Fix found places where uio_resid is truncated to int.

Add the sysctl debug.iosize_max_clamp, enabled by default. Setting the
sysctl to zero allows to perform the SSIZE_MAX-sized i/o requests from
the usermode.

Discussed with:	bde, das (previous versions)
MFC after:	1 month

9 files changed, 25 insertions, 19 deletions

diff --git a/sys/fs/cd9660/cd9660_vnops.c b/sys/fs/cd9660/cd9660_vnops.c
index 5f4780f..9a6ecc2 100644
--- a/sys/fs/cd9660/cd9660_vnops.c
+++ b/sys/fs/cd9660/cd9660_vnops.c
@@ -318,7 +318,7 @@ cd9660_read(ap)
 	do {
 		lbn = lblkno(imp, uio->uio_offset);
 		on = blkoff(imp, uio->uio_offset);
-		n = min((u_int)(imp->logical_block_size - on),
+		n = MIN((u_int)(imp->logical_block_size - on),
 			uio->uio_resid);
 		diff = (off_t)ip->i_size - uio->uio_offset;
 		if (diff <= 0)
@@ -343,7 +343,7 @@ cd9660_read(ap)
 			} else
 				error = bread(vp, lbn, size, NOCRED, &bp);
 		}
-		n = min(n, size - bp->b_resid);
+		n = MIN(n, size - bp->b_resid);
 		if (error) {
 			brelse(bp);
 			return (error);
diff --git a/sys/fs/devfs/devfs_vnops.c b/sys/fs/devfs/devfs_vnops.c
index 408c981..4a58a42 100644
--- a/sys/fs/devfs/devfs_vnops.c
+++ b/sys/fs/devfs/devfs_vnops.c
@@ -1156,7 +1156,8 @@ static int
 devfs_read_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td)
 {
 	struct cdev *dev;
-	int ioflag, error, ref, resid;
+	int ioflag, error, ref;
+	ssize_t resid;
 	struct cdevsw *dsw;
 	struct file *fpop;
 
@@ -1634,7 +1635,8 @@ static int
 devfs_write_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td)
 {
 	struct cdev *dev;
-	int error, ioflag, ref, resid;
+	int error, ioflag, ref;
+	ssize_t resid;
 	struct cdevsw *dsw;
 	struct file *fpop;
 
diff --git a/sys/fs/ext2fs/ext2_lookup.c b/sys/fs/ext2fs/ext2_lookup.c
index 194cd35..35ab631 100644
--- a/sys/fs/ext2fs/ext2_lookup.c
+++ b/sys/fs/ext2fs/ext2_lookup.c
@@ -1001,7 +1001,8 @@ ext2_dirempty(ip, parentino, cred)
 	off_t off;
 	struct dirtemplate dbuf;
 	struct ext2fs_direct_2 *dp = (struct ext2fs_direct_2 *)&dbuf;
-	int error, count, namlen;
+	int error, namlen;
+	ssize_t count;
 #define	MINDIRSIZ (sizeof(struct dirtemplate) / 2)
 
 	for (off = 0; off < ip->i_size; off += dp->e2d_reclen) {
diff --git a/sys/fs/msdosfs/msdosfs_vnops.c b/sys/fs/msdosfs/msdosfs_vnops.c
index 600aa0f..2c0920d 100644
--- a/sys/fs/msdosfs/msdosfs_vnops.c
+++ b/sys/fs/msdosfs/msdosfs_vnops.c
@@ -543,7 +543,7 @@ msdosfs_read(ap)
 	int error = 0;
 	int blsize;
 	int isadir;
-	int orig_resid;
+	ssize_t orig_resid;
 	u_int n;
 	u_long diff;
 	u_long on;
@@ -643,7 +643,7 @@ msdosfs_write(ap)
 {
 	int n;
 	int croffset;
-	int resid;
+	ssize_t resid;
 	u_long osize;
 	int error = 0;
 	u_long count;
diff --git a/sys/fs/nfsclient/nfs_clbio.c b/sys/fs/nfsclient/nfs_clbio.c
index 82a3692..d63862e 100644
--- a/sys/fs/nfsclient/nfs_clbio.c
+++ b/sys/fs/nfsclient/nfs_clbio.c
@@ -570,7 +570,7 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
 
