsize;
- else
- transfer = dp->nfsdi_wsize;
+ copylen = dp->nfsdi_rsize;
+ else {
+ copylen = dp->nfsdi_wsize;
+ if (len > copylen && mp != NULL) {
+ /*
+ * When a mirrored configuration needs to do
+ * multiple writes to each mirror, all writes
+ * except the last one must be a multiple of
+ * 4 bytes. This is required so that the XDR
+ * does not need padding.
+ * If possible, clip the size to an exact
+ * multiple of the mbuf length, so that the
+ * split will be on an mbuf boundary.
+ */
+ copylen &= 0xfffffffc;
+ if (copylen > mp->m_len)
+ copylen = copylen / mp->m_len *
+ mp->m_len;
+ }
+ }
NFSLOCKNODE(np);
np->n_flag |= NDSCOMMIT;
NFSUNLOCKNODE(np);
- if (len > transfer && docommit == 0)
- xfer = transfer;
+ if (len > copylen && docommit == 0)
+ xfer = copylen;
else
xfer = len;
if (docommit != 0) {
@@ -6244,31 +6239,41 @@ nfscl_dofflayoutio(vnode_t vp, struct uio *uiop, int *
NFSUNLOCKCLSTATE();
}
} else {
- m = nfsm_copym(mp, rel_off, xfer);
- NFSCL_DEBUG(4, "mcopy reloff=%d xfer=%jd\n",
- rel_off, (uintmax_t)xfer);
+ m = mp;
+ if (xfer < len) {
+ /* The mbuf list must be split. */
+ m2 = nfsm_split(mp, xfer);
+ if (m2 != NULL)
+ mp = m2;
+ else {
+ m_freem(mp);
+ error = EIO;
+ }
+ }
+ NFSCL_DEBUG(4, "mcopy len=%jd xfer=%jd\n",
+ (uintmax_t)len, (uintmax_t)xfer);
/*
- * Do the writes after the first loop iteration
- * and the write for the last mirror via this
+ * Do last write to a mirrored DS with this
* thread.
- * This loop only iterates for small values
- * of nfsdi_wsize, which may never occur in
- * practice. However, the drpc is completely
- * used by the first iteration and, as such,
- * cannot be used after that.
*/
- if (mirror < flp->nfsfl_mirrorcnt - 1 &&
- rel_off == 0)
- error = nfsio_writedsmir(vp, iomode,
- must_commit, stateidp, *dspp, off,
- xfer, fhp, m, dp->nfsdi_vers,
- dp->nfsdi_minorvers, drpc, tcred,
- p);
- else
- error = nfsrpc_writedsmir(vp, iomode,
- must_commit, stateidp, *dspp, off,
- xfer, fhp, m, dp->nfsdi_vers,
- dp->nfsdi_minorvers, tcred, p);
+ if (error == 0) {
+ if (mirror < flp->nfsfl_mirrorcnt - 1)
+ error = nfsio_writedsmir(vp,
+ iomode, must_commit,
+ stateidp, *dspp, off,
+ xfer, fhp, m,
+ dp->nfsdi_vers,
+ dp->nfsdi_minorvers, drpc,
+ tcred, p);
+ else
+ error = nfsrpc_writedsmir(vp,
+ iomode, must_commit,
+ stateidp, *dspp, off,
+ xfer, fhp, m,
+ dp->nfsdi_vers,
+ dp->nfsdi_minorvers, tcred,
+ p);
+ }
NFSCL_DEBUG(4, "nfsio_writedsmir=%d\n", error);
if (error != 0 && error != EACCES && error !=
ESTALE) {
@@ -6283,7 +6288,6 @@ nfscl_dofflayoutio(vnode_t vp, struct uio *uiop, int *
if (error == 0) {
len -= xfer;
off += xfer;
- rel_off += xfer;
}
if ((dp->nfsdi_flags & NFSDI_TIGHTCOUPLED) == 0)
NFSFREECRED(tcred);
@@ -8615,3 +8619,14 @@ nfsmout:
return (error);
}
+/*
+ * Split an mbuf list. For non-M_EXTPG mbufs, just use m_split().
+ */
+static struct mbuf *
+nfsm_split(struct mbuf *mp, uint64_t xfer)
+{
+ struct mbuf *m;
+
+ m = m_split(mp, xfer, M_WAITOK);
+ return (m);
+}
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