cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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anode.c (15773B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 *  linux/fs/hpfs/anode.c
      4 *
      5 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
      6 *
      7 *  handling HPFS anode tree that contains file allocation info
      8 */
      9
     10#include "hpfs_fn.h"
     11
     12/* Find a sector in allocation tree */
     13
     14secno hpfs_bplus_lookup(struct super_block *s, struct inode *inode,
     15		   struct bplus_header *btree, unsigned sec,
     16		   struct buffer_head *bh)
     17{
     18	anode_secno a = -1;
     19	struct anode *anode;
     20	int i;
     21	int c1, c2 = 0;
     22	go_down:
     23	if (hpfs_sb(s)->sb_chk) if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_bplus_lookup")) return -1;
     24	if (bp_internal(btree)) {
     25		for (i = 0; i < btree->n_used_nodes; i++)
     26			if (le32_to_cpu(btree->u.internal[i].file_secno) > sec) {
     27				a = le32_to_cpu(btree->u.internal[i].down);
     28				brelse(bh);
     29				if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
     30				btree = &anode->btree;
     31				goto go_down;
     32			}
     33		hpfs_error(s, "sector %08x not found in internal anode %08x", sec, a);
     34		brelse(bh);
     35		return -1;
     36	}
     37	for (i = 0; i < btree->n_used_nodes; i++)
     38		if (le32_to_cpu(btree->u.external[i].file_secno) <= sec &&
     39		    le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > sec) {
     40			a = le32_to_cpu(btree->u.external[i].disk_secno) + sec - le32_to_cpu(btree->u.external[i].file_secno);
     41			if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, a, 1, "data")) {
     42				brelse(bh);
     43				return -1;
     44			}
     45			if (inode) {
     46				struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
     47				hpfs_inode->i_file_sec = le32_to_cpu(btree->u.external[i].file_secno);
     48				hpfs_inode->i_disk_sec = le32_to_cpu(btree->u.external[i].disk_secno);
     49				hpfs_inode->i_n_secs = le32_to_cpu(btree->u.external[i].length);
     50			}
     51			brelse(bh);
     52			return a;
     53		}
     54	hpfs_error(s, "sector %08x not found in external anode %08x", sec, a);
     55	brelse(bh);
     56	return -1;
     57}
     58
     59/* Add a sector to tree */
     60
     61secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsigned fsecno)
     62{
     63	struct bplus_header *btree;
     64	struct anode *anode = NULL, *ranode = NULL;
     65	struct fnode *fnode;
     66	anode_secno a, na = -1, ra, up = -1;
     67	secno se;
     68	struct buffer_head *bh, *bh1, *bh2;
     69	int n;
     70	unsigned fs;
     71	int c1, c2 = 0;
     72	if (fnod) {
     73		if (!(fnode = hpfs_map_fnode(s, node, &bh))) return -1;
     74		btree = &fnode->btree;
     75	} else {
     76		if (!(anode = hpfs_map_anode(s, node, &bh))) return -1;
     77		btree = &anode->btree;
     78	}
     79	a = node;
     80	go_down:
     81	if ((n = btree->n_used_nodes - 1) < -!!fnod) {
     82		hpfs_error(s, "anode %08x has no entries", a);
     83		brelse(bh);
     84		return -1;
     85	}
     86	if (bp_internal(btree)) {
     87		a = le32_to_cpu(btree->u.internal[n].down);
     88		btree->u.internal[n].file_secno = cpu_to_le32(-1);
     89		mark_buffer_dirty(bh);
     90		brelse(bh);
     91		if (hpfs_sb(s)->sb_chk)
     92			if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_add_sector_to_btree #1")) return -1;
