FreeBSD-5.3/sys/gnu/ext2fs/ext2_alloc.c
/*
* modified for Lites 1.1
*
* Aug 1995, Godmar Back (gback@cs.utah.edu)
* University of Utah, Department of Computer Science
*/
/*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ffs_alloc.c 8.8 (Berkeley) 2/21/94
* $FreeBSD: src/sys/gnu/ext2fs/ext2_alloc.c,v 1.38 2004/04/07 20:46:03 imp Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/vnode.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <sys/syslog.h>
#include <gnu/ext2fs/inode.h>
#include <gnu/ext2fs/ext2_mount.h>
#include <gnu/ext2fs/ext2_fs.h>
#include <gnu/ext2fs/ext2_fs_sb.h>
#include <gnu/ext2fs/fs.h>
#include <gnu/ext2fs/ext2_extern.h>
static void ext2_fserr(struct ext2_sb_info *, u_int, char *);
/*
* Linux calls this functions at the following locations:
* (1) the inode is freed
* (2) a preallocation miss occurs
* (3) truncate is called
* (4) release_file is called and f_mode & 2
*
* I call it in ext2_inactive, ext2_truncate, ext2_vfree and in (2)
* the call in vfree might be redundant
*/
void
ext2_discard_prealloc(ip)
struct inode * ip;
{
#ifdef EXT2_PREALLOCATE
if (ip->i_prealloc_count) {
int i = ip->i_prealloc_count;
ip->i_prealloc_count = 0;
ext2_free_blocks (ITOV(ip)->v_mount,
ip->i_prealloc_block,
i);
}
#endif
}
/*
* Allocate a block in the file system.
*
* this takes the framework from ffs_alloc. To implement the
* actual allocation, it calls ext2_new_block, the ported version
* of the same Linux routine.
*
* we note that this is always called in connection with ext2_blkpref
*
* preallocation is done as Linux does it
*/
int
ext2_alloc(ip, lbn, bpref, size, cred, bnp)
struct inode *ip;
int32_t lbn, bpref;
int size;
struct ucred *cred;
int32_t *bnp;
{
struct ext2_sb_info *fs;
int32_t bno;
*bnp = 0;
fs = ip->i_e2fs;
#if DIAGNOSTIC
if ((u_int)size > fs->s_blocksize || blkoff(fs, size) != 0) {
printf("dev = %s, bsize = %lu, size = %d, fs = %s\n",
devtoname(ip->i_dev), fs->s_blocksize, size, fs->fs_fsmnt);
panic("ext2_alloc: bad size");
}
if (cred == NOCRED)
panic("ext2_alloc: missing credential");
#endif /* DIAGNOSTIC */
if (size == fs->s_blocksize && fs->s_es->s_free_blocks_count == 0)
goto nospace;
if (cred->cr_uid != 0 &&
fs->s_es->s_free_blocks_count < fs->s_es->s_r_blocks_count)
goto nospace;
if (bpref >= fs->s_es->s_blocks_count)
bpref = 0;
/* call the Linux code */
#ifdef EXT2_PREALLOCATE
/* To have a preallocation hit, we must
* - have at least one block preallocated
* - and our preferred block must have that block number or one below
*/
if (ip->i_prealloc_count &&
(bpref == ip->i_prealloc_block ||
bpref + 1 == ip->i_prealloc_block))
{
bno = ip->i_prealloc_block++;
ip->i_prealloc_count--;
/* ext2_debug ("preallocation hit (%lu/%lu).\n",
++alloc_hits, ++alloc_attempts); */
/* Linux gets, clears, and releases the buffer at this
point - we don't have to that; we leave it to the caller
*/
} else {
ext2_discard_prealloc (ip);
/* ext2_debug ("preallocation miss (%lu/%lu).\n",
alloc_hits, ++alloc_attempts); */
if (S_ISREG(ip->i_mode))
bno = ext2_new_block
(ITOV(ip)->v_mount, bpref,
&ip->i_prealloc_count,
&ip->i_prealloc_block);
else
bno = (int32_t)ext2_new_block(ITOV(ip)->v_mount,
bpref, 0, 0);
}
#else
bno = (int32_t)ext2_new_block(ITOV(ip)->v_mount, bpref, 0, 0);
#endif
if (bno > 0) {
/* set next_alloc fields as done in block_getblk */
ip->i_next_alloc_block = lbn;
ip->i_next_alloc_goal = bno;
ip->i_blocks += btodb(size);
ip->i_flag |= IN_CHANGE | IN_UPDATE;
*bnp = bno;
return (0);
}
nospace:
ext2_fserr(fs, cred->cr_uid, "file system full");
uprintf("\n%s: write failed, file system is full\n", fs->fs_fsmnt);
return (ENOSPC);
}
/*
* Reallocate a sequence of blocks into a contiguous sequence of blocks.
*
* The vnode and an array of buffer pointers for a range of sequential
* logical blocks to be made contiguous is given. The allocator attempts
* to find a range of sequential blocks starting as close as possible to
* an fs_rotdelay offset from the end of the allocation for the logical
* block immediately preceding the current range. If successful, the
* physical block numbers in the buffer pointers and in the inode are
* changed to reflect the new allocation. If unsuccessful, the allocation
* is left unchanged. The success in doing the reallocation is returned.
* Note that the error return is not reflected back to the user. Rather
* the previous block allocation will be used.
*/
#ifdef FANCY_REALLOC
#include <sys/sysctl.h>
static int doasyncfree = 1;
#ifdef OPT_DEBUG
SYSCTL_INT(_debug, 14, doasyncfree, CTLFLAG_RW, &doasyncfree, 0, "");
#endif /* OPT_DEBUG */
#endif
int
ext2_reallocblks(ap)
struct vop_reallocblks_args /* {
struct vnode *a_vp;
struct cluster_save *a_buflist;
} */ *ap;
{
#ifndef FANCY_REALLOC
/* printf("ext2_reallocblks not implemented\n"); */
return ENOSPC;
#else
struct ext2_sb_info *fs;
struct inode *ip;
struct vnode *vp;
struct buf *sbp, *ebp;
int32_t *bap, *sbap, *ebap;
struct cluster_save *buflist;
int32_t start_lbn, end_lbn, soff, eoff, newblk, blkno;
struct indir start_ap[NIADDR + 1], end_ap[NIADDR + 1], *idp;
int i, len, start_lvl, end_lvl, pref, ssize;
vp = ap->a_vp;
ip = VTOI(vp);
fs = ip->i_e2fs;
#ifdef UNKLAR
if (fs->fs_contigsumsize <= 0)
return (ENOSPC);
#endif
buflist = ap->a_buflist;
len = buflist->bs_nchildren;
start_lbn = buflist->bs_children[0]->b_lblkno;
end_lbn = start_lbn + len - 1;
#if DIAGNOSTIC
for (i = 1; i < len; i++)
if (buflist->bs_children[i]->b_lblkno != start_lbn + i)
panic("ext2_reallocblks: non-cluster");
#endif
/*
* If the latest allocation is in a new cylinder group, assume that
* the filesystem has decided to move and do not force it back to
* the previous cylinder group.
*/
if (dtog(fs, dbtofsb(fs, buflist->bs_children[0]->b_blkno)) !=
dtog(fs, dbtofsb(fs, buflist->bs_children[len - 1]->b_blkno)))
return (ENOSPC);
if (ufs_getlbns(vp, start_lbn, start_ap, &start_lvl) ||
ufs_getlbns(vp, end_lbn, end_ap, &end_lvl))
return (ENOSPC);
/*
* Get the starting offset and block map for the first block.
*/
if (start_lvl == 0) {
sbap = &ip->i_db[0];
soff = start_lbn;
} else {
idp = &start_ap[start_lvl - 1];
if (bread(vp, idp->in_lbn, (int)fs->s_blocksize, NOCRED, &sbp)) {
brelse(sbp);
return (ENOSPC);
}
sbap = (int32_t *)sbp->b_data;
soff = idp->in_off;
}
/*
* Find the preferred location for the cluster.
*/
pref = ext2_blkpref(ip, start_lbn, soff, sbap);
/*
* If the block range spans two block maps, get the second map.
*/
if (end_lvl == 0 || (idp = &end_ap[end_lvl - 1])->in_off + 1 >= len) {
ssize = len;
} else {
#if DIAGNOSTIC
if (start_ap[start_lvl-1].in_lbn == idp->in_lbn)
panic("ext2_reallocblk: start == end");
#endif
ssize = len - (idp->in_off + 1);
if (bread(vp, idp->in_lbn, (int)fs->s_blocksize, NOCRED, &ebp))
goto fail;
ebap = (int32_t *)ebp->b_data;
}
/*
* Search the block map looking for an allocation of the desired size.
*/
if ((newblk = (int32_t)ext2_hashalloc(ip, dtog(fs, pref), (long)pref,
len, (u_long (*)())ext2_clusteralloc)) == 0)
goto fail;
/*
* We have found a new contiguous block.
*
* First we have to replace the old block pointers with the new
* block pointers in the inode and indirect blocks associated
* with the file.
*/
blkno = newblk;
for (bap = &sbap[soff], i = 0; i < len; i++, blkno += fs->s_frags_per_block) {
if (i == ssize)
bap = ebap;
#if DIAGNOSTIC
if (buflist->bs_children[i]->b_blkno != fsbtodb(fs, *bap))
panic("ext2_reallocblks: alloc mismatch");
#endif
*bap++ = blkno;
}
/*
* Next we must write out the modified inode and indirect blocks.
* For strict correctness, the writes should be synchronous since
* the old block values may have been written to disk. In practise
* they are almost never written, but if we are concerned about
* strict correctness, the `doasyncfree' flag should be set to zero.
*
* The test on `doasyncfree' should be changed to test a flag
* that shows whether the associated buffers and inodes have
* been written. The flag should be set when the cluster is
* started and cleared whenever the buffer or inode is flushed.
* We can then check below to see if it is set, and do the
* synchronous write only when it has been cleared.
*/
if (sbap != &ip->i_db[0]) {
if (doasyncfree)
bdwrite(sbp);
else
bwrite(sbp);
} else {
ip->i_flag |= IN_CHANGE | IN_UPDATE;
if (!doasyncfree)
ext2_update(vp, 1);
}
if (ssize < len)
if (doasyncfree)
bdwrite(ebp);
else
bwrite(ebp);
/*
* Last, free the old blocks and assign the new blocks to the buffers.
*/
for (blkno = newblk, i = 0; i < len; i++, blkno += fs->s_frags_per_block) {
ext2_blkfree(ip, dbtofsb(fs, buflist->bs_children[i]->b_blkno),
fs->s_blocksize);
buflist->bs_children[i]->b_blkno = fsbtodb(fs, blkno);
}
return (0);
fail:
if (ssize < len)
brelse(ebp);
if (sbap != &ip->i_db[0])
brelse(sbp);
return (ENOSPC);
#endif /* FANCY_REALLOC */
}
/*
* Allocate an inode in the file system.
*
* we leave the actual allocation strategy to the (modified)
* ext2_new_inode(), to make sure we get the policies right
*/
int
ext2_valloc(pvp, mode, cred, vpp)
struct vnode *pvp;
int mode;
struct ucred *cred;
struct vnode **vpp;
{
struct inode *pip;
struct ext2_sb_info *fs;
struct inode *ip;
ino_t ino;
int i, error;
*vpp = NULL;
pip = VTOI(pvp);
fs = pip->i_e2fs;
if (fs->s_es->s_free_inodes_count == 0)
goto noinodes;
/* call the Linux routine - it returns the inode number only */
ino = ext2_new_inode(pip, mode);
if (ino == 0)
goto noinodes;
error = VFS_VGET(pvp->v_mount, ino, LK_EXCLUSIVE, vpp);
if (error) {
ext2_vfree(pvp, ino, mode);
return (error);
}
ip = VTOI(*vpp);
/*
the question is whether using VGET was such good idea at all -
Linux doesn't read the old inode in when it's allocating a
new one. I will set at least i_size & i_blocks the zero.
*/
ip->i_mode = 0;
ip->i_size = 0;
ip->i_blocks = 0;
ip->i_flags = 0;
/* now we want to make sure that the block pointers are zeroed out */
for (i = 0; i < NDADDR; i++)
ip->i_db[i] = 0;
for (i = 0; i < NIADDR; i++)
ip->i_ib[i] = 0;
/*
* Set up a new generation number for this inode.
* XXX check if this makes sense in ext2
*/
if (ip->i_gen == 0 || ++ip->i_gen == 0)
ip->i_gen = random() / 2 + 1;
/*
printf("ext2_valloc: allocated inode %d\n", ino);
*/
return (0);
noinodes:
ext2_fserr(fs, cred->cr_uid, "out of inodes");
uprintf("\n%s: create/symlink failed, no inodes free\n", fs->fs_fsmnt);
return (ENOSPC);
}
/*
* Select the desired position for the next block in a file.
*
* we try to mimic what Remy does in inode_getblk/block_getblk
*
* we note: blocknr == 0 means that we're about to allocate either
* a direct block or a pointer block at the first level of indirection
* (In other words, stuff that will go in i_db[] or i_ib[])
*
* blocknr != 0 means that we're allocating a block that is none
* of the above. Then, blocknr tells us the number of the block
* that will hold the pointer
*/
int32_t
ext2_blkpref(ip, lbn, indx, bap, blocknr)
struct inode *ip;
int32_t lbn;
int indx;
int32_t *bap;
int32_t blocknr;
{
int tmp;
/* if the next block is actually what we thought it is,
then set the goal to what we thought it should be
*/
if(ip->i_next_alloc_block == lbn)
return ip->i_next_alloc_goal;
/* now check whether we were provided with an array that basically
tells us previous blocks to which we want to stay closeby
*/
if(bap)
for (tmp = indx - 1; tmp >= 0; tmp--)
if (bap[tmp])
return bap[tmp];
/* else let's fall back to the blocknr, or, if there is none,
follow the rule that a block should be allocated near its inode
*/
return blocknr ? blocknr :
(int32_t)(ip->i_block_group *
EXT2_BLOCKS_PER_GROUP(ip->i_e2fs)) +
ip->i_e2fs->s_es->s_first_data_block;
}
/*
* Free a block or fragment.
*
* pass on to the Linux code
*/
void
ext2_blkfree(ip, bno, size)
struct inode *ip;
int32_t bno;
long size;
{
struct ext2_sb_info *fs;
fs = ip->i_e2fs;
/*
* call Linux code with mount *, block number, count
*/
ext2_free_blocks(ITOV(ip)->v_mount, bno, size / fs->s_frag_size);
}
/*
* Free an inode.
*
* the maintenance of the actual bitmaps is again up to the linux code
*/
int
ext2_vfree(pvp, ino, mode)
struct vnode *pvp;
ino_t ino;
int mode;
{
struct ext2_sb_info *fs;
struct inode *pip;
mode_t save_i_mode;
pip = VTOI(pvp);
fs = pip->i_e2fs;
if ((u_int)ino > fs->s_inodes_per_group * fs->s_groups_count)
panic("ext2_vfree: range: dev = (%d, %d), ino = %d, fs = %s",
major(pip->i_dev), minor(pip->i_dev), ino, fs->fs_fsmnt);
/* ext2_debug("ext2_vfree (%d, %d) called\n", pip->i_number, mode);
*/
ext2_discard_prealloc(pip);
/* we need to make sure that ext2_free_inode can adjust the
used_dir_counts in the group summary information - I'd
really like to know what the rationale behind this
'set i_mode to zero to denote an unused inode' is
*/
save_i_mode = pip->i_mode;
pip->i_mode = mode;
ext2_free_inode(pip);
pip->i_mode = save_i_mode;
return (0);
}
/*
* Fserr prints the name of a file system with an error diagnostic.
*
* The form of the error message is:
* fs: error message
*/
static void
ext2_fserr(fs, uid, cp)
struct ext2_sb_info *fs;
u_int uid;
char *cp;
{
log(LOG_ERR, "uid %d on %s: %s\n", uid, fs->fs_fsmnt, cp);
}