/*
* Balloc defines the structure of file system storage
* by allocating the physical blocks on a device given
* the inode and the logical block number in a file.
*/
ffs_balloc(
register struct inode *ip,
register ufs_daddr_t lbn,
int size,
kauth_cred_t cred,
struct buf **bpp,
int flags,
int * blk_alloc)
{
register struct fs *fs;
register ufs_daddr_t nb;
struct buf *bp, *nbp;
struct vnode *vp = ITOV(ip);
struct indir indirs[NIADDR + 2];
ufs_daddr_t newb, *bap, pref;
int deallocated, osize, nsize, num, i, error;
ufs_daddr_t *allocib, *blkp, *allocblk, allociblk[NIADDR + 1];
int devBlockSize=0;
int alloc_buffer = 1;
struct mount *mp=vp->v_mount;
#if REV_ENDIAN_FS
int rev_endian=(mp->mnt_flag & MNT_REVEND);
#endif /* REV_ENDIAN_FS */
*bpp = NULL;
if (lbn < 0)
return (EFBIG);
fs = ip->i_fs;
if (flags & B_NOBUFF)
alloc_buffer = 0;
if (blk_alloc)
*blk_alloc = 0;
/*
* If the next write will extend the file into a new block,
* and the file is currently composed of a fragment
* this fragment has to be extended to be a full block.
*/
nb = lblkno(fs, ip->i_size);
if (nb < NDADDR && nb < lbn) {
/* the filesize prior to this write can fit in direct
* blocks (ie. fragmentaion is possibly done)
* we are now extending the file write beyond
* the block which has end of file prior to this write
*/
osize = blksize(fs, ip, nb);
/* osize gives disk allocated size in the last block. It is
* either in fragments or a file system block size */
if (osize < fs->fs_bsize && osize > 0) {
/* few fragments are already allocated,since the
* current extends beyond this block
* allocate the complete block as fragments are only
* in last block
*/
error = ffs_realloccg(ip, nb,
ffs_blkpref(ip, nb, (int)nb, &ip->i_db[0]),
osize, (int)fs->fs_bsize, cred, &bp);
if (error)
return (error);
/* adjust the inode size we just grew */
/* it is in nb+1 as nb starts from 0 */
ip->i_size = (nb + 1) * fs->fs_bsize;
ubc_setsize(vp, (off_t)ip->i_size);
ip->i_db[nb] = dbtofsb(fs, (ufs_daddr_t)buf_blkno(bp));
ip->i_flag |= IN_CHANGE | IN_UPDATE;
if ((flags & B_SYNC) || (!alloc_buffer)) {
if (!alloc_buffer)
buf_setflags(bp, B_NOCACHE);
buf_bwrite(bp);
} else
buf_bdwrite(bp);
/* note that bp is already released here */
}
}
/*
* The first NDADDR blocks are direct blocks
*/
if (lbn < NDADDR) {
nb = ip->i_db[lbn];
if (nb != 0 && ip->i_size >= (lbn + 1) * fs->fs_bsize) {
if (alloc_buffer) {
error = (int)buf_bread(vp, (daddr64_t)((unsigned)lbn), fs->fs_bsize, NOCRED, &bp);
if (error) {
buf_brelse(bp);
return (error);
}
*bpp = bp;
}
return (0);
}
if (nb != 0) {
/*
* Consider need to reallocate a fragment.