     93		if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
     94		btree = &anode->btree;
     95		goto go_down;
     96	}
     97	if (n >= 0) {
     98		if (le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length) != fsecno) {
     99			hpfs_error(s, "allocated size %08x, trying to add sector %08x, %cnode %08x",
    100				le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length), fsecno,
    101				fnod?'f':'a', node);
    102			brelse(bh);
    103			return -1;
    104		}
    105		if (hpfs_alloc_if_possible(s, se = le32_to_cpu(btree->u.external[n].disk_secno) + le32_to_cpu(btree->u.external[n].length))) {
    106			le32_add_cpu(&btree->u.external[n].length, 1);
    107			mark_buffer_dirty(bh);
    108			brelse(bh);
    109			return se;
    110		}
    111	} else {
    112		if (fsecno) {
    113			hpfs_error(s, "empty file %08x, trying to add sector %08x", node, fsecno);
    114			brelse(bh);
    115			return -1;
    116		}
    117		se = !fnod ? node : (node + 16384) & ~16383;
    118	}	
    119	if (!(se = hpfs_alloc_sector(s, se, 1, fsecno*ALLOC_M>ALLOC_FWD_MAX ? ALLOC_FWD_MAX : fsecno*ALLOC_M<ALLOC_FWD_MIN ? ALLOC_FWD_MIN : fsecno*ALLOC_M))) {
    120		brelse(bh);
    121		return -1;
    122	}
    123	fs = n < 0 ? 0 : le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length);
    124	if (!btree->n_free_nodes) {
    125		up = a != node ? le32_to_cpu(anode->up) : -1;
    126		if (!(anode = hpfs_alloc_anode(s, a, &na, &bh1))) {
    127			brelse(bh);
    128			hpfs_free_sectors(s, se, 1);
    129			return -1;
    130		}
    131		if (a == node && fnod) {
    132			anode->up = cpu_to_le32(node);
    133			anode->btree.flags |= BP_fnode_parent;
    134			anode->btree.n_used_nodes = btree->n_used_nodes;
    135			anode->btree.first_free = btree->first_free;
    136			anode->btree.n_free_nodes = 40 - anode->btree.n_used_nodes;
    137			memcpy(&anode->u, &btree->u, btree->n_used_nodes * 12);
    138			btree->flags |= BP_internal;
    139			btree->n_free_nodes = 11;
    140			btree->n_used_nodes = 1;
    141			btree->first_free = cpu_to_le16((char *)&(btree->u.internal[1]) - (char *)btree);
    142			btree->u.internal[0].file_secno = cpu_to_le32(-1);
    143			btree->u.internal[0].down = cpu_to_le32(na);
    144			mark_buffer_dirty(bh);
    145		} else if (!(ranode = hpfs_alloc_anode(s, /*a*/0, &ra, &bh2))) {
    146			brelse(bh);
    147			brelse(bh1);
    148			hpfs_free_sectors(s, se, 1);
    149			hpfs_free_sectors(s, na, 1);
    150			return -1;
    151		}
    152		brelse(bh);
    153		bh = bh1;
    154		btree = &anode->btree;
    155	}
    156	btree->n_free_nodes--; n = btree->n_used_nodes++;
    157	le16_add_cpu(&btree->first_free, 12);
    158	btree->u.external[n].disk_secno = cpu_to_le32(se);
    159	btree->u.external[n].file_secno = cpu_to_le32(fs);
    160	btree->u.external[n].length = cpu_to_le32(1);
    161	mark_buffer_dirty(bh);
    162	brelse(bh);
    163	if ((a == node && fnod) || na == -1) return se;
    164	c2 = 0;
    165	while (up != (anode_secno)-1) {
    166		struct anode *new_anode;
    167		if (hpfs_sb(s)->sb_chk)
    168			if (hpfs_stop_cycles(s, up, &c1, &c2, "hpfs_add_sector_to_btree #2")) return -1;
    169		if (up != node || !fnod) {
    170			if (!(anode = hpfs_map_anode(s, up, &bh))) return -1;
    171			btree = &anode->btree;
    172		} else {
    173			if (!(fnode = hpfs_map_fnode(s, up, &bh))) return -1;
    174			btree = &fnode->btree;
    175		}
    176		if (btree->n_free_nodes) {
    177			btree->n_free_nodes--; n = btree->n_used_nodes++;
