[net-next-2.6.git] / fs / ufs / truncate.c

/*
 *  linux/fs/ufs/truncate.c
 *
 * Copyright (C) 1998
 * Daniel Pirkl <daniel.pirkl@email.cz>
 * Charles University, Faculty of Mathematics and Physics
 *
 *  from
 *
 *  linux/fs/ext2/truncate.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/fs/minix/truncate.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  Big-endian to little-endian byte-swapping/bitmaps by
 *        David S. Miller (davem@caip.rutgers.edu), 1995
 */

/*
 * Real random numbers for secure rm added 94/02/18
 * Idea from Pierre del Perugia <delperug@gla.ecoledoc.ibp.fr>
 */

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/ufs_fs.h>
#include <linux/fcntl.h>
#include <linux/time.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include <linux/blkdev.h>
#include <linux/sched.h>

#include "swab.h"
#include "util.h"

#undef UFS_TRUNCATE_DEBUG

#ifdef UFS_TRUNCATE_DEBUG
#define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x;
#else
#define UFSD(x)
#endif
 
/*
 * Secure deletion currently doesn't work. It interacts very badly
 * with buffers shared with memory mappings, and for that reason
 * can't be done in the truncate() routines. It should instead be
 * done separately in "release()" before calling the truncate routines
 * that will release the actual file blocks.
 *
 *		Linus
 */

#define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
#define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)

#define DATA_BUFFER_USED(bh) \
	(atomic_read(&bh->b_count)>1 || buffer_locked(bh))

static int ufs_trunc_direct (struct inode * inode)
{
	struct ufs_inode_info *ufsi = UFS_I(inode);
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	struct buffer_head * bh;
	__fs32 * p;
	unsigned frag1, frag2, frag3, frag4, block1, block2;
	unsigned frag_to_free, free_count;
	unsigned i, j, tmp;
	int retry;
	
	UFSD(("ENTER\n"))

	sb = inode->i_sb;
	uspi = UFS_SB(sb)->s_uspi;
	
	frag_to_free = 0;
	free_count = 0;
	retry = 0;
	
	frag1 = DIRECT_FRAGMENT;
	frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
	frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1);
	frag3 = frag4 & ~uspi->s_fpbmask;
	block1 = block2 = 0;
	if (frag2 > frag3) {
		frag2 = frag4;
		frag3 = frag4 = 0;
	}
	else if (frag2 < frag3) {
		block1 = ufs_fragstoblks (frag2);
		block2 = ufs_fragstoblks (frag3);
	}

	UFSD(("frag1 %u, frag2 %u, block1 %u, block2 %u, frag3 %u, frag4 %u\n", frag1, frag2, block1, block2, frag3, frag4))

	if (frag1 >= frag2)
		goto next1;		

	/*
	 * Free first free fragments
	 */
	p = ufsi->i_u1.i_data + ufs_fragstoblks (frag1);
	tmp = fs32_to_cpu(sb, *p);
	if (!tmp )
		ufs_panic (sb, "ufs_trunc_direct", "internal error");
	frag1 = ufs_fragnum (frag1);
	frag2 = ufs_fragnum (frag2);
	for (j = frag1; j < frag2; j++) {
		bh = sb_find_get_block (sb, tmp + j);
		if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) {
			retry = 1;
			brelse (bh);
			goto next1;
		}
		bforget (bh);
	}
	inode->i_blocks -= (frag2-frag1) << uspi->s_nspfshift;
	mark_inode_dirty(inode);
	ufs_free_fragments (inode, tmp + frag1, frag2 - frag1);
	frag_to_free = tmp + frag1;

next1:
	/*
	 * Free whole blocks
	 */
	for (i = block1 ; i < block2; i++) {
		p = ufsi->i_u1.i_data + i;
		tmp = fs32_to_cpu(sb, *p);
		if (!tmp)
			continue;
		for (j = 0; j < uspi->s_fpb; j++) {
			bh = sb_find_get_block(sb, tmp + j);
			if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) {
				retry = 1;
				brelse (bh);
				goto next2;
			}
			bforget (bh);
		}
		*p = 0;
		inode->i_blocks -= uspi->s_nspb;
		mark_inode_dirty(inode);
		if (free_count == 0) {
			frag_to_free = tmp;
			free_count = uspi->s_fpb;
		} else if (free_count > 0 && frag_to_free == tmp - free_count)
			free_count += uspi->s_fpb;
		else {
			ufs_free_blocks (inode, frag_to_free, free_count);
			frag_to_free = tmp;
			free_count = uspi->s_fpb;
		}
next2:;
	}
	
	if (free_count > 0)
		ufs_free_blocks (inode, frag_to_free, free_count);

	if (frag3 >= frag4)
		goto next3;

	/*
	 * Free last free fragments
	 */
	p = ufsi->i_u1.i_data + ufs_fragstoblks (frag3);
	tmp = fs32_to_cpu(sb, *p);
	if (!tmp )
		ufs_panic(sb, "ufs_truncate_direct", "internal error");
	frag4 = ufs_fragnum (frag4);
	for (j = 0; j < frag4; j++) {
		bh = sb_find_get_block (sb, tmp + j);
		if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) {
			retry = 1;
			brelse (bh);
			goto next1;
		}
		bforget (bh);
	}
	*p = 0;
	inode->i_blocks -= frag4 << uspi->s_nspfshift;
	mark_inode_dirty(inode);
	ufs_free_fragments (inode, tmp, frag4);
 next3:

	UFSD(("EXIT\n"))
	return retry;
}


static int ufs_trunc_indirect (struct inode * inode, unsigned offset, __fs32 *p)
{
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	struct ufs_buffer_head * ind_ubh;
	struct buffer_head * bh;
	__fs32 * ind;
	unsigned indirect_block, i, j, tmp;
	unsigned frag_to_free, free_count;
	int retry;

	UFSD(("ENTER\n"))
		
	sb = inode->i_sb;
	uspi = UFS_SB(sb)->s_uspi;

	frag_to_free = 0;
	free_count = 0;
	retry = 0;
	
	tmp = fs32_to_cpu(sb, *p);
	if (!tmp)
		return 0;
	ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
	if (tmp != fs32_to_cpu(sb, *p)) {
		ubh_brelse (ind_ubh);
		return 1;
	}
	if (!ind_ubh) {
		*p = 0;
		return 0;
	}

	indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
	for (i = indirect_block; i < uspi->s_apb; i++) {
		ind = ubh_get_addr32 (ind_ubh, i);
		tmp = fs32_to_cpu(sb, *ind);
		if (!tmp)
			continue;
		for (j = 0; j < uspi->s_fpb; j++) {
			bh = sb_find_get_block(sb, tmp + j);
			if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *ind)) {
				retry = 1;
				brelse (bh);
				goto next;
			}
			bforget (bh);
		}	
		*ind = 0;
		ubh_mark_buffer_dirty(ind_ubh);
		if (free_count == 0) {
			frag_to_free = tmp;
			free_count = uspi->s_fpb;
		} else if (free_count > 0 && frag_to_free == tmp - free_count)
			free_count += uspi->s_fpb;
		else {
			ufs_free_blocks (inode, frag_to_free, free_count);
			frag_to_free = tmp;
			free_count = uspi->s_fpb;
		}
		inode->i_blocks -= uspi->s_nspb;
		mark_inode_dirty(inode);
next:;
	}

	if (free_count > 0) {
		ufs_free_blocks (inode, frag_to_free, free_count);
	}
	for (i = 0; i < uspi->s_apb; i++)
		if (*ubh_get_addr32(ind_ubh,i))
			break;
	if (i >= uspi->s_apb) {
		if (ubh_max_bcount(ind_ubh) != 1) {
			retry = 1;
		}
		else {
			tmp = fs32_to_cpu(sb, *p);
			*p = 0;
			inode->i_blocks -= uspi->s_nspb;
			mark_inode_dirty(inode);
			ufs_free_blocks (inode, tmp, uspi->s_fpb);
			ubh_bforget(ind_ubh);
			ind_ubh = NULL;
		}
	}
	if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
		ubh_ll_rw_block (SWRITE, 1, &ind_ubh);
		ubh_wait_on_buffer (ind_ubh);
	}
	ubh_brelse (ind_ubh);
	
	UFSD(("EXIT\n"))
	
	return retry;
}

static int ufs_trunc_dindirect (struct inode *inode, unsigned offset, __fs32 *p)
{
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	struct ufs_buffer_head * dind_bh;
	unsigned i, tmp, dindirect_block;
	__fs32 * dind;
	int retry = 0;
	
	UFSD(("ENTER\n"))
	
	sb = inode->i_sb;
	uspi = UFS_SB(sb)->s_uspi;

	dindirect_block = (DIRECT_BLOCK > offset) 
		? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
	retry = 0;
	
	tmp = fs32_to_cpu(sb, *p);
	if (!tmp)
		return 0;
	dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
	if (tmp != fs32_to_cpu(sb, *p)) {
		ubh_brelse (dind_bh);
		return 1;
	}
	if (!dind_bh) {
		*p = 0;
		return 0;
	}

	for (i = dindirect_block ; i < uspi->s_apb ; i++) {
		dind = ubh_get_addr32 (dind_bh, i);
		tmp = fs32_to_cpu(sb, *dind);
		if (!tmp)
			continue;
		retry |= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
		ubh_mark_buffer_dirty(dind_bh);
	}

	for (i = 0; i < uspi->s_apb; i++)
		if (*ubh_get_addr32 (dind_bh, i))
			break;
	if (i >= uspi->s_apb) {
		if (ubh_max_bcount(dind_bh) != 1)
			retry = 1;
		else {
			tmp = fs32_to_cpu(sb, *p);
			*p = 0;
			inode->i_blocks -= uspi->s_nspb;
			mark_inode_dirty(inode);
			ufs_free_blocks (inode, tmp, uspi->s_fpb);
			ubh_bforget(dind_bh);
			dind_bh = NULL;
		}
	}
	if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
		ubh_ll_rw_block (SWRITE, 1, &dind_bh);
		ubh_wait_on_buffer (dind_bh);
	}
	ubh_brelse (dind_bh);
	
	UFSD(("EXIT\n"))
	
	return retry;
}

static int ufs_trunc_tindirect (struct inode * inode)
{
	struct ufs_inode_info *ufsi = UFS_I(inode);
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	struct ufs_buffer_head * tind_bh;
	unsigned tindirect_block, tmp, i;
	__fs32 * tind, * p;
	int retry;
	
	UFSD(("ENTER\n"))

	sb = inode->i_sb;
	uspi = UFS_SB(sb)->s_uspi;
	retry = 0;
	
	tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
		? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0;
	p = ufsi->i_u1.i_data + UFS_TIND_BLOCK;
	if (!(tmp = fs32_to_cpu(sb, *p)))
		return 0;
	tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
	if (tmp != fs32_to_cpu(sb, *p)) {
		ubh_brelse (tind_bh);
		return 1;
	}
	if (!tind_bh) {
		*p = 0;
		return 0;
	}

	for (i = tindirect_block ; i < uspi->s_apb ; i++) {
		tind = ubh_get_addr32 (tind_bh, i);
		retry |= ufs_trunc_dindirect(inode, UFS_NDADDR + 
			uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
		ubh_mark_buffer_dirty(tind_bh);
	}
	for (i = 0; i < uspi->s_apb; i++)
		if (*ubh_get_addr32 (tind_bh, i))
			break;
	if (i >= uspi->s_apb) {
		if (ubh_max_bcount(tind_bh) != 1)
			retry = 1;
		else {
			tmp = fs32_to_cpu(sb, *p);
			*p = 0;
			inode->i_blocks -= uspi->s_nspb;
			mark_inode_dirty(inode);
			ufs_free_blocks (inode, tmp, uspi->s_fpb);
			ubh_bforget(tind_bh);
			tind_bh = NULL;
		}
	}
	if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
		ubh_ll_rw_block (SWRITE, 1, &tind_bh);
		ubh_wait_on_buffer (tind_bh);
	}
	ubh_brelse (tind_bh);
	
	UFSD(("EXIT\n"))
	return retry;
}
		
void ufs_truncate (struct inode * inode)
{
	struct ufs_inode_info *ufsi = UFS_I(inode);
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	struct buffer_head * bh;
	unsigned offset;
	int err, retry;
	
	UFSD(("ENTER\n"))
	sb = inode->i_sb;
	uspi = UFS_SB(sb)->s_uspi;

	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
		return;
	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
		return;
	lock_kernel();
	while (1) {
		retry = ufs_trunc_direct(inode);
		retry |= ufs_trunc_indirect (inode, UFS_IND_BLOCK,
			(__fs32 *) &ufsi->i_u1.i_data[UFS_IND_BLOCK]);
		retry |= ufs_trunc_dindirect (inode, UFS_IND_BLOCK + uspi->s_apb,
			(__fs32 *) &ufsi->i_u1.i_data[UFS_DIND_BLOCK]);
		retry |= ufs_trunc_tindirect (inode);
		if (!retry)
			break;
		if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
			ufs_sync_inode (inode);
		blk_run_address_space(inode->i_mapping);
		yield();
	}
	offset = inode->i_size & uspi->s_fshift;
	if (offset) {
		bh = ufs_bread (inode, inode->i_size >> uspi->s_fshift, 0, &err);
		if (bh) {
			memset (bh->b_data + offset, 0, uspi->s_fsize - offset);
			mark_buffer_dirty (bh);
			brelse (bh);
		}
	}
	inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
	ufsi->i_lastfrag = DIRECT_FRAGMENT;
	unlock_kernel();
	mark_inode_dirty(inode);
	UFSD(("EXIT\n"))
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/ufs/truncate.c
	3	*
	4	* Copyright (C) 1998
	5	* Daniel Pirkl <daniel.pirkl@email.cz>
	6	* Charles University, Faculty of Mathematics and Physics
	7	*
	8	* from
	9	*
	10	* linux/fs/ext2/truncate.c
	11	*
	12	* Copyright (C) 1992, 1993, 1994, 1995
	13	* Remy Card (card@masi.ibp.fr)
	14	* Laboratoire MASI - Institut Blaise Pascal
	15	* Universite Pierre et Marie Curie (Paris VI)
	16	*
	17	* from
	18	*
	19	* linux/fs/minix/truncate.c
	20	*
	21	* Copyright (C) 1991, 1992 Linus Torvalds
	22	*
	23	* Big-endian to little-endian byte-swapping/bitmaps by
	24	* David S. Miller (davem@caip.rutgers.edu), 1995
	25	*/
	26
	27	/*
	28	* Real random numbers for secure rm added 94/02/18
	29	* Idea from Pierre del Perugia <delperug@gla.ecoledoc.ibp.fr>
	30	*/
	31
	32	#include <linux/errno.h>
	33	#include <linux/fs.h>
	34	#include <linux/ufs_fs.h>
	35	#include <linux/fcntl.h>
	36	#include <linux/time.h>
	37	#include <linux/stat.h>
	38	#include <linux/string.h>
	39	#include <linux/smp_lock.h>
	40	#include <linux/buffer_head.h>
	41	#include <linux/blkdev.h>
	42	#include <linux/sched.h>
	43
	44	#include "swab.h"
	45	#include "util.h"
	46
	47	#undef UFS_TRUNCATE_DEBUG
	48
	49	#ifdef UFS_TRUNCATE_DEBUG
	50	#define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x;
	51	#else
	52	#define UFSD(x)
	53	#endif
	54
	55	/*
	56	* Secure deletion currently doesn't work. It interacts very badly
	57	* with buffers shared with memory mappings, and for that reason
	58	* can't be done in the truncate() routines. It should instead be
	59	* done separately in "release()" before calling the truncate routines
	60	* that will release the actual file blocks.
	61	*
	62	* Linus
	63	*/
	64
65	#define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
66	#define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)
67
68	#define DATA_BUFFER_USED(bh) \
69	(atomic_read(&bh->b_count)>1 \|\| buffer_locked(bh))
70
71	static int ufs_trunc_direct (struct inode * inode)
72	{
73	struct ufs_inode_info *ufsi = UFS_I(inode);
74	struct super_block * sb;
75	struct ufs_sb_private_info * uspi;
76	struct buffer_head * bh;
77	__fs32 * p;
78	unsigned frag1, frag2, frag3, frag4, block1, block2;
79	unsigned frag_to_free, free_count;
80	unsigned i, j, tmp;
81	int retry;
82
83	UFSD(("ENTER\n"))
84
85	sb = inode->i_sb;
86	uspi = UFS_SB(sb)->s_uspi;
87
88	frag_to_free = 0;
89	free_count = 0;
90	retry = 0;
91
92	frag1 = DIRECT_FRAGMENT;
93	frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
94	frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 \| uspi->s_fpbmask) + 1) : frag1);
95	frag3 = frag4 & ~uspi->s_fpbmask;
96	block1 = block2 = 0;
97	if (frag2 > frag3) {
98	frag2 = frag4;
99	frag3 = frag4 = 0;
100	}
101	else if (frag2 < frag3) {
102	block1 = ufs_fragstoblks (frag2);
103	block2 = ufs_fragstoblks (frag3);
104	}
105
106	UFSD(("frag1 %u, frag2 %u, block1 %u, block2 %u, frag3 %u, frag4 %u\n", frag1, frag2, block1, block2, frag3, frag4))
107
108	if (frag1 >= frag2)
109	goto next1;
110
111	/*
112	* Free first free fragments
113	*/
114	p = ufsi->i_u1.i_data + ufs_fragstoblks (frag1);
115	tmp = fs32_to_cpu(sb, *p);
116	if (!tmp )
117	ufs_panic (sb, "ufs_trunc_direct", "internal error");
118	frag1 = ufs_fragnum (frag1);
119	frag2 = ufs_fragnum (frag2);
120	for (j = frag1; j < frag2; j++) {
121	bh = sb_find_get_block (sb, tmp + j);
122	if ((bh && DATA_BUFFER_USED(bh)) \|\| tmp != fs32_to_cpu(sb, *p)) {
123	retry = 1;
124	brelse (bh);
125	goto next1;
126	}
127	bforget (bh);
128	}
129	inode->i_blocks -= (frag2-frag1) << uspi->s_nspfshift;
130	mark_inode_dirty(inode);
131	ufs_free_fragments (inode, tmp + frag1, frag2 - frag1);
132	frag_to_free = tmp + frag1;
133
134	next1:
135	/*
136	* Free whole blocks
137	*/
138	for (i = block1 ; i < block2; i++) {
139	p = ufsi->i_u1.i_data + i;
140	tmp = fs32_to_cpu(sb, *p);
141	if (!tmp)
142	continue;
143	for (j = 0; j < uspi->s_fpb; j++) {
144	bh = sb_find_get_block(sb, tmp + j);
145	if ((bh && DATA_BUFFER_USED(bh)) \|\| tmp != fs32_to_cpu(sb, *p)) {
146	retry = 1;
147	brelse (bh);
148	goto next2;
149	}
150	bforget (bh);
151	}
152	*p = 0;
153	inode->i_blocks -= uspi->s_nspb;
154	mark_inode_dirty(inode);
155	if (free_count == 0) {
156	frag_to_free = tmp;
157	free_count = uspi->s_fpb;
158	} else if (free_count > 0 && frag_to_free == tmp - free_count)
159	free_count += uspi->s_fpb;
160	else {
161	ufs_free_blocks (inode, frag_to_free, free_count);
162	frag_to_free = tmp;
163	free_count = uspi->s_fpb;
164	}
165	next2:;
166	}
167
168	if (free_count > 0)
169	ufs_free_blocks (inode, frag_to_free, free_count);
170
171	if (frag3 >= frag4)
172	goto next3;
173
174	/*
175	* Free last free fragments
176	*/
177	p = ufsi->i_u1.i_data + ufs_fragstoblks (frag3);
178	tmp = fs32_to_cpu(sb, *p);
179	if (!tmp )
180	ufs_panic(sb, "ufs_truncate_direct", "internal error");
181	frag4 = ufs_fragnum (frag4);
182	for (j = 0; j < frag4; j++) {
183	bh = sb_find_get_block (sb, tmp + j);
184	if ((bh && DATA_BUFFER_USED(bh)) \|\| tmp != fs32_to_cpu(sb, *p)) {
185	retry = 1;
186	brelse (bh);
187	goto next1;
188	}
189	bforget (bh);
190	}
191	*p = 0;
192	inode->i_blocks -= frag4 << uspi->s_nspfshift;
193	mark_inode_dirty(inode);
194	ufs_free_fragments (inode, tmp, frag4);
195	next3:
196
197	UFSD(("EXIT\n"))
198	return retry;
199	}
200
201
202	static int ufs_trunc_indirect (struct inode * inode, unsigned offset, __fs32 *p)
203	{
204	struct super_block * sb;
205	struct ufs_sb_private_info * uspi;
206	struct ufs_buffer_head * ind_ubh;
207	struct buffer_head * bh;
208	__fs32 * ind;
209	unsigned indirect_block, i, j, tmp;
210	unsigned frag_to_free, free_count;
211	int retry;
212
213	UFSD(("ENTER\n"))
214
215	sb = inode->i_sb;
216	uspi = UFS_SB(sb)->s_uspi;
217
218	frag_to_free = 0;
219	free_count = 0;
220	retry = 0;
221
222	tmp = fs32_to_cpu(sb, *p);
223	if (!tmp)
224	return 0;
225	ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
226	if (tmp != fs32_to_cpu(sb, *p)) {
227	ubh_brelse (ind_ubh);
228	return 1;
229	}
230	if (!ind_ubh) {
231	*p = 0;
232	return 0;
233	}
234
235	indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
236	for (i = indirect_block; i < uspi->s_apb; i++) {
237	ind = ubh_get_addr32 (ind_ubh, i);
238	tmp = fs32_to_cpu(sb, *ind);
239	if (!tmp)
240	continue;
241	for (j = 0; j < uspi->s_fpb; j++) {
242	bh = sb_find_get_block(sb, tmp + j);
243	if ((bh && DATA_BUFFER_USED(bh)) \|\| tmp != fs32_to_cpu(sb, *ind)) {
244	retry = 1;
245	brelse (bh);
246	goto next;
247	}
248	bforget (bh);
249	}
250	*ind = 0;
251	ubh_mark_buffer_dirty(ind_ubh);
252	if (free_count == 0) {
253	frag_to_free = tmp;
254	free_count = uspi->s_fpb;
255	} else if (free_count > 0 && frag_to_free == tmp - free_count)
256	free_count += uspi->s_fpb;
257	else {
258	ufs_free_blocks (inode, frag_to_free, free_count);
259	frag_to_free = tmp;
260	free_count = uspi->s_fpb;
261	}
262	inode->i_blocks -= uspi->s_nspb;
263	mark_inode_dirty(inode);
264	next:;
265	}
266
267	if (free_count > 0) {
268	ufs_free_blocks (inode, frag_to_free, free_count);
269	}
270	for (i = 0; i < uspi->s_apb; i++)