*/
osize = fragroundup(fs, blkoff(fs, ip->i_size));
nsize = fragroundup(fs, size);
if (nsize <= osize) {
if (alloc_buffer) {
error = (int)buf_bread(vp, (daddr64_t)((unsigned)lbn), osize, NOCRED, &bp);
if (error) {
buf_brelse(bp);
return (error);
}
ip->i_flag |= IN_CHANGE | IN_UPDATE;
*bpp = bp;
return (0);
}
else {
ip->i_flag |= IN_CHANGE | IN_UPDATE;
return (0);
}
} else {
error = ffs_realloccg(ip, lbn,
ffs_blkpref(ip, lbn, (int)lbn,
&ip->i_db[0]), osize, nsize, cred, &bp);
if (error)
return (error);
ip->i_db[lbn] = dbtofsb(fs, (ufs_daddr_t)buf_blkno(bp));
ip->i_flag |= IN_CHANGE | IN_UPDATE;
/* adjust the inode size we just grew */
ip->i_size = (lbn * fs->fs_bsize) + size;
ubc_setsize(vp, (off_t)ip->i_size);
if (!alloc_buffer) {
buf_setflags(bp, B_NOCACHE);
if (flags & B_SYNC)
buf_bwrite(bp);
else
buf_bdwrite(bp);
} else
*bpp = bp;
return (0);
}
} else {
if (ip->i_size < (lbn + 1) * fs->fs_bsize)
nsize = fragroundup(fs, size);
else
nsize = fs->fs_bsize;
error = ffs_alloc(ip, lbn,
ffs_blkpref(ip, lbn, (int)lbn, &ip->i_db[0]),
nsize, cred, &newb);
if (error)
return (error);
if (alloc_buffer) {
bp = buf_getblk(vp, (daddr64_t)((unsigned)lbn), nsize, 0, 0, BLK_WRITE);
buf_setblkno(bp, (daddr64_t)((unsigned)fsbtodb(fs, newb)));
if (flags & B_CLRBUF)
buf_clear(bp);
}
ip->i_db[lbn] = newb;
ip->i_flag |= IN_CHANGE | IN_UPDATE;
if (blk_alloc) {
*blk_alloc = nsize;
}
if (alloc_buffer)
*bpp = bp;
return (0);
}
}
/*
* Determine the number of levels of indirection.
*/
pref = 0;
if (error = ufs_getlbns(vp, lbn, indirs, &num))
return(error);
#if DIAGNOSTIC
if (num < 1)
panic ("ffs_balloc: ufs_bmaparray returned indirect block");
#endif
/*
* Fetch the first indirect block allocating if necessary.
*/
--num;
nb = ip->i_ib[indirs[0].in_off];
allocib = NULL;
allocblk = allociblk;
if (nb == 0) {
pref = ffs_blkpref(ip, lbn, 0, (ufs_daddr_t *)0);
if (error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
cred, &newb))
return (error);
nb = newb;
*allocblk++ = nb;
bp = buf_getblk(vp, (daddr64_t)((unsigned)(indirs[1].in_lbn)), fs->fs_bsize, 0, 0, BLK_META);
buf_setblkno(bp, (daddr64_t)((unsigned)fsbtodb(fs, nb)));
buf_clear(bp);
/*
* Write synchronously conditional on mount flags.
*/
if ((vp)->v_mount->mnt_flag & MNT_ASYNC) {
error = 0;
buf_bdwrite(bp);
} else if ((error = buf_bwrite(bp)) != 0) {
goto fail;
}
allocib = &ip->i_ib[indirs[0].in_off];
*allocib = nb;
ip->i_flag |= IN_CHANGE | IN_UPDATE;
}
/*
* Fetch through the indirect blocks, allocating as necessary.
*/
for (i = 1;;) {
error = (int)buf_meta_bread(vp, (daddr64_t)((unsigned)(indirs[i].in_lbn)), (int)fs->fs_bsize, NOCRED, &bp);
if (error) {
buf_brelse(bp);
goto fail;
}
bap = (ufs_daddr_t *)buf_dataptr(bp);
#if REV_ENDIAN_FS
if (rev_endian)
nb = OSSwapInt32(bap[indirs[i].in_off]);
else {
#endif /* REV_ENDIAN_FS */
nb = bap[indirs[i].in_off];
#if REV_ENDIAN_FS
}
#endif /* REV_ENDIAN_FS */
if (i == num)
break;
i += 1;
if (nb != 0) {
buf_brelse(bp);
continue;
}
if (pref == 0)
pref = ffs_blkpref(ip, lbn, 0, (ufs_daddr_t *)0);
if (error =
ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
buf_brelse(bp);
goto fail;
}
nb = newb;
*allocblk++ = nb;
nbp = buf_getblk(vp, (daddr64_t)((unsigned)(indirs[i].in_lbn)), fs->fs_bsize, 0, 0, BLK_META);
buf_setblkno(nbp, (daddr64_t)((unsigned)fsbtodb(fs, nb)));
buf_clear(nbp);
/*
* Write synchronously conditional on mount flags.
*/
if ((vp)->v_mount->mnt_flag & MNT_ASYNC) {
error = 0;
buf_bdwrite(nbp);
} else if (error = buf_bwrite(nbp)) {
buf_brelse(bp);
goto fail;
}
#if REV_ENDIAN_FS
if (rev_endian)
bap[indirs[i - 1].in_off] = OSSwapInt32(nb);
else {
#endif /* REV_ENDIAN_FS */
bap[indirs[i - 1].in_off] = nb;
#if REV_ENDIAN_FS
}
#endif /* REV_ENDIAN_FS */
/*
* If required, write synchronously, otherwise use
* delayed write.
*/
if (flags & B_SYNC) {
buf_bwrite(bp);
} else {
buf_bdwrite(bp);
}
}
/*
* Get the data block, allocating if necessary.
*/
if (nb == 0) {
pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]);
if (error = ffs_alloc(ip,
lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
buf_brelse(bp);
goto fail;
}
nb = newb;
*allocblk++ = nb;
#if REV_ENDIAN_FS
if (rev_endian)
bap[indirs[i].in_off] = OSSwapInt32(nb);
else {
#endif /* REV_ENDIAN_FS */
bap[indirs[i].in_off] = nb;
#if REV_ENDIAN_FS
}
#endif /* REV_ENDIAN_FS */
/*
* If required, write synchronously, otherwise use
* delayed write.
*/
if ((flags & B_SYNC)) {
buf_bwrite(bp);
} else {
buf_bdwrite(bp);
}
if(alloc_buffer ) {
nbp = buf_getblk(vp, (daddr64_t)((unsigned)lbn), fs->fs_bsize, 0, 0, BLK_WRITE);
buf_setblkno(nbp, (daddr64_t)((unsigned)fsbtodb(fs, nb)));
if (flags & B_CLRBUF)
buf_clear(nbp);
}
if (blk_alloc) {
*blk_alloc = fs->fs_bsize;
}
if(alloc_buffer)
*bpp = nbp;
return (0);
}
buf_brelse(bp);
if (alloc_buffer) {
if (flags & B_CLRBUF) {
error = (int)buf_bread(vp, (daddr64_t)((unsigned)lbn), (int)fs->fs_bsize, NOCRED, &nbp);
if (error) {
buf_brelse(nbp);
goto fail;
}
} else {
nbp = buf_getblk(vp, (daddr64_t)((unsigned)lbn), fs->fs_bsize, 0, 0, BLK_WRITE);
buf_setblkno(nbp, (daddr64_t)((unsigned)fsbtodb(fs, nb)));
}
*bpp = nbp;
}
return (0);
fail:
/*
* If we have failed part way through block allocation, we
* have to deallocate any indirect blocks that we have allocated.
*/
for (deallocated = 0, blkp = allociblk; blkp < allocblk; blkp++) {
ffs_blkfree(ip, *blkp, fs->fs_bsize);
deallocated += fs->fs_bsize;
}
if (allocib != NULL)
*allocib = 0;
if (deallocated) {
devBlockSize = vfs_devblocksize(mp);
#if QUOTA
/*
* Restore user's disk quota because allocation failed.
*/
(void) chkdq(ip, (int64_t)-deallocated, cred, FORCE);
#endif /* QUOTA */
ip->i_blocks -= btodb(deallocated, devBlockSize);
ip->i_flag |= IN_CHANGE | IN_UPDATE;
}
return (error);
}
/*
* ffs_balloc(struct vnode *a_vp, ufs_daddr_t a_lbn, int a_size,
* struct ucred *a_cred, int a_flags, struct buf *a_bpp)
*
* Balloc defines the structure of filesystem storage by allocating
* the physical blocks on a device given the inode and the logical
* block number in a file.
*
* NOTE: B_CLRBUF - this flag tells balloc to clear invalid portions
* of the buffer. However, any dirty bits will override missing
* valid bits. This case occurs when writable mmaps are truncated
* and then extended.
*/
int
ffs_balloc(struct vop_balloc_args *ap)
{
struct inode *ip;
ufs_daddr_t lbn;
int size;
struct ucred *cred;
int flags;
struct fs *fs;
ufs_daddr_t nb;
struct buf *bp, *nbp, *dbp;
struct vnode *vp;
struct indir indirs[NIADDR + 2];
ufs_daddr_t newb, *bap, pref;
int deallocated, osize, nsize, num, i, error;
ufs_daddr_t *allocib, *blkp, *allocblk, allociblk[NIADDR + 1];
ufs_daddr_t *lbns_remfree, lbns[NIADDR + 1];
int unwindidx;
int seqcount;
vp = ap->a_vp;
ip = VTOI(vp);
fs = ip->i_fs;
lbn = lblkno(fs, ap->a_startoffset);
size = blkoff(fs, ap->a_startoffset) + ap->a_size;
if (size > fs->fs_bsize)
panic("ffs_balloc: blk too big");
*ap->a_bpp = NULL;
if (lbn < 0)
return (EFBIG);
cred = ap->a_cred;
flags = ap->a_flags;
/*
* The vnode must be locked for us to be able to safely mess
* around with the inode.
*/
if (vn_islocked(vp) != LK_EXCLUSIVE) {
panic("ffs_balloc: vnode %p not exclusively locked!", vp);
}
/*
* If the next write will extend the file into a new block,
* and the file is currently composed of a fragment
* this fragment has to be extended to be a full block.
*/
nb = lblkno(fs, ip->i_size);
if (nb < NDADDR && nb < lbn) {
/*
* The filesize prior to this write can fit in direct
* blocks (ex. fragmentation is possibly done)
* we are now extending the file write beyond
* the block which has end of the file prior to this write.
*/
osize = blksize(fs, ip, nb);
/*
* osize gives disk allocated size in the last block. It is
* either in fragments or a file system block size.
*/
if (osize < fs->fs_bsize && osize > 0) {
/* A few fragments are already allocated, since the
* current extends beyond this block allocated the
* complete block as fragments are on in last block.
*/
error = ffs_realloccg(ip, nb,
ffs_blkpref(ip, nb, (int)nb, &ip->i_db[0]),
osize, (int)fs->fs_bsize, cred, &bp);
if (error)
return (error);
if (DOINGSOFTDEP(vp))
softdep_setup_allocdirect(ip, nb,
dofftofsb(fs, bp->b_bio2.bio_offset),
ip->i_db[nb], fs->fs_bsize, osize, bp);
/* adjust the inode size, we just grew */
ip->i_size = smalllblktosize(fs, nb + 1);
ip->i_db[nb] = dofftofsb(fs, bp->b_bio2.bio_offset);
ip->i_flag |= IN_CHANGE | IN_UPDATE;
if (flags & B_SYNC)
bwrite(bp);
else
bawrite(bp);
/* bp is already released here */
}
}
/*
* The first NDADDR blocks are direct blocks
*/
if (lbn < NDADDR) {
nb = ip->i_db[lbn];
if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) {
error = bread(vp, lblktodoff(fs, lbn), fs->fs_bsize, &bp);
if (error) {
brelse(bp);
return (error);
}
bp->b_bio2.bio_offset = fsbtodoff(fs, nb);
*ap->a_bpp = bp;
return (0);
}
if (nb != 0) {
/*
* Consider need to reallocate a fragment.
*/
osize = fragroundup(fs, blkoff(fs, ip->i_size));
nsize = fragroundup(fs, size);
if (nsize <= osize) {
error = bread(vp, lblktodoff(fs, lbn),
osize, &bp);
if (error) {
brelse(bp);
return (error);
}
bp->b_bio2.bio_offset = fsbtodoff(fs, nb);
} else {
/*
* NOTE: ffs_realloccg() issues a bread().
*/
error = ffs_realloccg(ip, lbn,
ffs_blkpref(ip, lbn, (int)lbn,
&ip->i_db[0]), osize, nsize, cred, &bp);
if (error)
return (error);
if (DOINGSOFTDEP(vp))
softdep_setup_allocdirect(ip, lbn,
dofftofsb(fs, bp->b_bio2.bio_offset),
nb, nsize, osize, bp);
}
} else {
if (ip->i_size < smalllblktosize(fs, lbn + 1))
nsize = fragroundup(fs, size);
else
nsize = fs->fs_bsize;
error = ffs_alloc(ip, lbn,
ffs_blkpref(ip, lbn, (int)lbn, &ip->i_db[0]),
nsize, cred, &newb);
if (error)
return (error);
bp = getblk(vp, lblktodoff(fs, lbn), nsize, 0, 0);
bp->b_bio2.bio_offset = fsbtodoff(fs, newb);
if (flags & B_CLRBUF)
vfs_bio_clrbuf(bp);
if (DOINGSOFTDEP(vp))
softdep_setup_allocdirect(ip, lbn, newb, 0,
nsize, 0, bp);
}
ip->i_db[lbn] = dofftofsb(fs, bp->b_bio2.bio_offset);
ip->i_flag |= IN_CHANGE | IN_UPDATE;
*ap->a_bpp = bp;
return (0);
}
/*
* Determine the number of levels of indirection.
*/
pref = 0;
if ((error = ufs_getlbns(vp, lbn, indirs, &num)) != 0)
return(error);
#ifdef DIAGNOSTIC
if (num < 1)
panic ("ffs_balloc: ufs_bmaparray returned indirect block");
#endif
/*
* Get a handle on the data block buffer before working through
* indirect blocks to avoid a deadlock between the VM system holding
* a locked VM page and issuing a BMAP (which tries to lock the
* indirect blocks), and the filesystem holding a locked indirect
* block and then trying to read a data block (which tries to lock
* the underlying VM pages).
*/
dbp = getblk(vp, lblktodoff(fs, lbn), fs->fs_bsize, 0, 0);
/*
* Setup undo history
*/
allocib = NULL;
allocblk = allociblk;
lbns_remfree = lbns;
unwindidx = -1;
/*
* Fetch the first indirect block directly from the inode, allocating
* one if necessary.
*/
--num;
nb = ip->i_ib[indirs[0].in_off];
if (nb == 0) {
pref = ffs_blkpref(ip, lbn, 0, NULL);
/*
* If the filesystem has run out of space we can skip the
* full fsync/undo of the main [fail] case since no undo
* history has been built yet. Hence the goto fail2.
*/
if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
cred, &newb)) != 0)
goto fail2;
nb = newb;
*allocblk++ = nb;
*lbns_remfree++ = indirs[1].in_lbn;
bp = getblk(vp, lblktodoff(fs, indirs[1].in_lbn),
fs->fs_bsize, 0, 0);
bp->b_bio2.bio_offset = fsbtodoff(fs, nb);
vfs_bio_clrbuf(bp);
if (DOINGSOFTDEP(vp)) {
softdep_setup_allocdirect(ip, NDADDR + indirs[0].in_off,
newb, 0, fs->fs_bsize, 0, bp);
bdwrite(bp);
} else {
/*
* Write synchronously so that indirect blocks
* never point at garbage.
*/
if (DOINGASYNC(vp))
bdwrite(bp);
else if ((error = bwrite(bp)) != 0)
goto fail;
}
allocib = &ip->i_ib[indirs[0].in_off];
*allocib = nb;
ip->i_flag |= IN_CHANGE | IN_UPDATE;
}
/*
* Fetch through the indirect blocks, allocating as necessary.
*/
for (i = 1;;) {
error = bread(vp, lblktodoff(fs, indirs[i].in_lbn), (int)fs->fs_bsize, &bp);
if (error) {
brelse(bp);
goto fail;
}
bap = (ufs_daddr_t *)bp->b_data;
nb = bap[indirs[i].in_off];
if (i == num)
break;
i += 1;
if (nb != 0) {
bqrelse(bp);
continue;
}
if (pref == 0)
pref = ffs_blkpref(ip, lbn, 0, NULL);
if ((error =
ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) != 0) {
brelse(bp);
goto fail;
}
nb = newb;
*allocblk++ = nb;
*lbns_remfree++ = indirs[i].in_lbn;
nbp = getblk(vp, lblktodoff(fs, indirs[i].in_lbn),
fs->fs_bsize, 0, 0);
nbp->b_bio2.bio_offset = fsbtodoff(fs, nb);
vfs_bio_clrbuf(nbp);
if (DOINGSOFTDEP(vp)) {
softdep_setup_allocindir_meta(nbp, ip, bp,
indirs[i - 1].in_off, nb);
bdwrite(nbp);
} else {
/*
* Write synchronously so that indirect blocks
* never point at garbage.
*/
if ((error = bwrite(nbp)) != 0) {
brelse(bp);
goto fail;
}
}
bap[indirs[i - 1].in_off] = nb;
if (allocib == NULL && unwindidx < 0)
unwindidx = i - 1;
/*
* If required, write synchronously, otherwise use
* delayed write.
*/
if (flags & B_SYNC) {
bwrite(bp);
} else {
if (bp->b_bufsize == fs->fs_bsize)
bp->b_flags |= B_CLUSTEROK;
bdwrite(bp);
}
}
/*
* Get the data block, allocating if necessary. We have already
* called getblk() on the data block buffer, dbp. If we have to
* allocate it and B_CLRBUF has been set the inference is an intention
* to zero out the related disk blocks, so we do not have to issue
* a read. Instead we simply call vfs_bio_clrbuf(). If B_CLRBUF is
* not set the caller intends to overwrite the entire contents of the
* buffer and we don't waste time trying to clean up the contents.
*
* bp references the current indirect block. When allocating,
* the block must be updated.
*/
if (nb == 0) {
pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]);
error = ffs_alloc(ip,
lbn, pref, (int)fs->fs_bsize, cred, &newb);
if (error) {
brelse(bp);
goto fail;
}
nb = newb;
*allocblk++ = nb;
*lbns_remfree++ = lbn;
dbp->b_bio2.bio_offset = fsbtodoff(fs, nb);
if (flags & B_CLRBUF)
vfs_bio_clrbuf(dbp);
if (DOINGSOFTDEP(vp))
softdep_setup_allocindir_page(ip, lbn, bp,
indirs[i].in_off, nb, 0, dbp);
bap[indirs[i].in_off] = nb;
/*
* If required, write synchronously, otherwise use
* delayed write.
*/
if (flags & B_SYNC) {
bwrite(bp);
} else {
if (bp->b_bufsize == fs->fs_bsize)
bp->b_flags |= B_CLUSTEROK;
bdwrite(bp);
}
*ap->a_bpp = dbp;
return (0);
}
brelse(bp);
/*
* At this point all related indirect blocks have been allocated
* if necessary and released. bp is no longer valid. dbp holds
* our getblk()'d data block.
*
* XXX we previously performed a cluster_read operation here.
*/
if (flags & B_CLRBUF) {
/*
* If B_CLRBUF is set we must validate the invalid portions
* of the buffer. This typically requires a read-before-
* write. The strategy call will fill in bio_offset in that
* case.
*
* If we hit this case we do a cluster read if possible
* since nearby data blocks are likely to be accessed soon
* too.