    178			le16_add_cpu(&btree->first_free, 8);
    179			btree->u.internal[n].file_secno = cpu_to_le32(-1);
    180			btree->u.internal[n].down = cpu_to_le32(na);
    181			btree->u.internal[n-1].file_secno = cpu_to_le32(fs);
    182			mark_buffer_dirty(bh);
    183			brelse(bh);
    184			brelse(bh2);
    185			hpfs_free_sectors(s, ra, 1);
    186			if ((anode = hpfs_map_anode(s, na, &bh))) {
    187				anode->up = cpu_to_le32(up);
    188				if (up == node && fnod)
    189					anode->btree.flags |= BP_fnode_parent;
    190				else
    191					anode->btree.flags &= ~BP_fnode_parent;
    192				mark_buffer_dirty(bh);
    193				brelse(bh);
    194			}
    195			return se;
    196		}
    197		up = up != node ? le32_to_cpu(anode->up) : -1;
    198		btree->u.internal[btree->n_used_nodes - 1].file_secno = cpu_to_le32(/*fs*/-1);
    199		mark_buffer_dirty(bh);
    200		brelse(bh);
    201		a = na;
    202		if ((new_anode = hpfs_alloc_anode(s, a, &na, &bh))) {
    203			anode = new_anode;
    204			/*anode->up = cpu_to_le32(up != -1 ? up : ra);*/
    205			anode->btree.flags |= BP_internal;
    206			anode->btree.n_used_nodes = 1;
    207			anode->btree.n_free_nodes = 59;
    208			anode->btree.first_free = cpu_to_le16(16);
    209			anode->btree.u.internal[0].down = cpu_to_le32(a);
    210			anode->btree.u.internal[0].file_secno = cpu_to_le32(-1);
    211			mark_buffer_dirty(bh);
    212			brelse(bh);
    213			if ((anode = hpfs_map_anode(s, a, &bh))) {
    214				anode->up = cpu_to_le32(na);
    215				mark_buffer_dirty(bh);
    216				brelse(bh);
    217			}
    218		} else na = a;
    219	}
    220	if ((anode = hpfs_map_anode(s, na, &bh))) {
    221		anode->up = cpu_to_le32(node);
    222		if (fnod)
    223			anode->btree.flags |= BP_fnode_parent;
    224		mark_buffer_dirty(bh);
    225		brelse(bh);
    226	}
    227	if (!fnod) {
    228		if (!(anode = hpfs_map_anode(s, node, &bh))) {
    229			brelse(bh2);
    230			return -1;
    231		}
    232		btree = &anode->btree;
    233	} else {
    234		if (!(fnode = hpfs_map_fnode(s, node, &bh))) {
    235			brelse(bh2);
    236			return -1;
    237		}
    238		btree = &fnode->btree;
    239	}
    240	ranode->up = cpu_to_le32(node);
    241	memcpy(&ranode->btree, btree, le16_to_cpu(btree->first_free));
    242	if (fnod)
    243		ranode->btree.flags |= BP_fnode_parent;
    244	ranode->btree.n_free_nodes = (bp_internal(&ranode->btree) ? 60 : 40) - ranode->btree.n_used_nodes;
    245	if (bp_internal(&ranode->btree)) for (n = 0; n < ranode->btree.n_used_nodes; n++) {
    246		struct anode *unode;
    247		if ((unode = hpfs_map_anode(s, le32_to_cpu(ranode->u.internal[n].down), &bh1))) {
    248			unode->up = cpu_to_le32(ra);
    249			unode->btree.flags &= ~BP_fnode_parent;
    250			mark_buffer_dirty(bh1);
    251			brelse(bh1);
    252		}
    253	}
    254	btree->flags |= BP_internal;
    255	btree->n_free_nodes = fnod ? 10 : 58;
    256	btree->n_used_nodes = 2;
    257	btree->first_free = cpu_to_le16((char *)&btree->u.internal[2] - (char *)btree);
    258	btree->u.internal[0].file_secno = cpu_to_le32(fs);
    259	btree->u.internal[0].down = cpu_to_le32(ra);
    260	btree->u.internal[1].file_secno = cpu_to_le32(-1);
    261	btree->u.internal[1].down = cpu_to_le32(na);
    262	mark_buffer_dirty(bh);
    263	brelse(bh);
    264	mark_buffer_dirty(bh2);
    265	brelse(bh2);
    266	return se;
    267}
    268
    269/*
    270 * Remove allocation tree. Recursion would look much nicer but
    271 * I want to avoid it because it can cause stack overflow.