271	if (*ubh_get_addr32(ind_ubh,i))
272	break;
273	if (i >= uspi->s_apb) {
274	if (ubh_max_bcount(ind_ubh) != 1) {
275	retry = 1;
276	}
277	else {
278	tmp = fs32_to_cpu(sb, *p);
279	*p = 0;
280	inode->i_blocks -= uspi->s_nspb;
281	mark_inode_dirty(inode);
282	ufs_free_blocks (inode, tmp, uspi->s_fpb);
283	ubh_bforget(ind_ubh);
284	ind_ubh = NULL;
285	}
286	}
287	if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
096125f3	288	ubh_ll_rw_block (SWRITE, 1, &ind_ubh);
1da177e4 LT	289	ubh_wait_on_buffer (ind_ubh);
	290	}
	291	ubh_brelse (ind_ubh);
	292
	293	UFSD(("EXIT\n"))
	294
	295	return retry;
	296	}
	297
	298	static int ufs_trunc_dindirect (struct inode inode, unsigned offset, __fs32 p)
	299	{
	300	struct super_block * sb;
	301	struct ufs_sb_private_info * uspi;
	302	struct ufs_buffer_head * dind_bh;
	303	unsigned i, tmp, dindirect_block;
	304	__fs32 * dind;
	305	int retry = 0;
	306
	307	UFSD(("ENTER\n"))
	308
	309	sb = inode->i_sb;
	310	uspi = UFS_SB(sb)->s_uspi;
	311
	312	dindirect_block = (DIRECT_BLOCK > offset)
	313	? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
	314	retry = 0;
	315
	316	tmp = fs32_to_cpu(sb, *p);
	317	if (!tmp)
	318	return 0;
	319	dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
	320	if (tmp != fs32_to_cpu(sb, *p)) {
	321	ubh_brelse (dind_bh);
	322	return 1;
	323	}
	324	if (!dind_bh) {
	325	*p = 0;
	326	return 0;
	327	}
	328
	329	for (i = dindirect_block ; i < uspi->s_apb ; i++) {
	330	dind = ubh_get_addr32 (dind_bh, i);
	331	tmp = fs32_to_cpu(sb, *dind);
	332	if (!tmp)
	333	continue;
	334	retry \|= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
	335	ubh_mark_buffer_dirty(dind_bh);
	336	}
	337
	338	for (i = 0; i < uspi->s_apb; i++)
	339	if (*ubh_get_addr32 (dind_bh, i))
	340	break;
	341	if (i >= uspi->s_apb) {
	342	if (ubh_max_bcount(dind_bh) != 1)
	343	retry = 1;
	344	else {
	345	tmp = fs32_to_cpu(sb, *p);
	346	*p = 0;
	347	inode->i_blocks -= uspi->s_nspb;
	348	mark_inode_dirty(inode);
	349	ufs_free_blocks (inode, tmp, uspi->s_fpb);
	350	ubh_bforget(dind_bh);
	351	dind_bh = NULL;
	352	}
353	}
354	if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
096125f3	355	ubh_ll_rw_block (SWRITE, 1, &dind_bh);
1da177e4 LT	356	ubh_wait_on_buffer (dind_bh);
	357	}
	358	ubh_brelse (dind_bh);
	359
	360	UFSD(("EXIT\n"))
	361
	362	return retry;
	363	}
	364
	365	static int ufs_trunc_tindirect (struct inode * inode)
	366	{
	367	struct ufs_inode_info *ufsi = UFS_I(inode);
	368	struct super_block * sb;
	369	struct ufs_sb_private_info * uspi;
	370	struct ufs_buffer_head * tind_bh;
	371	unsigned tindirect_block, tmp, i;
	372	__fs32 * tind, * p;
	373	int retry;
	374
	375	UFSD(("ENTER\n"))
	376
	377	sb = inode->i_sb;
	378	uspi = UFS_SB(sb)->s_uspi;
	379	retry = 0;
	380
	381	tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
