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| author | Konstantin Belousov <kib@FreeBSD.org> | 2024-01-01 22:22:44 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2024-01-11 16:46:53 +0000 |
| commit | cbf323cf503b69516ef19542c4630c0d42d74b05 (patch) | |
| tree | 8f4c5d564407705bc78f7fcb2e4812c7e2f5c766 | |
| parent | 9e951d6b4b708fad9993aca0a1cede1c74d735e0 (diff) | |
| download | src-cbf323cf503b69516ef19542c4630c0d42d74b05.tar.gz src-cbf323cf503b69516ef19542c4630c0d42d74b05.zip | |
nfsclient: limit situations when we do unlocked read-ahead by nfsiod
(cherry picked from commit 70dc6b2ce314a0f32755005ad02802fca7ed186e)
| -rw-r--r-- | sys/fs/nfsclient/nfs_clbio.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/sys/fs/nfsclient/nfs_clbio.c b/sys/fs/nfsclient/nfs_clbio.c index 63e97f405198..7b9b68782d53 100644 --- a/sys/fs/nfsclient/nfs_clbio.c +++ b/sys/fs/nfsclient/nfs_clbio.c @@ -484,9 +484,14 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) on = uio->uio_offset - (lbn * biosize); /* - * Start the read ahead(s), as required. + * Start the read ahead(s), as required. Do not do + * read-ahead if there are writeable mappings, since + * unlocked read by nfsiod could obliterate changes + * done by userspace. */ - if (nmp->nm_readahead > 0) { + if (nmp->nm_readahead > 0 && + !vm_object_mightbedirty(vp->v_object) && + vp->v_object->un_pager.vnp.writemappings == 0) { for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) { rabn = lbn + 1 + nra; @@ -674,6 +679,8 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) */ NFSLOCKNODE(np); if (nmp->nm_readahead > 0 && + !vm_object_mightbedirty(vp->v_object) && + vp->v_object->un_pager.vnp.writemappings == 0 && (bp->b_flags & B_INVAL) == 0 && (np->n_direofoffset == 0 || (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && |