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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [fs/] [minix/] [truncate.c] - Blame information for rev 1628

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/*
 *  linux/fs/truncate.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  Copyright (C) 1996  Gertjan van Wingerde (gertjan@cs.vu.nl)
 *      Minix V2 fs support.
 */
 
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/minix_fs.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
 
#define DIRECT_BLOCK            ((inode->i_size + 1023) >> 10)
#define INDIRECT_BLOCK(offset)  (DIRECT_BLOCK-offset)
#define V1_DINDIRECT_BLOCK(offset) ((DIRECT_BLOCK-offset)>>9)
#define V2_DINDIRECT_BLOCK(offset) ((DIRECT_BLOCK-offset)>>8)
#define TINDIRECT_BLOCK(offset) ((DIRECT_BLOCK-(offset))>>8)
 
/*
 * Truncate has the most races in the whole filesystem: coding it is
 * a pain in the a**. Especially as I don't do any locking...
 *
 * The code may look a bit weird, but that's just because I've tried to
 * handle things like file-size changes in a somewhat graceful manner.
 * Anyway, truncating a file at the same time somebody else writes to it
 * is likely to result in pretty weird behaviour...
 *
 * The new code handles normal truncates (size = 0) as well as the more
 * general case (size = XXX). I hope.
 */
 
/*
 * The functions for minix V1 fs truncation.
 */
static int V1_trunc_direct(struct inode * inode)
{
        unsigned short * p;
        struct buffer_head * bh;
        int i, tmp;
        int retry = 0;
 
repeat:
        for (i = DIRECT_BLOCK ; i < 7 ; i++) {
                p = i + inode->u.minix_i.u.i1_data;
                if (!(tmp = *p))
                        continue;
                bh = get_hash_table(inode->i_dev,tmp,BLOCK_SIZE);
                if (i < DIRECT_BLOCK) {
                        brelse(bh);
                        goto repeat;
                }
                if ((bh && bh->b_count != 1) || tmp != *p) {
                        retry = 1;
                        brelse(bh);
                        continue;
                }
                *p = 0;
                inode->i_dirt = 1;
                if (bh) {
                        mark_buffer_clean(bh);
                        brelse(bh);
                }
                minix_free_block(inode->i_sb,tmp);
        }
        return retry;
}
 
static int V1_trunc_indirect(struct inode * inode, int offset, unsigned short * p)
{
        struct buffer_head * bh;
        int i, tmp;
        struct buffer_head * ind_bh;
        unsigned short * ind;
        int retry = 0;
 
        tmp = *p;
        if (!tmp)
                return 0;
        ind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);
        if (tmp != *p) {
                brelse(ind_bh);
                return 1;
        }
        if (!ind_bh) {
                *p = 0;
                return 0;
        }
repeat:
        for (i = INDIRECT_BLOCK(offset) ; i < 512 ; i++) {
                if (i < 0)
                        i = 0;
                if (i < INDIRECT_BLOCK(offset))
                        goto repeat;
                ind = i+(unsigned short *) ind_bh->b_data;
                tmp = *ind;
                if (!tmp)
                        continue;
                bh = get_hash_table(inode->i_dev,tmp,BLOCK_SIZE);
                if (i < INDIRECT_BLOCK(offset)) {
                        brelse(bh);
                        goto repeat;
                }
                if ((bh && bh->b_count != 1) || tmp != *ind) {
                        retry = 1;
                        brelse(bh);
                        continue;
                }
                *ind = 0;
                mark_buffer_dirty(ind_bh, 1);
                brelse(bh);
                minix_free_block(inode->i_sb,tmp);
        }
        ind = (unsigned short *) ind_bh->b_data;
        for (i = 0; i < 512; i++)
                if (*(ind++))
                        break;
        if (i >= 512)
                if (ind_bh->b_count != 1)
                        retry = 1;
                else {
                        tmp = *p;
                        *p = 0;
                        minix_free_block(inode->i_sb,tmp);
                }
        brelse(ind_bh);
        return retry;
}
 
static int V1_trunc_dindirect(struct inode * inode, int offset, unsigned short *p)
{
        int i, tmp;
        struct buffer_head * dind_bh;
        unsigned short * dind;
        int retry = 0;
 
        if (!(tmp = *p))
                return 0;
        dind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);
        if (tmp != *p) {
                brelse(dind_bh);
                return 1;
        }
        if (!dind_bh) {
                *p = 0;
                return 0;
        }
repeat:
        for (i = V1_DINDIRECT_BLOCK(offset) ; i < 512 ; i ++) {
                if (i < 0)
                        i = 0;
                if (i < V1_DINDIRECT_BLOCK(offset))
                        goto repeat;
                dind = i+(unsigned short *) dind_bh->b_data;
                retry |= V1_trunc_indirect(inode,offset+(i<<9),dind);
                mark_buffer_dirty(dind_bh, 1);
        }
        dind = (unsigned short *) dind_bh->b_data;
        for (i = 0; i < 512; i++)
                if (*(dind++))
                        break;
        if (i >= 512)
                if (dind_bh->b_count != 1)
                        retry = 1;
                else {
                        tmp = *p;
                        *p = 0;
                        inode->i_dirt = 1;
                        minix_free_block(inode->i_sb,tmp);
                }
        brelse(dind_bh);
        return retry;
}
 
void V1_minix_truncate(struct inode * inode)
{
        int retry;
 
        if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
             S_ISLNK(inode->i_mode)))
                return;
        while (1) {
                retry = V1_trunc_direct(inode);
                retry |= V1_trunc_indirect(inode, 7, inode->u.minix_i.u.i1_data + 7);
                retry |= V1_trunc_dindirect(inode, 7+512, inode->u.minix_i.u.i1_data + 8);
                if (!retry)
                        break;
                current->counter = 0;
                schedule();
        }
        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
        inode->i_dirt = 1;
}
 
/*
 * The functions for minix V2 fs truncation.
 */
static int V2_trunc_direct(struct inode * inode)
{
        unsigned long * p;
        struct buffer_head * bh;
        int i, tmp;
        int retry = 0;
 
repeat:
        for (i = DIRECT_BLOCK ; i < 7 ; i++) {
                p = (unsigned long *) inode->u.minix_i.u.i2_data + i;
                if (!(tmp = *p))
                        continue;
                bh = get_hash_table(inode->i_dev,tmp,BLOCK_SIZE);
                if (i < DIRECT_BLOCK) {
                        brelse(bh);
                        goto repeat;
                }
                if ((bh && bh->b_count != 1) || tmp != *p) {
                        retry = 1;
                        brelse(bh);
                        continue;
                }
                *p = 0;
                inode->i_dirt = 1;
                if (bh) {
                        mark_buffer_clean(bh);
                        brelse(bh);
                }
                minix_free_block(inode->i_sb,tmp);
        }
        return retry;
}
 
static int V2_trunc_indirect(struct inode * inode, int offset, unsigned long * p)
{
        struct buffer_head * bh;
        int i, tmp;
        struct buffer_head * ind_bh;
        unsigned long * ind;
        int retry = 0;
 
