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Revision 1.3, Wed Jul 4 19:24:09 2007 UTC (13 years, 9 months ago) by rumble
Branch: MAIN
CVS Tags: yamt-x86pmap-base4, yamt-x86pmap-base3, yamt-x86pmap-base2, yamt-x86pmap-base, yamt-x86pmap, yamt-pf42-baseX, yamt-pf42-base4, yamt-pf42-base3, yamt-pf42-base2, yamt-pf42-base, yamt-pf42, yamt-pagecache-tag8, yamt-pagecache-base9, yamt-pagecache-base8, yamt-pagecache-base7, yamt-pagecache-base6, yamt-pagecache-base5, yamt-pagecache-base4, yamt-pagecache-base3, yamt-pagecache-base2, yamt-pagecache-base, yamt-pagecache, yamt-nfs-mp-base9, yamt-nfs-mp-base8, yamt-nfs-mp-base7, yamt-nfs-mp-base6, yamt-nfs-mp-base5, yamt-nfs-mp-base4, yamt-nfs-mp-base3, yamt-nfs-mp-base2, yamt-nfs-mp-base11, yamt-nfs-mp-base10, yamt-nfs-mp-base, yamt-nfs-mp, yamt-lazymbuf-base15, yamt-lazymbuf-base14, yamt-kmem-base3, yamt-kmem-base2, yamt-kmem-base, yamt-kmem, wrstuden-revivesa-base-4, wrstuden-revivesa-base-3, wrstuden-revivesa-base-2, wrstuden-revivesa-base-1, wrstuden-revivesa-base, wrstuden-revivesa, vmlocking2-base3, vmlocking2-base2, vmlocking2-base1, vmlocking2, vmlocking-nbase, vmlocking-base, uebayasi-xip-base4, uebayasi-xip-base3, uebayasi-xip-base2, uebayasi-xip-base1, uebayasi-xip-base, uebayasi-xip, tls-maxphys-base-20171202, tls-maxphys-base, tls-maxphys, tls-earlyentropy-base, tls-earlyentropy, thorpej-futex-base, thorpej-futex, thorpej-cfargs-base, thorpej-cfargs, simonb-wapbl-nbase, simonb-wapbl-base, simonb-wapbl, rmind-uvmplock-nbase, rmind-uvmplock-base, rmind-uvmplock, rmind-smpnet-nbase, rmind-smpnet-base, rmind-smpnet, riastradh-xf86-video-intel-2-7-1-pre-2-21-15, riastradh-drm2-base3, riastradh-drm2-base2, riastradh-drm2-base1, riastradh-drm2-base, riastradh-drm2, reinoud-bufcleanup-nbase, reinoud-bufcleanup-base, prg-localcount2-base3, prg-localcount2-base2, prg-localcount2-base1, prg-localcount2-base, prg-localcount2, phil-wifi-base, phil-wifi-20200421, phil-wifi-20200411, phil-wifi-20200406, phil-wifi-20191119, phil-wifi-20190609, phil-wifi, pgoyette-localcount-base, pgoyette-localcount-20170426, pgoyette-localcount-20170320, pgoyette-localcount-20170107, pgoyette-localcount-20161104, pgoyette-localcount-20160806, pgoyette-localcount-20160726, pgoyette-localcount, pgoyette-compat-merge-20190127, pgoyette-compat-base, pgoyette-compat-20190127, pgoyette-compat-20190118, pgoyette-compat-1226, pgoyette-compat-1126, pgoyette-compat-1020, pgoyette-compat-0930, pgoyette-compat-0906, pgoyette-compat-0728, pgoyette-compat-0625, pgoyette-compat-0521, pgoyette-compat-0502, pgoyette-compat-0422, pgoyette-compat-0415, pgoyette-compat-0407, pgoyette-compat-0330, pgoyette-compat-0322, pgoyette-compat-0315, pgoyette-compat, perseant-stdc-iso10646-base, perseant-stdc-iso10646, nick-nhusb-base-20170825, nick-nhusb-base-20170204, nick-nhusb-base-20161204, nick-nhusb-base-20161004, nick-nhusb-base-20160907, nick-nhusb-base-20160529, nick-nhusb-base-20160422, nick-nhusb-base-20160319, nick-nhusb-base-20151226, nick-nhusb-base-20150921, nick-nhusb-base-20150606, nick-nhusb-base-20150406, nick-nhusb-base, nick-nhusb, nick-net80211-sync-base, nick-net80211-sync, nick-hppapmap-base4, nick-hppapmap-base3, nick-hppapmap-base2, nick-hppapmap-base, nick-hppapmap, nick-csl-alignment-base5, nick-csl-alignment-base, nick-csl-alignment, netbsd-9-base, netbsd-9-1-RELEASE, netbsd-9-0-RELEASE, netbsd-9-0-RC2, netbsd-9-0-RC1, netbsd-9, netbsd-8-base, netbsd-8-2-RELEASE, netbsd-8-1-RELEASE, netbsd-8-1-RC1, netbsd-8-0-RELEASE, netbsd-8-0-RC2, netbsd-8-0-RC1, netbsd-8, netbsd-7-nhusb-base-20170116, netbsd-7-nhusb-base, netbsd-7-nhusb, netbsd-7-base, netbsd-7-2-RELEASE, netbsd-7-1-RELEASE, netbsd-7-1-RC2, netbsd-7-1-RC1, netbsd-7-1-2-RELEASE, netbsd-7-1-1-RELEASE, netbsd-7-1, netbsd-7-0-RELEASE, netbsd-7-0-RC3, netbsd-7-0-RC2, netbsd-7-0-RC1, netbsd-7-0-2-RELEASE, netbsd-7-0-1-RELEASE, netbsd-7-0, netbsd-7, netbsd-6-base, netbsd-6-1-RELEASE, netbsd-6-1-RC4, netbsd-6-1-RC3, netbsd-6-1-RC2, netbsd-6-1-RC1, netbsd-6-1-5-RELEASE, netbsd-6-1-4-RELEASE, netbsd-6-1-3-RELEASE, netbsd-6-1-2-RELEASE, netbsd-6-1-1-RELEASE, netbsd-6-1, netbsd-6-0-RELEASE, netbsd-6-0-RC2, netbsd-6-0-RC1, netbsd-6-0-6-RELEASE, netbsd-6-0-5-RELEASE, netbsd-6-0-4-RELEASE, netbsd-6-0-3-RELEASE, netbsd-6-0-2-RELEASE, netbsd-6-0-1-RELEASE, netbsd-6-0, netbsd-6, netbsd-5-base, netbsd-5-2-RELEASE, netbsd-5-2-RC1, netbsd-5-2-3-RELEASE, netbsd-5-2-2-RELEASE, netbsd-5-2-1-RELEASE, netbsd-5-2, netbsd-5-1-RELEASE, netbsd-5-1-RC4, netbsd-5-1-RC3, netbsd-5-1-RC2, netbsd-5-1-RC1, netbsd-5-1-5-RELEASE, netbsd-5-1-4-RELEASE, netbsd-5-1-3-RELEASE, netbsd-5-1-2-RELEASE, netbsd-5-1-1-RELEASE, netbsd-5-1, netbsd-5-0-RELEASE, netbsd-5-0-RC4, netbsd-5-0-RC3, netbsd-5-0-RC2, netbsd-5-0-RC1, netbsd-5-0-2-RELEASE, netbsd-5-0-1-RELEASE, netbsd-5-0, netbsd-5, mjf-ufs-trans-base, mjf-devfs2-base, mjf-devfs2, mjf-devfs-base, mjf-devfs, matt-premerge-20091211, matt-nb8-mediatek-base, matt-nb8-mediatek, matt-nb6-plus-nbase, matt-nb6-plus-base, matt-nb6-plus, matt-nb5-pq3-base, matt-nb5-pq3, matt-nb5-mips64-u2-k2-k4-k7-k8-k9, matt-nb5-mips64-u1-k1-k5, matt-nb5-mips64-premerge-20101231, matt-nb5-mips64-premerge-20091211, matt-nb5-mips64-k15, matt-nb5-mips64, matt-nb4-mips64-k7-u2a-k9b, matt-mips64-premerge-20101231, matt-mips64-base2, matt-mips64-base, matt-mips64, matt-armv6-prevmlocking, matt-armv6-nbase, matt-armv6-base, matt-armv6, localcount-20160914, khorben-n900, keiichi-mipv6-nbase, keiichi-mipv6-base, keiichi-mipv6, jymxensuspend-base, jym-xensuspend-nbase, jym-xensuspend-base, jym-xensuspend, jruoho-x86intr-base, jruoho-x86intr, jmcneill-usbmp-pre-base2, jmcneill-usbmp-base9, jmcneill-usbmp-base8, jmcneill-usbmp-base7, jmcneill-usbmp-base6, jmcneill-usbmp-base5, jmcneill-usbmp-base4, jmcneill-usbmp-base3, jmcneill-usbmp-base2, jmcneill-usbmp-base10, jmcneill-usbmp-base, jmcneill-usbmp, jmcneill-pm-base, jmcneill-pm, jmcneill-base, jmcneill-audiomp3-base, jmcneill-audiomp3, jdolecek-ncq-base, jdolecek-ncq, isaki-audio2-base, isaki-audio2, is-mlppp-base, is-mlppp, hpcarm-cleanup-nbase, hpcarm-cleanup-base, hpcarm-cleanup, haad-nbase2, haad-dm-base2, haad-dm-base1, haad-dm-base, haad-dm, cube-autoconf-base, cube-autoconf, cherry-xenmp-base, cherry-xenmp, bouyer-xenpvh-base2, bouyer-xenpvh-base1, bouyer-xenpvh-base, bouyer-xenpvh, bouyer-xeni386-nbase, bouyer-xeni386-merge1, bouyer-xeni386-base, bouyer-xeni386, bouyer-xenamd64-base2, bouyer-xenamd64-base, bouyer-xenamd64, bouyer-socketcan-base1, bouyer-socketcan-base, bouyer-socketcan, bouyer-quota2-nbase, bouyer-quota2-base, bouyer-quota2, agc-symver-base, agc-symver, ad-socklock-base1, ad-namecache-base3, ad-namecache-base2, ad-namecache-base1, ad-namecache-base, ad-namecache, ad-audiomp2-base, ad-audiomp2, HEAD
Branch point for: yamt-lazymbuf, vmlocking
Changes since 1.2: +3 -1 lines

Additional fixes/enhancements:
    1) Comply with the way buffercache(9) is intended to be used. Now we
       read in single blocks of EFS_BB_SIZE, never taking in variable
       length extents with a single bread() call.

    2) Handle symlinks with more than one extent. There's no reason for
       this to ever happen, but it's handled now.

    3) Finally, add a hint to our iteration initialiser so we can start
       from the desired offset, rather than naively looping through from
       the beginning each time. Since we can binary search the correct
       location quickly, this improves large sequential reads by about
       40% with 128MB files. Improvement should increase with file size.

/*	$NetBSD: efs_extent.h,v 1.3 2007/07/04 19:24:09 rumble Exp $	*/

/*
 * Copyright (c) 2006 Stephen M. Rumble <rumble@ephemeral.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * EFS extent descriptor format and sundry.
 *
 * See IRIX inode(4)
 */

#ifndef _FS_EFS_EFS_EXTENT_H_
#define _FS_EFS_EFS_EXTENT_H_

/*
 * EFS on-disk extent descriptor (8 bytes)
 *
 * SGI smushed this structure's members into bit fields, but we have to
 * be a little more portable. Therefore we use the efs_extent (see below)
 * type for in-core manipulation and convert immediately to and from disk.
 */
struct efs_dextent {
	union {
		uint64_t ex_magic:8,	/* magic number (always 0) */
			 ex_bn:24,	/* bb number in filesystem */
			 ex_length:8,	/* length of extent (in bb) */
			 ex_offset:24;	/* logical file offset (in bb) */
		uint8_t  bytes[8];
		uint32_t words[2];
	} ex_muddle;
} __packed;
#define ex_bytes ex_muddle.bytes
#define ex_words ex_muddle.words

/*
 * In-core, unsquished representation of an extent.
 */
struct efs_extent {
	uint8_t  ex_magic;
	uint32_t ex_bn;			/* NB: only 24 bits on disk */
	uint8_t  ex_length;
	uint32_t ex_offset;		/* NB: only 24 bits on disk */
};

#define EFS_EXTENT_MAGIC	0
#define EFS_EXTENT_BN_MASK	0x00ffffff
#define EFS_EXTENT_OFFSET_MASK	0x00ffffff

#define EFS_EXTENTS_PER_BB	(EFS_BB_SIZE / sizeof(struct efs_dextent))

#endif /* !_FS_EFS_EFS_EXTENT_H_ */