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Date:      Wed, 14 Dec 2011 22:04:15 +0000 (UTC)
From:      "Pedro F. Giffuni" <pfg@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r228507 - head/sys/fs/ext2fs
Message-ID:  <201112142204.pBEM4FfZ016569@svn.freebsd.org>

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Author: pfg
Date: Wed Dec 14 22:04:14 2011
New Revision: 228507
URL: http://svn.freebsd.org/changeset/base/228507

Log:
  Merge ext2_readwrite.c into ext2_vnops.c as done in UFS in r101729.
  
  This removes the obfuscations mentioned in ext2_readwrite and
  places the clustering funtion in a location similar to other
  UFS-based implementations.
  
  No performance or functional changeses are expected from
  this move.
  
  PR:		kern/159232
  Suggested by:	bde
  Approved by:	jhb (mentor)
  MFC after:	2 weeks

Deleted:
  head/sys/fs/ext2fs/ext2_readwrite.c
Modified:
  head/sys/fs/ext2fs/ext2_vnops.c

Modified: head/sys/fs/ext2fs/ext2_vnops.c
==============================================================================
--- head/sys/fs/ext2fs/ext2_vnops.c	Wed Dec 14 20:57:41 2011	(r228506)
+++ head/sys/fs/ext2fs/ext2_vnops.c	Wed Dec 14 22:04:14 2011	(r228507)
@@ -64,9 +64,13 @@
 #include <sys/file.h>
 
 #include <vm/vm.h>
+#include <vm/vm_page.h>
+#include <vm/vm_object.h>
 #include <vm/vm_extern.h>
 #include <vm/vnode_pager.h>
 
+#include "opt_directio.h"
+
 #include <fs/fifofs/fifo.h>
 
 #include <ufs/ufs/dir.h>
@@ -159,8 +163,6 @@ struct vop_vector ext2_fifoops = {
 	.vop_vptofh =		ext2_vptofh,
 };
 