        tmp = *p;
        if (!tmp)
                return 0;
        ind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);
        if (tmp != *p) {
                brelse(ind_bh);
                return 1;
        }
        if (!ind_bh) {
                *p = 0;
                return 0;
        }
repeat:
        for (i = INDIRECT_BLOCK(offset) ; i < 256 ; i++) {
                if (i < 0)
                        i = 0;
                if (i < INDIRECT_BLOCK(offset))
                        goto repeat;
                ind = i+(unsigned long *) ind_bh->b_data;
                tmp = *ind;
                if (!tmp)
                        continue;
                bh = get_hash_table(inode->i_dev,tmp,BLOCK_SIZE);
                if (i < INDIRECT_BLOCK(offset)) {
                        brelse(bh);
                        goto repeat;
                }
                if ((bh && bh->b_count != 1) || tmp != *ind) {
                        retry = 1;
                        brelse(bh);
                        continue;
                }
                *ind = 0;
                mark_buffer_dirty(ind_bh, 1);
                brelse(bh);
                minix_free_block(inode->i_sb,tmp);
        }
        ind = (unsigned long *) ind_bh->b_data;
        for (i = 0; i < 256; i++)
                if (*(ind++))
                        break;
        if (i >= 256)
                if (ind_bh->b_count != 1)
                        retry = 1;
                else {
                        tmp = *p;
                        *p = 0;
                        minix_free_block(inode->i_sb,tmp);
                }
        brelse(ind_bh);
        return retry;
}
 
static int V2_trunc_dindirect(struct inode * inode, int offset, unsigned long *p)
{
        int i, tmp;
        struct buffer_head * dind_bh;
        unsigned long * dind;
        int retry = 0;
 
        if (!(tmp = *p))
                return 0;
        dind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);
        if (tmp != *p) {
                brelse(dind_bh);
                return 1;
        }
        if (!dind_bh) {
                *p = 0;
                return 0;
        }
repeat:
        for (i = V2_DINDIRECT_BLOCK(offset) ; i < 256 ; i ++) {
                if (i < 0)
                        i = 0;
                if (i < V2_DINDIRECT_BLOCK(offset))
                        goto repeat;
                dind = i+(unsigned long *) dind_bh->b_data;
                retry |= V2_trunc_indirect(inode,offset+(i<<8),dind);
                mark_buffer_dirty(dind_bh, 1);
        }
        dind = (unsigned long *) dind_bh->b_data;
        for (i = 0; i < 256; i++)
                if (*(dind++))
                        break;
        if (i >= 256)
                if (dind_bh->b_count != 1)
                        retry = 1;
                else {
                        tmp = *p;
                        *p = 0;
                        inode->i_dirt = 1;
                        minix_free_block(inode->i_sb,tmp);
                }
        brelse(dind_bh);
        return retry;
}
 
static int V2_trunc_tindirect(struct inode * inode, int offset, unsigned long * p)
{
        int i, tmp;
        struct buffer_head * tind_bh;
        unsigned long * tind;
        int retry = 0;
 
        if (!(tmp = *p))
                return 0;
        tind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);
        if (tmp != *p) {
                brelse(tind_bh);
                return 1;
        }
        if (!tind_bh) {
                *p = 0;
                return 0;
        }
repeat:
        for (i = TINDIRECT_BLOCK(offset) ; i < 256 ; i ++) {
                if (i < 0)
                        i = 0;
                if (i < TINDIRECT_BLOCK(offset))
                        goto repeat;
                tind = i+(unsigned long *) tind_bh->b_data;
                retry |= V2_trunc_dindirect(inode,offset+(i<<8),tind);
                mark_buffer_dirty(tind_bh, 1);
        }
        tind = (unsigned long *) tind_bh->b_data;
        for (i = 0; i < 256; i++)
                if (*(tind++))
                        break;
        if (i >= 256)
                if (tind_bh->b_count != 1)
                        retry = 1;
                else {
                        tmp = *p;
                        *p = 0;
                        inode->i_dirt = 1;
                        minix_free_block(inode->i_sb,tmp);
                }
        brelse(tind_bh);
        return retry;
}
 
static void V2_minix_truncate(struct inode * inode)
{
        int retry;
 
        if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
             S_ISLNK(inode->i_mode)))
                return;
        while (1) {
                retry = V2_trunc_direct(inode);
                retry |= V2_trunc_indirect(inode,7,
                        (unsigned long *) inode->u.minix_i.u.i2_data + 7);
                retry |= V2_trunc_dindirect(inode, 7+256,
                        (unsigned long *) inode->u.minix_i.u.i2_data + 8);
                retry |= V2_trunc_tindirect(inode, 7+256+256*256,
                        (unsigned long *) inode->u.minix_i.u.i2_data + 9);
                if (!retry)
                        break;
                current->counter = 0;
                schedule();
        }
        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
        inode->i_dirt = 1;
}
 