	382	? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0;
	383	p = ufsi->i_u1.i_data + UFS_TIND_BLOCK;
	384	if (!(tmp = fs32_to_cpu(sb, *p)))
	385	return 0;
	386	tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
	387	if (tmp != fs32_to_cpu(sb, *p)) {
	388	ubh_brelse (tind_bh);
	389	return 1;
	390	}
	391	if (!tind_bh) {
	392	*p = 0;
	393	return 0;
	394	}
	395
	396	for (i = tindirect_block ; i < uspi->s_apb ; i++) {
	397	tind = ubh_get_addr32 (tind_bh, i);
	398	retry \|= ufs_trunc_dindirect(inode, UFS_NDADDR +
	399	uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
	400	ubh_mark_buffer_dirty(tind_bh);
	401	}
	402	for (i = 0; i < uspi->s_apb; i++)
	403	if (*ubh_get_addr32 (tind_bh, i))
	404	break;
	405	if (i >= uspi->s_apb) {
	406	if (ubh_max_bcount(tind_bh) != 1)
	407	retry = 1;
	408	else {
	409	tmp = fs32_to_cpu(sb, *p);
	410	*p = 0;
	411	inode->i_blocks -= uspi->s_nspb;
	412	mark_inode_dirty(inode);
	413	ufs_free_blocks (inode, tmp, uspi->s_fpb);
	414	ubh_bforget(tind_bh);
	415	tind_bh = NULL;
	416	}
	417	}
	418	if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
096125f3	419	ubh_ll_rw_block (SWRITE, 1, &tind_bh);
1da177e4 LT	420	ubh_wait_on_buffer (tind_bh);
	421	}
	422	ubh_brelse (tind_bh);
	423
	424	UFSD(("EXIT\n"))
	425	return retry;
	426	}
	427
	428	void ufs_truncate (struct inode * inode)
	429	{
	430	struct ufs_inode_info *ufsi = UFS_I(inode);
	431	struct super_block * sb;
	432	struct ufs_sb_private_info * uspi;
	433	struct buffer_head * bh;
	434	unsigned offset;
	435	int err, retry;
	436
	437	UFSD(("ENTER\n"))
	438	sb = inode->i_sb;
	439	uspi = UFS_SB(sb)->s_uspi;
	440
	441	if (!(S_ISREG(inode->i_mode) \|\| S_ISDIR(inode->i_mode) \|\| S_ISLNK(inode->i_mode)))
	442	return;
	443	if (IS_APPEND(inode) \|\| IS_IMMUTABLE(inode))
	444	return;
	445	lock_kernel();
	446	while (1) {
	447	retry = ufs_trunc_direct(inode);
	448	retry \|= ufs_trunc_indirect (inode, UFS_IND_BLOCK,
	449	(__fs32 *) &ufsi->i_u1.i_data[UFS_IND_BLOCK]);
	450	retry \|= ufs_trunc_dindirect (inode, UFS_IND_BLOCK + uspi->s_apb,
	451	(__fs32 *) &ufsi->i_u1.i_data[UFS_DIND_BLOCK]);
	452	retry \|= ufs_trunc_tindirect (inode);
	453	if (!retry)
	454	break;
	455	if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
	456	ufs_sync_inode (inode);
	457	blk_run_address_space(inode->i_mapping);
	458	yield();
	459	}
	460	offset = inode->i_size & uspi->s_fshift;
	461	if (offset) {
	462	bh = ufs_bread (inode, inode->i_size >> uspi->s_fshift, 0, &err);
	463	if (bh) {
	464	memset (bh->b_data + offset, 0, uspi->s_fsize - offset);
	465	mark_buffer_dirty (bh);
	466	brelse (bh);
	467	}
	468	}
	469	inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
	470	ufsi->i_lastfrag = DIRECT_FRAGMENT;
	471	unlock_kernel();
	472	mark_inode_dirty(inode);
	473	UFSD(("EXIT\n"))
	474	}