    272 */
    273
    274void hpfs_remove_btree(struct super_block *s, struct bplus_header *btree)
    275{
    276	struct bplus_header *btree1 = btree;
    277	struct anode *anode = NULL;
    278	anode_secno ano = 0, oano;
    279	struct buffer_head *bh;
    280	int level = 0;
    281	int pos = 0;
    282	int i;
    283	int c1, c2 = 0;
    284	int d1, d2;
    285	go_down:
    286	d2 = 0;
    287	while (bp_internal(btree1)) {
    288		ano = le32_to_cpu(btree1->u.internal[pos].down);
    289		if (level) brelse(bh);
    290		if (hpfs_sb(s)->sb_chk)
    291			if (hpfs_stop_cycles(s, ano, &d1, &d2, "hpfs_remove_btree #1"))
    292				return;
    293		if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
    294		btree1 = &anode->btree;
    295		level++;
    296		pos = 0;
    297	}
    298	for (i = 0; i < btree1->n_used_nodes; i++)
    299		hpfs_free_sectors(s, le32_to_cpu(btree1->u.external[i].disk_secno), le32_to_cpu(btree1->u.external[i].length));
    300	go_up:
    301	if (!level) return;
    302	brelse(bh);
    303	if (hpfs_sb(s)->sb_chk)
    304		if (hpfs_stop_cycles(s, ano, &c1, &c2, "hpfs_remove_btree #2")) return;
    305	hpfs_free_sectors(s, ano, 1);
    306	oano = ano;
    307	ano = le32_to_cpu(anode->up);
    308	if (--level) {
    309		if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
    310		btree1 = &anode->btree;
    311	} else btree1 = btree;
    312	for (i = 0; i < btree1->n_used_nodes; i++) {
    313		if (le32_to_cpu(btree1->u.internal[i].down) == oano) {
    314			if ((pos = i + 1) < btree1->n_used_nodes)
    315				goto go_down;
    316			else
    317				goto go_up;
    318		}
    319	}
    320	hpfs_error(s,
    321		   "reference to anode %08x not found in anode %08x "
    322		   "(probably bad up pointer)",
    323		   oano, level ? ano : -1);
    324	if (level)
    325		brelse(bh);
    326}
    327
    328/* Just a wrapper around hpfs_bplus_lookup .. used for reading eas */
    329
    330static secno anode_lookup(struct super_block *s, anode_secno a, unsigned sec)
    331{
    332	struct anode *anode;
    333	struct buffer_head *bh;
    334	if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
    335	return hpfs_bplus_lookup(s, NULL, &anode->btree, sec, bh);
    336}
    337
    338int hpfs_ea_read(struct super_block *s, secno a, int ano, unsigned pos,
    339	    unsigned len, char *buf)
    340{
    341	struct buffer_head *bh;
    342	char *data;
    343	secno sec;
    344	unsigned l;
    345	while (len) {
    346		if (ano) {
    347			if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
    348				return -1;
    349		} else sec = a + (pos >> 9);
    350		if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #1")) return -1;
    351		if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
    352			return -1;
    353		l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
    354		memcpy(buf, data + (pos & 0x1ff), l);
    355		brelse(bh);
    356		buf += l; pos += l; len -= l;
    357	}
    358	return 0;
    359}
    360
    361int hpfs_ea_write(struct super_block *s, secno a, int ano, unsigned pos,
    362	     unsigned len, const char *buf)
    363{
    364	struct buffer_head *bh;
    365	char *data;
    366	secno sec;
    367	unsigned l;
    368	while (len) {
    369		if (ano) {
    370			if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
    371				return -1;
    372		} else sec = a + (pos >> 9);
    373		if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #2")) return -1;
    374		if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
    375			return -1;
    376		l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
    377		memcpy(data + (pos & 0x1ff), buf, l);
    378		mark_buffer_dirty(bh);
    379		brelse(bh);
    380		buf += l; pos += l; len -= l;
    381	}
    382	return 0;
    383}
    384
    385void hpfs_ea_remove(struct super_block *s, secno a, int ano, unsigned len)
    386{
    387	struct anode *anode;
    388	struct buffer_head *bh;
    389	if (ano) {
    390		if (!(anode = hpfs_map_anode(s, a, &bh))) return;
    391		hpfs_remove_btree(s, &anode->btree);
    392		brelse(bh);
    393		hpfs_free_sectors(s, a, 1);
    394	} else hpfs_free_sectors(s, a, (len + 511) >> 9);
    395}
    396
    397/* Truncate allocation tree. Doesn't join anodes - I hope it doesn't matter */
