kern/159232: fs/ext2fs: merge ext2_readwrite into ext2_vnops
Pedro Giffuni
giffunip at tutopia.com
Wed Jul 27 14:50:09 UTC 2011
>Number: 159232
>Category: kern
>Synopsis: fs/ext2fs: merge ext2_readwrite into ext2_vnops
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: change-request
>Submitter-Id: current-users
>Arrival-Date: Wed Jul 27 14:50:08 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator: Pedro Giffuni
>Release: 9.0-CURRENT
>Organization:
>Environment:
FreeBSD mogwai.giffuni.net 9.0-CURRENT FreeBSD 9.0-CURRENT #6: Sat Apr 30 01:37:57 PDT 2011 root at build9x64.pcbsd.org:/usr/obj/pcbsd-build90/fbsd-source/9.0/sys/PCBSD amd64
>Description:
Follow the comment about removing obfuscations and instead of including ext2_readwrite, move the clustering related functions to ext2_vnops.c
This is consistent to what was done in UFS (SVN 101720) and as similar to
the code in Solaris.
It was suggested by bde at .
>How-To-Repeat:
>Fix:
After applying the patch, ext2_readwrite.c should/must be removed.
Patch attached with submission follows:
--- ext2fs.orig/ext2_vnops.c 2011-04-29 10:15:45.000000000 +0000
+++ ext2fs/ext2_vnops.c 2011-04-30 13:01:47.000000000 +0000
@@ -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 @@
.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 @@
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);
+}
>Release-Note:
>Audit-Trail:
>Unformatted:
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