 		n = 0;
 		if (on < bcount)
-			n = min((unsigned)(bcount - on), uio->uio_resid);
+			n = MIN((unsigned)(bcount - on), uio->uio_resid);
 		break;
 	    case VLNK:
 		NFSINCRGLOBAL(newnfsstats.biocache_readlinks);
@@ -589,7 +589,7 @@ ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
 			return (error);
 		    }
 		}
-		n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
+		n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
 		on = 0;
 		break;
 	    case VDIR:
@@ -757,8 +757,8 @@ nfs_directio_write(vp, uiop, cred, ioflag)
 		struct iovec iov;
 do_sync:
 		while (uiop->uio_resid > 0) {
-			size = min(uiop->uio_resid, wsize);
-			size = min(uiop->uio_iov->iov_len, size);
+			size = MIN(uiop->uio_resid, wsize);
+			size = MIN(uiop->uio_iov->iov_len, size);
 			iov.iov_base = uiop->uio_iov->iov_base;
 			iov.iov_len = size;
 			uio.uio_iov = &iov;
@@ -806,8 +806,8 @@ do_sync:
 		 * in NFS directio access.
 		 */
 		while (uiop->uio_resid > 0) {
-			size = min(uiop->uio_resid, wsize);
-			size = min(uiop->uio_iov->iov_len, size);
+			size = MIN(uiop->uio_resid, wsize);
+			size = MIN(uiop->uio_iov->iov_len, size);
 			bp = getpbuf(&ncl_pbuf_freecnt);
 			t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK);
 			t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK);
@@ -1023,7 +1023,7 @@ flush_and_restart:
 		NFSINCRGLOBAL(newnfsstats.biocache_writes);
 		lbn = uio->uio_offset / biosize;
 		on = uio->uio_offset & (biosize-1);
-		n = min((unsigned)(biosize - on), uio->uio_resid);
+		n = MIN((unsigned)(biosize - on), uio->uio_resid);
 again:
 		/*
 		 * Handle direct append and file extension cases, calculate
@@ -1572,7 +1572,7 @@ ncl_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td,
 			 * writes, but that is not possible any longer.
 			 */
 			int nread = bp->b_bcount - uiop->uio_resid;
-			int left  = uiop->uio_resid;
+			ssize_t left = uiop->uio_resid;
 
 			if (left > 0)
 				bzero((char *)bp->b_data + nread, left);
diff --git a/sys/fs/nfsclient/nfs_clvnops.c b/sys/fs/nfsclient/nfs_clvnops.c
index c842c19..f92d193 100644
--- a/sys/fs/nfsclient/nfs_clvnops.c
+++ b/sys/fs/nfsclient/nfs_clvnops.c
@@ -2177,7 +2177,8 @@ nfs_readdir(struct vop_readdir_args *ap)
 	struct vnode *vp = ap->a_vp;
 	struct nfsnode *np = VTONFS(vp);
 	struct uio *uio = ap->a_uio;
-	int tresid, error = 0;
+	ssize_t tresid;
+	int error = 0;
 	struct vattr vattr;
 	
 	if (vp->v_type != VDIR) 
diff --git a/sys/fs/nfsserver/nfs_nfsdstate.c b/sys/fs/nfsserver/nfs_nfsdstate.c
index f14ad43..f44917e 100644
--- a/sys/fs/nfsserver/nfs_nfsdstate.c
+++ b/sys/fs/nfsserver/nfs_nfsdstate.c
@@ -3962,7 +3962,7 @@ nfsrv_setupstable(NFSPROC_T *p)
 	struct nfst_rec *tsp;
 	int error, i, tryagain;
 	off_t off = 0;
-	int aresid, len;
+	ssize_t aresid, len;
 	struct timeval curtime;
 
 	/*
diff --git a/sys/fs/pseudofs/pseudofs_vnops.c b/sys/fs/pseudofs/pseudofs_vnops.c
index a81d7aa..8a9ca64 100644
--- a/sys/fs/pseudofs/pseudofs_vnops.c
+++ b/sys/fs/pseudofs/pseudofs_vnops.c
@@ -589,7 +589,8 @@ pfs_read(struct vop_read_args *va)
 	struct proc *proc;
 	struct sbuf *sb = NULL;
 	int error, locked;
-	unsigned int buflen, offset, resid;
+	off_t offset;
+	ssize_t buflen, resid;
 
 	PFS_TRACE(("%s", pn->pn_name));
 	pfs_assert_not_owned(pn);
diff --git a/sys/fs/udf/udf_vnops.c b/sys/fs/udf/udf_vnops.c
index b8e39b3..7a99fcb 100644
--- a/sys/fs/udf/udf_vnops.c
+++ b/sys/fs/udf/udf_vnops.c
@@ -439,8 +439,9 @@ udf_read(struct vop_read_args *ap)
 	uint8_t *data;
 	daddr_t lbn, rablock;
 	off_t diff, fsize;
+	ssize_t n;
 	int error = 0;
-	long size, n, on;
+	long size, on;
 
 	if (uio->uio_resid == 0)
 		return (0);