    398
    399void hpfs_truncate_btree(struct super_block *s, secno f, int fno, unsigned secs)
    400{
    401	struct fnode *fnode;
    402	struct anode *anode;
    403	struct buffer_head *bh;
    404	struct bplus_header *btree;
    405	anode_secno node = f;
    406	int i, j, nodes;
    407	int c1, c2 = 0;
    408	if (fno) {
    409		if (!(fnode = hpfs_map_fnode(s, f, &bh))) return;
    410		btree = &fnode->btree;
    411	} else {
    412		if (!(anode = hpfs_map_anode(s, f, &bh))) return;
    413		btree = &anode->btree;
    414	}
    415	if (!secs) {
    416		hpfs_remove_btree(s, btree);
    417		if (fno) {
    418			btree->n_free_nodes = 8;
    419			btree->n_used_nodes = 0;
    420			btree->first_free = cpu_to_le16(8);
    421			btree->flags &= ~BP_internal;
    422			mark_buffer_dirty(bh);
    423		} else hpfs_free_sectors(s, f, 1);
    424		brelse(bh);
    425		return;
    426	}
    427	while (bp_internal(btree)) {
    428		nodes = btree->n_used_nodes + btree->n_free_nodes;
    429		for (i = 0; i < btree->n_used_nodes; i++)
    430			if (le32_to_cpu(btree->u.internal[i].file_secno) >= secs) goto f;
    431		brelse(bh);
    432		hpfs_error(s, "internal btree %08x doesn't end with -1", node);
    433		return;
    434		f:
    435		for (j = i + 1; j < btree->n_used_nodes; j++)
    436			hpfs_ea_remove(s, le32_to_cpu(btree->u.internal[j].down), 1, 0);
    437		btree->n_used_nodes = i + 1;
    438		btree->n_free_nodes = nodes - btree->n_used_nodes;
    439		btree->first_free = cpu_to_le16(8 + 8 * btree->n_used_nodes);
    440		mark_buffer_dirty(bh);
    441		if (btree->u.internal[i].file_secno == cpu_to_le32(secs)) {
    442			brelse(bh);
    443			return;
    444		}
    445		node = le32_to_cpu(btree->u.internal[i].down);
    446		brelse(bh);
    447		if (hpfs_sb(s)->sb_chk)
    448			if (hpfs_stop_cycles(s, node, &c1, &c2, "hpfs_truncate_btree"))
    449				return;
    450		if (!(anode = hpfs_map_anode(s, node, &bh))) return;
    451		btree = &anode->btree;
    452	}	
    453	nodes = btree->n_used_nodes + btree->n_free_nodes;
    454	for (i = 0; i < btree->n_used_nodes; i++)
    455		if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) >= secs) goto ff;
    456	brelse(bh);
    457	return;
    458	ff:
    459	if (secs <= le32_to_cpu(btree->u.external[i].file_secno)) {
    460		hpfs_error(s, "there is an allocation error in file %08x, sector %08x", f, secs);
    461		if (i) i--;
    462	}
    463	else if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > secs) {
    464		hpfs_free_sectors(s, le32_to_cpu(btree->u.external[i].disk_secno) + secs -
    465			le32_to_cpu(btree->u.external[i].file_secno), le32_to_cpu(btree->u.external[i].length)
    466			- secs + le32_to_cpu(btree->u.external[i].file_secno)); /* I hope gcc optimizes this :-) */
    467		btree->u.external[i].length = cpu_to_le32(secs - le32_to_cpu(btree->u.external[i].file_secno));
    468	}
    469	for (j = i + 1; j < btree->n_used_nodes; j++)
    470		hpfs_free_sectors(s, le32_to_cpu(btree->u.external[j].disk_secno), le32_to_cpu(btree->u.external[j].length));
    471	btree->n_used_nodes = i + 1;
    472	btree->n_free_nodes = nodes - btree->n_used_nodes;
    473	btree->first_free = cpu_to_le16(8 + 12 * btree->n_used_nodes);
    474	mark_buffer_dirty(bh);
    475	brelse(bh);
    476}
    477
    478/* Remove file or directory and it's eas - note that directory must
    479   be empty when this is called. */
    480
    481void hpfs_remove_fnode(struct super_block *s, fnode_secno fno)
    482{
    483	struct buffer_head *bh;
    484	struct fnode *fnode;
    485	struct extended_attribute *ea;
    486	struct extended_attribute *ea_end;
    487	if (!(fnode = hpfs_map_fnode(s, fno, &bh))) return;
    488	if (!fnode_is_dir(fnode)) hpfs_remove_btree(s, &fnode->btree);
    489	else hpfs_remove_dtree(s, le32_to_cpu(fnode->u.external[0].disk_secno));
    490	ea_end = fnode_end_ea(fnode);
    491	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
    492		if (ea_indirect(ea))
    493			hpfs_ea_remove(s, ea_sec(ea), ea_in_anode(ea), ea_len(ea));
    494	hpfs_ea_ext_remove(s, le32_to_cpu(fnode->ea_secno), fnode_in_anode(fnode), le32_to_cpu(fnode->ea_size_l));
    495	brelse(bh);
    496	hpfs_free_sectors(s, fno, 1);
    497}