diff options
Diffstat (limited to 'sys/kern/vfs_vnops.c')
| -rw-r--r-- | sys/kern/vfs_vnops.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c index 1cd6c99bc4ff..9a6f87a362b1 100644 --- a/sys/kern/vfs_vnops.c +++ b/sys/kern/vfs_vnops.c @@ -335,6 +335,45 @@ vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) } /* + * Package up an I/O request on a vnode into a uio and do it. The I/O + * request is split up into smaller chunks and we try to avoid saturating + * the buffer cache while potentially holding a vnode locked, so we + * check bwillwrite() before calling vn_rdwr() + */ +int +vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) + enum uio_rw rw; + struct vnode *vp; + caddr_t base; + int len; + off_t offset; + enum uio_seg segflg; + int ioflg; + struct ucred *cred; + int *aresid; + struct proc *p; +{ + int error = 0; + + do { + int chunk = (len > MAXBSIZE) ? MAXBSIZE : len; + + if (rw != UIO_READ && vp->v_type == VREG) + bwillwrite(); + error = vn_rdwr(rw, vp, base, chunk, offset, segflg, + ioflg, cred, aresid, p); + len -= chunk; /* aresid calc already includes length */ + if (error) + break; + offset += chunk; + base += chunk; + } while (len); + if (aresid) + *aresid += len; + return (error); +} + +/* * File table vnode read routine. */ static int |