*/
if ((dbp->b_flags & B_CACHE) == 0) {
bqrelse(dbp);
seqcount = (flags & B_SEQMASK) >> B_SEQSHIFT;
if (seqcount &&
(vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
error = cluster_read(vp, (off_t)ip->i_size,
lblktodoff(fs, lbn),
(int)fs->fs_bsize,
fs->fs_bsize,
seqcount * BKVASIZE,
&dbp);
} else {
error = bread(vp, lblktodoff(fs, lbn),
(int)fs->fs_bsize, &dbp);
}
if (error)
goto fail;
} else {
/*
* ffs_blkalloc allocates a disk block for ffs_pageout(), as a consequence
* it does no buf_breads (that could lead to deadblock as the page may be already
* marked busy as it is being paged out. Also important to note that we are not
* growing the file in pageouts. So ip->i_size cannot increase by this call
* due to the way UBC works.
* This code is derived from ffs_balloc and many cases of that are dealt
* in ffs_balloc are not applicable here
* Do not call with B_CLRBUF flags as this should only be called only
* from pageouts
*/
ffs_blkalloc(
struct inode *ip,
ufs_daddr_t lbn,
int size,
kauth_cred_t cred,
int flags)
{
register struct fs *fs;
register ufs_daddr_t nb;
struct buf *bp, *nbp;
struct vnode *vp = ITOV(ip);
struct indir indirs[NIADDR + 2];
ufs_daddr_t newb, *bap, pref;
int deallocated, osize, nsize, num, i, error;
ufs_daddr_t *allocib, *blkp, *allocblk, allociblk[NIADDR + 1];
int devBlockSize=0;
struct mount *mp=vp->v_mount;
#if REV_ENDIAN_FS
int rev_endian=(mp->mnt_flag & MNT_REVEND);
#endif /* REV_ENDIAN_FS */
fs = ip->i_fs;
if(size > fs->fs_bsize)
panic("ffs_blkalloc: too large for allocation");
/*
* If the next write will extend the file into a new block,
* and the file is currently composed of a fragment
* this fragment has to be extended to be a full block.
*/
nb = lblkno(fs, ip->i_size);
if (nb < NDADDR && nb < lbn) {
panic("ffs_blkalloc():cannot extend file: i_size %d, lbn %d", ip->i_size, lbn);
}
/*
* The first NDADDR blocks are direct blocks
*/
if (lbn < NDADDR) {
nb = ip->i_db[lbn];
if (nb != 0 && ip->i_size >= (lbn + 1) * fs->fs_bsize) {
/* TBD: trivial case; the block is already allocated */
return (0);
}
if (nb != 0) {
/*
* Consider need to reallocate a fragment.
*/
osize = fragroundup(fs, blkoff(fs, ip->i_size));
nsize = fragroundup(fs, size);
if (nsize > osize) {
panic("ffs_allocblk: trying to extend a fragment");
}
return(0);
} else {
if (ip->i_size < (lbn + 1) * fs->fs_bsize)
nsize = fragroundup(fs, size);
else
nsize = fs->fs_bsize;
error = ffs_alloc(ip, lbn,
ffs_blkpref(ip, lbn, (int)lbn, &ip->i_db[0]),
nsize, cred, &newb);
if (error)
return (error);
ip->i_db[lbn] = newb;
ip->i_flag |= IN_CHANGE | IN_UPDATE;
return (0);
}
}
/*
* Determine the number of levels of indirection.
*/
pref = 0;
if (error = ufs_getlbns(vp, lbn, indirs, &num))
return(error);
if(num == 0) {
panic("ffs_blkalloc: file with direct blocks only");
}
/*
* Fetch the first indirect block allocating if necessary.
*/
--num;
nb = ip->i_ib[indirs[0].in_off];
allocib = NULL;
allocblk = allociblk;
if (nb == 0) {
pref = ffs_blkpref(ip, lbn, 0, (ufs_daddr_t *)0);
if (error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
cred, &newb))
return (error);
nb = newb;
*allocblk++ = nb;
bp = buf_getblk(vp, (daddr64_t)((unsigned)(indirs[1].in_lbn)), fs->fs_bsize, 0, 0, BLK_META);
buf_setblkno(bp, (daddr64_t)((unsigned)fsbtodb(fs, nb)));
buf_clear(bp);
/*
* Write synchronously conditional on mount flags.