-#include <fs/ext2fs/ext2_readwrite.c>
-
 /*
  * A virgin directory (no blushing please).
  * Note that the type and namlen fields are reversed relative to ext2.
@@ -1675,3 +1677,328 @@ bad:
 	vput(tvp);
 	return (error);
 }
+
+/*
+ * Vnode op for reading.
+ */
+static int
+ext2_read(ap)
+	struct vop_read_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	struct vnode *vp;
+	struct inode *ip;
+	struct uio *uio;
+	struct m_ext2fs *fs;
+	struct buf *bp;
+	daddr_t lbn, nextlbn;
+	off_t bytesinfile;
+	long size, xfersize, blkoffset;
+	int error, orig_resid, seqcount;
+	int ioflag;
+
+	vp = ap->a_vp;
+	uio = ap->a_uio;
+	ioflag = ap->a_ioflag;
+
+	seqcount = ap->a_ioflag >> IO_SEQSHIFT;
+	ip = VTOI(vp);
+
+#ifdef INVARIANTS
+	if (uio->uio_rw != UIO_READ)
+		panic("%s: mode", "ext2_read");
+
+	if (vp->v_type == VLNK) {
+		if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
+			panic("%s: short symlink", "ext2_read");
+	} else if (vp->v_type != VREG && vp->v_type != VDIR)
+		panic("%s: type %d", "ext2_read", vp->v_type);
+#endif
+	orig_resid = uio->uio_resid;
+	KASSERT(orig_resid >= 0, ("ext2_read: uio->uio_resid < 0"));
+	if (orig_resid == 0)
+		return (0);
+	KASSERT(uio->uio_offset >= 0, ("ext2_read: uio->uio_offset < 0"));
+	fs = ip->i_e2fs;
+	if (uio->uio_offset < ip->i_size &&
+	    uio->uio_offset >= fs->e2fs_maxfilesize)
+	    	return (EOVERFLOW);
+
+	for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
+		if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
+			break;
+		lbn = lblkno(fs, uio->uio_offset);
+		nextlbn = lbn + 1;
+		size = blksize(fs, ip, lbn);
+		blkoffset = blkoff(fs, uio->uio_offset);
+
+		xfersize = fs->e2fs_fsize - blkoffset;
+		if (uio->uio_resid < xfersize)
+			xfersize = uio->uio_resid;
+		if (bytesinfile < xfersize)
+			xfersize = bytesinfile;
+
+		if (lblktosize(fs, nextlbn) >= ip->i_size)
+			error = bread(vp, lbn, size, NOCRED, &bp);
+		else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0)
+			error = cluster_read(vp, ip->i_size, lbn, size,
+			    NOCRED, blkoffset + uio->uio_resid, seqcount, &bp);
+		else if (seqcount > 1) {
+			int nextsize = blksize(fs, ip, nextlbn);
+			error = breadn(vp, lbn,
+			    size, &nextlbn, &nextsize, 1, NOCRED, &bp);
+		} else
+			error = bread(vp, lbn, size, NOCRED, &bp);
+		if (error) {
+			brelse(bp);
+			bp = NULL;
+			break;
+		}
+
+		/*
+		 * If IO_DIRECT then set B_DIRECT for the buffer.  This
+		 * will cause us to attempt to release the buffer later on
+		 * and will cause the buffer cache to attempt to free the
+		 * underlying pages.
+		 */
+		if (ioflag & IO_DIRECT)
+			bp->b_flags |= B_DIRECT;
+
+		/*
+		 * We should only get non-zero b_resid when an I/O error
+		 * has occurred, which should cause us to break above.
+		 * However, if the short read did not cause an error,
+		 * then we want to ensure that we do not uiomove bad
+		 * or uninitialized data.
+		 */
+		size -= bp->b_resid;
+		if (size < xfersize) {
+			if (size == 0)
+				break;
+			xfersize = size;
+		}
+		error = uiomove((char *)bp->b_data + blkoffset,
+  			(int)xfersize, uio);
+		if (error)
+			break;
+
+		if (ioflag & (IO_VMIO|IO_DIRECT)) {
+			/*
+			 * If it's VMIO or direct I/O, then we don't
+			 * need the buf, mark it available for
+			 * freeing. If it's non-direct VMIO, the VM has
+			 * the data.
+			 */
+			bp->b_flags |= B_RELBUF;
+			brelse(bp);
+		} else {
+			/*
+			 * Otherwise let whoever
+			 * made the request take care of
+			 * freeing it. We just queue
+			 * it onto another list.
+			 */
+			bqrelse(bp);
+		}
+	}
+
+	/* 
+	 * This can only happen in the case of an error
+	 * because the loop above resets bp to NULL on each iteration
+	 * and on normal completion has not set a new value into it.
+	 * so it must have come from a 'break' statement
+	 */
+	if (bp != NULL) {
+		if (ioflag & (IO_VMIO|IO_DIRECT)) {
+			bp->b_flags |= B_RELBUF;
+			brelse(bp);
+		} else {
+			bqrelse(bp);
+		}
+	}
+
+	if ((error == 0 || uio->uio_resid != orig_resid) &&
+	    (vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
+		ip->i_flag |= IN_ACCESS;
+	return (error);
+}
+
+/*
+ * Vnode op for writing.
+ */
+static int
+ext2_write(ap)
+	struct vop_write_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	struct vnode *vp;
+	struct uio *uio;
+	struct inode *ip;
+	struct m_ext2fs *fs;
+	struct buf *bp;
+	daddr_t lbn;
+	off_t osize;
+	int blkoffset, error, flags, ioflag, resid, size, seqcount, xfersize;
+
+	ioflag = ap->a_ioflag;
+	uio = ap->a_uio;
+	vp = ap->a_vp;
+
+	seqcount = ioflag >> IO_SEQSHIFT;
+	ip = VTOI(vp);
+
