Author: kib Date: Mon Nov 30 17:03:26 2020 New Revision: 368191 URL: https://svnweb.freebsd.org/changeset/base/368191
Log: ffs: do not read full direct blocks if they are going to be overwritten. BA_CLRBUF specifies that existing context of the block will be completely overwritten by caller, so there is no reason to spend io fetching existing data. We do the same for indirect blocks. Reported by: tmunro Reviewed by: mckusick, tmunro Tested by: pho, tmunro Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D27353 Modified: head/sys/ufs/ffs/ffs_balloc.c Modified: head/sys/ufs/ffs/ffs_balloc.c ============================================================================== --- head/sys/ufs/ffs/ffs_balloc.c Mon Nov 30 17:00:36 2020 (r368190) +++ head/sys/ufs/ffs/ffs_balloc.c Mon Nov 30 17:03:26 2020 (r368191) @@ -172,9 +172,17 @@ ffs_balloc_ufs1(struct vnode *vp, off_t startoffset, i panic("ffs_balloc_ufs1: BA_METAONLY for direct block"); nb = dp->di_db[lbn]; if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) { - error = bread(vp, lbn, fs->fs_bsize, NOCRED, &bp); - if (error) { - return (error); + if ((flags & BA_CLRBUF) != 0) { + error = bread(vp, lbn, fs->fs_bsize, NOCRED, + &bp); + if (error != 0) + return (error); + } else { + bp = getblk(vp, lbn, fs->fs_bsize, 0, 0, + gbflags); + if (bp == NULL) + return (EIO); + vfs_bio_clrbuf(bp); } bp->b_blkno = fsbtodb(fs, nb); *bpp = bp; @@ -768,10 +776,17 @@ ffs_balloc_ufs2(struct vnode *vp, off_t startoffset, i panic("ffs_balloc_ufs2: BA_METAONLY for direct block"); nb = dp->di_db[lbn]; if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) { - error = bread_gb(vp, lbn, fs->fs_bsize, NOCRED, - gbflags, &bp); - if (error) { - return (error); + if ((flags & BA_CLRBUF) != 0) { + error = bread_gb(vp, lbn, fs->fs_bsize, NOCRED, + gbflags, &bp); + if (error != 0) + return (error); + } else { + bp = getblk(vp, lbn, fs->fs_bsize, 0, 0, + gbflags); + if (bp == NULL) + return (EIO); + vfs_bio_clrbuf(bp); } bp->b_blkno = fsbtodb(fs, nb); *bpp = bp; _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
