Date: Sat, 22 Feb 2020 20:50:30 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r358252 - in head/sys: fs/nfsclient sys Message-ID: <202002222050.01MKoUVV037218@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: kib Date: Sat Feb 22 20:50:30 2020 New Revision: 358252 URL: https://svnweb.freebsd.org/changeset/base/358252 Log: Fix NFS client deadlock when read reports truncated node. If node attribute returned in the reply for read rpc indicate truncation, and it happens that the vnode is exclusively locked, update of the node attributes would try to shrink vnode size. Since during the read some vnode pages were busied by the reading thread, vnode_pager_setsize() deadlocks waiting for the busy state owned by the caller. Use a thread-local flag to indicate that NFS read owns some (s)busy pages states and postpone the call to vnode_pager_setsize() until the thread relinguishes the ownership. Diagnosed by: rlibby Tested by: pho, rlibby Sponsored by: The FreeBSD Foundation MFC after: 1 week Modified: head/sys/fs/nfsclient/nfs_clbio.c head/sys/fs/nfsclient/nfs_clport.c head/sys/sys/proc.h Modified: head/sys/fs/nfsclient/nfs_clbio.c ============================================================================== --- head/sys/fs/nfsclient/nfs_clbio.c Sat Feb 22 20:43:04 2020 (r358251) +++ head/sys/fs/nfsclient/nfs_clbio.c Sat Feb 22 20:50:30 2020 (r358252) @@ -425,14 +425,11 @@ int ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) { struct nfsnode *np = VTONFS(vp); - int biosize, i; struct buf *bp, *rabp; struct thread *td; struct nfsmount *nmp = VFSTONFS(vp->v_mount); daddr_t lbn, rabn; - int bcount; - int seqcount; - int nra, error = 0, n = 0, on = 0; + int biosize, bcount, error, i, n, nra, on, save2, seqcount; off_t tmp_off; KASSERT(uio->uio_rw == UIO_READ, ("ncl_read mode")); @@ -464,6 +461,8 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int iof /* No caching/ no readaheads. Just read data into the user buffer */ return ncl_readrpc(vp, uio, cred); + n = 0; + on = 0; biosize = vp->v_bufobj.bo_bsize; seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); @@ -471,6 +470,7 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int iof if (error) return error; + save2 = curthread_pflags2_set(TDP2_SBPAGES); do { u_quad_t nsize; @@ -495,7 +495,9 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int iof rabp = nfs_getcacheblk(vp, rabn, biosize, td); if (!rabp) { error = newnfs_sigintr(nmp, td); - return (error ? error : EINTR); + if (error == 0) + error = EINTR; + goto out; } if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { rabp->b_flags |= B_ASYNC; @@ -526,7 +528,9 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int iof if (!bp) { error = newnfs_sigintr(nmp, td); - return (error ? error : EINTR); + if (error == 0) + error = EINTR; + goto out; } /* @@ -540,7 +544,7 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int iof error = ncl_doio(vp, bp, cred, td, 0); if (error) { brelse(bp); - return (error); + goto out; } } @@ -561,7 +565,9 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int iof bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); if (!bp) { error = newnfs_sigintr(nmp, td); - return (error ? error : EINTR); + if (error == 0) + error = EINTR; + goto out; } if ((bp->b_flags & B_CACHE) == 0) { bp->b_iocmd = BIO_READ; @@ -570,7 +576,7 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int iof if (error) { bp->b_ioflags |= BIO_ERROR; brelse(bp); - return (error); + goto out; } } n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); @@ -580,14 +586,17 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int iof NFSINCRGLOBAL(nfsstatsv1.biocache_readdirs); if (np->n_direofoffset && uio->uio_offset >= np->n_direofoffset) { - return (0); + error = 0; + goto out; } lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); if (!bp) { - error = newnfs_sigintr(nmp, td); - return (error ? error : EINTR); + error = newnfs_sigintr(nmp, td); + if (error == 0) + error = EINTR; + goto out; } if ((bp->b_flags & B_CACHE) == 0) { bp->b_iocmd = BIO_READ; @@ -612,12 +621,16 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int iof */ for (i = 0; i <= lbn && !error; i++) { if (np->n_direofoffset - && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) - return (0); + && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) { + error = 0; + goto out; + } bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td); if (!bp) { error = newnfs_sigintr(nmp, td); - return (error ? error : EINTR); + if (error == 0) + error = EINTR; + goto out; } if ((bp->b_flags & B_CACHE) == 0) { bp->b_iocmd = BIO_READ; @@ -646,7 +659,7 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int iof * we give up. */ if (error) - return (error); + goto out; } /* @@ -706,6 +719,12 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int iof if (bp != NULL) brelse(bp); } while (error == 0 && uio->uio_resid > 0 && n > 0); +out: + curthread_pflags2_restore(save2); + if ((curthread->td_pflags2 & TDP2_SBPAGES) == 0) { + NFSLOCKNODE(np); + ncl_pager_setsize(vp, NULL); + } return (error); } Modified: head/sys/fs/nfsclient/nfs_clport.c ============================================================================== --- head/sys/fs/nfsclient/nfs_clport.c Sat Feb 22 20:43:04 2020 (r358251) +++ head/sys/fs/nfsclient/nfs_clport.c Sat Feb 22 20:50:30 2020 (r358252) @@ -597,7 +597,8 @@ ncl_pager_setsize(struct vnode *vp, u_quad_t *nsizep) setnsize = false; if (object != NULL && nsize != object->un_pager.vnp.vnp_size) { - if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE) + if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE && + (curthread->td_pflags2 & TDP2_SBPAGES) == 0) setnsize = true; else np->n_flag |= NVNSETSZSKIP; Modified: head/sys/sys/proc.h ============================================================================== --- head/sys/sys/proc.h Sat Feb 22 20:43:04 2020 (r358251) +++ head/sys/sys/proc.h Sat Feb 22 20:50:30 2020 (r358252) @@ -515,6 +515,8 @@ do { \ #define TDP_EXECVMSPC 0x40000000 /* Execve destroyed old vmspace */ #define TDP_SIGFASTPENDING 0x80000000 /* Pending signal due to sigfastblock */ +#define TDP2_SBPAGES 0x00000001 /* Owns sbusy on some pages */ + /* * Reasons that the current thread can not be run yet. * More than one may apply.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202002222050.01MKoUVV037218>