+#ifdef INVARIANTS
+	if (uio->uio_rw != UIO_WRITE)
+		panic("%s: mode", "ext2_write");
+#endif
+
+	switch (vp->v_type) {
+	case VREG:
+		if (ioflag & IO_APPEND)
+			uio->uio_offset = ip->i_size;
+		if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
+			return (EPERM);
+		/* FALLTHROUGH */
+	case VLNK:
+		break;
+	case VDIR:
+		/* XXX differs from ffs -- this is called from ext2_mkdir(). */
+		if ((ioflag & IO_SYNC) == 0)
+		panic("ext2_write: nonsync dir write");
+		break;
+	default:
+		panic("ext2_write: type %p %d (%jd,%jd)", (void *)vp,
+		    vp->v_type, (intmax_t)uio->uio_offset,
+		    (intmax_t)uio->uio_resid);
+	}
+
+	KASSERT(uio->uio_resid >= 0, ("ext2_write: uio->uio_resid < 0"));
+	KASSERT(uio->uio_offset >= 0, ("ext2_write: uio->uio_offset < 0"));
+	fs = ip->i_e2fs;
+	if ((uoff_t)uio->uio_offset + uio->uio_resid > fs->e2fs_maxfilesize)
+		return (EFBIG);
+	/*
+	 * Maybe this should be above the vnode op call, but so long as
+	 * file servers have no limits, I don't think it matters.
+	 */
+	if (vn_rlimit_fsize(vp, uio, uio->uio_td))
+		return (EFBIG);
+
+	resid = uio->uio_resid;
+	osize = ip->i_size;
+	if (seqcount > BA_SEQMAX)
+		flags = BA_SEQMAX << BA_SEQSHIFT;
+	else
+		flags = seqcount << BA_SEQSHIFT;
+	if ((ioflag & IO_SYNC) && !DOINGASYNC(vp))
+		flags |= IO_SYNC;
+
+	for (error = 0; uio->uio_resid > 0;) {
+		lbn = lblkno(fs, uio->uio_offset);
+		blkoffset = blkoff(fs, uio->uio_offset);
+		xfersize = fs->e2fs_fsize - blkoffset;
+		if (uio->uio_resid < xfersize)
+			xfersize = uio->uio_resid;
+		if (uio->uio_offset + xfersize > ip->i_size)
+			vnode_pager_setsize(vp, uio->uio_offset + xfersize);
+
+                /*
+		 * We must perform a read-before-write if the transfer size
+		 * does not cover the entire buffer.
+                 */
+		if (fs->e2fs_bsize > xfersize)
+			flags |= BA_CLRBUF;
+		else
+			flags &= ~BA_CLRBUF;
+		error = ext2_balloc(ip, lbn, blkoffset + xfersize,
+		    ap->a_cred, &bp, flags);
+		if (error != 0)
+			break;
+
+		/*
+		 * If the buffer is not valid and we did not clear garbage
+		 * out above, we have to do so here even though the write
+		 * covers the entire buffer in order to avoid a mmap()/write
+		 * race where another process may see the garbage prior to
+		 * the uiomove() for a write replacing it.
+		 */
+		if ((bp->b_flags & B_CACHE) == 0 && fs->e2fs_bsize <= xfersize)
+			vfs_bio_clrbuf(bp);
+		if ((ioflag & (IO_SYNC|IO_INVAL)) == (IO_SYNC|IO_INVAL))
+			bp->b_flags |= B_NOCACHE;
+		if (uio->uio_offset + xfersize > ip->i_size)
+			ip->i_size = uio->uio_offset + xfersize;
+		size = blksize(fs, ip, lbn) - bp->b_resid;
+		if (size < xfersize)
+			xfersize = size;
+
+		error =
+		    uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
+		if (ioflag & (IO_VMIO|IO_DIRECT)) {
+			bp->b_flags |= B_RELBUF;
+		}
+
+		/*
+		 * If IO_SYNC each buffer is written synchronously.  Otherwise
+		 * if we have a severe page deficiency write the buffer
+		 * asynchronously.  Otherwise try to cluster, and if that
+		 * doesn't do it then either do an async write (if O_DIRECT),
+		 * or a delayed write (if not).
+		 */
+		if (ioflag & IO_SYNC) {
+			(void)bwrite(bp);
+		} else if (vm_page_count_severe() ||
+		    buf_dirty_count_severe() ||
+		    (ioflag & IO_ASYNC)) {
+			bp->b_flags |= B_CLUSTEROK;
+			bawrite(bp);
+		} else if (xfersize + blkoffset == fs->e2fs_fsize) {
+			if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
+				bp->b_flags |= B_CLUSTEROK;
+				cluster_write(vp, bp, ip->i_size, seqcount);
+			} else {
+				bawrite(bp);
+			}
+		} else if (ioflag & IO_DIRECT) {
+			bp->b_flags |= B_CLUSTEROK;
+			bawrite(bp);
+		} else {
+			bp->b_flags |= B_CLUSTEROK;
+			bdwrite(bp);
+		}
+		if (error || xfersize == 0)
+			break;
+	}
+	/*
+	 * If we successfully wrote any data, and we are not the superuser
+	 * we clear the setuid and setgid bits as a precaution against
+	 * tampering.
+	 */
+	if ((ip->i_mode & (ISUID | ISGID)) && resid > uio->uio_resid &&
+	    ap->a_cred) {
+		if (priv_check_cred(ap->a_cred, PRIV_VFS_RETAINSUGID, 0))
+			ip->i_mode &= ~(ISUID | ISGID);
+	}
+	if (error) {
+		if (ioflag & IO_UNIT) {
+			(void)ext2_truncate(vp, osize,
+			    ioflag & IO_SYNC, ap->a_cred, uio->uio_td);
+			uio->uio_offset -= resid - uio->uio_resid;
+			uio->uio_resid = resid;
+		}
+	}
+	if (uio->uio_resid != resid) {
+               ip->i_flag |= IN_CHANGE | IN_UPDATE;
+               if (ioflag & IO_SYNC)
+                       error = ext2_update(vp, 1);
+       }
+	return (error);
+}



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