*/
if ((vp)->v_mount->mnt_flag & MNT_ASYNC) {
error = 0;
buf_bdwrite(bp);
} else if (error = buf_bwrite(bp)) {
goto fail;
}
allocib = &ip->i_ib[indirs[0].in_off];
*allocib = nb;
ip->i_flag |= IN_CHANGE | IN_UPDATE;
}
/*
* Fetch through the indirect blocks, allocating as necessary.
*/
for (i = 1;;) {
error = (int)buf_meta_bread(vp, (daddr64_t)((unsigned)(indirs[i].in_lbn)), (int)fs->fs_bsize, NOCRED, &bp);
if (error) {
buf_brelse(bp);
goto fail;
}
bap = (ufs_daddr_t *)buf_dataptr(bp);
#if REV_ENDIAN_FS
if (rev_endian)
nb = OSSwapInt32(bap[indirs[i].in_off]);
else {
#endif /* REV_ENDIAN_FS */
nb = bap[indirs[i].in_off];
#if REV_ENDIAN_FS
}
#endif /* REV_ENDIAN_FS */
if (i == num)
break;
i += 1;
if (nb != 0) {
buf_brelse(bp);
continue;
}
if (pref == 0)
pref = ffs_blkpref(ip, lbn, 0, (ufs_daddr_t *)0);
if (error =
ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
buf_brelse(bp);
goto fail;
}
nb = newb;
*allocblk++ = nb;
nbp = buf_getblk(vp, (daddr64_t)((unsigned)(indirs[i].in_lbn)), fs->fs_bsize, 0, 0, BLK_META);
buf_setblkno(nbp, (daddr64_t)((unsigned)fsbtodb(fs, nb)));
buf_clear(nbp);
/*
* Write synchronously conditional on mount flags.
*/
if ((vp)->v_mount->mnt_flag & MNT_ASYNC) {
error = 0;
buf_bdwrite(nbp);
} else if (error = buf_bwrite(nbp)) {
buf_brelse(bp);
goto fail;
}
#if REV_ENDIAN_FS
if (rev_endian)
bap[indirs[i - 1].in_off] = OSSwapInt32(nb);
else {
#endif /* REV_ENDIAN_FS */
bap[indirs[i - 1].in_off] = nb;
#if REV_ENDIAN_FS
}
#endif /* REV_ENDIAN_FS */
/*
* If required, write synchronously, otherwise use
* delayed write.
*/
if (flags & B_SYNC) {
buf_bwrite(bp);
} else {
buf_bdwrite(bp);
}
}
/*
* Get the data block, allocating if necessary.
*/
if (nb == 0) {
pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]);
if (error = ffs_alloc(ip,
lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
buf_brelse(bp);
goto fail;
}
nb = newb;
*allocblk++ = nb;
#if REV_ENDIAN_FS
if (rev_endian)
bap[indirs[i].in_off] = OSSwapInt32(nb);
else {
#endif /* REV_ENDIAN_FS */
bap[indirs[i].in_off] = nb;
#if REV_ENDIAN_FS
}
#endif /* REV_ENDIAN_FS */
/*
* If required, write synchronously, otherwise use
* delayed write.
*/
if (flags & B_SYNC) {
buf_bwrite(bp);
} else {
buf_bdwrite(bp);
}
return (0);
}
buf_brelse(bp);
return (0);
fail:
/*
* If we have failed part way through block allocation, we
* have to deallocate any indirect blocks that we have allocated.
*/
for (deallocated = 0, blkp = allociblk; blkp < allocblk; blkp++) {
ffs_blkfree(ip, *blkp, fs->fs_bsize);
deallocated += fs->fs_bsize;
}
if (allocib != NULL)
*allocib = 0;
if (deallocated) {
devBlockSize = vfs_devblocksize(mp);
#if QUOTA
/*
* Restore user's disk quota because allocation failed.
*/
(void) chkdq(ip, (int64_t)-deallocated, cred, FORCE);
#endif /* QUOTA */
ip->i_blocks -= btodb(deallocated, devBlockSize);
ip->i_flag |= IN_CHANGE | IN_UPDATE;
}
return (error);
}