/*
 * The function that is called for file truncation.
 */
void minix_truncate(struct inode * inode)
{
        if (INODE_VERSION(inode) == MINIX_V1)
                V1_minix_truncate(inode);
        else
                V2_minix_truncate(inode);
}

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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [fs/] [minix/] [truncate.c] - Blame information for rev 1628

Line No.	Rev	Author	Line
1	1628	jcastillo	`/*`
2			`* linux/fs/truncate.c`
3			`*`
4			`* Copyright (C) 1991, 1992 Linus Torvalds`
5			`*`
6			`* Copyright (C) 1996 Gertjan van Wingerde (gertjan@cs.vu.nl)`
7			`* Minix V2 fs support.`
8			`*/`
9
10			`#include <linux/errno.h>`
11			`#include <linux/sched.h>`
12			`#include <linux/minix_fs.h>`
13			`#include <linux/stat.h>`
14			`#include <linux/fcntl.h>`
15
16			`#define DIRECT_BLOCK ((inode->i_size + 1023) >> 10)`
17			`#define INDIRECT_BLOCK(offset) (DIRECT_BLOCK-offset)`
18			`#define V1_DINDIRECT_BLOCK(offset) ((DIRECT_BLOCK-offset)>>9)`
19			`#define V2_DINDIRECT_BLOCK(offset) ((DIRECT_BLOCK-offset)>>8)`
20			`#define TINDIRECT_BLOCK(offset) ((DIRECT_BLOCK-(offset))>>8)`
21
22			`/*`
23			`* Truncate has the most races in the whole filesystem: coding it is`
24			`* a pain in the a**. Especially as I don't do any locking...`
25			`*`
26			`* The code may look a bit weird, but that's just because I've tried to`
27			`* handle things like file-size changes in a somewhat graceful manner.`
28			`* Anyway, truncating a file at the same time somebody else writes to it`
29			`* is likely to result in pretty weird behaviour...`
30			`*`
31			`* The new code handles normal truncates (size = 0) as well as the more`
32			`* general case (size = XXX). I hope.`
33			`*/`
34
35			`/*`
36			`* The functions for minix V1 fs truncation.`
37			`*/`
38			`static int V1_trunc_direct(struct inode * inode)`
39			`{`
40			`unsigned short * p;`
41			`struct buffer_head * bh;`
42			`int i, tmp;`
43			`int retry = 0;`
44
45			`repeat:`
46			`for (i = DIRECT_BLOCK ; i < 7 ; i++) {`
47			`p = i + inode->u.minix_i.u.i1_data;`
48			`if (!(tmp = *p))`
49			`continue;`
50			`bh = get_hash_table(inode->i_dev,tmp,BLOCK_SIZE);`
51			`if (i < DIRECT_BLOCK) {`
52			`brelse(bh);`
53			`goto repeat;`
54			`}`
55			`if ((bh && bh->b_count != 1) \|\| tmp != *p) {`
56			`retry = 1;`
57			`brelse(bh);`
58			`continue;`
59			`}`
60			`*p = 0;`
61			`inode->i_dirt = 1;`
62			`if (bh) {`
63			`mark_buffer_clean(bh);`
64			`brelse(bh);`
65			`}`
66			`minix_free_block(inode->i_sb,tmp);`
67			`}`
68			`return retry;`
69			`}`
70
71			`static int V1_trunc_indirect(struct inode * inode, int offset, unsigned short * p)`
72			`{`
73			`struct buffer_head * bh;`
74			`int i, tmp;`
75			`struct buffer_head * ind_bh;`
76			`unsigned short * ind;`
77			`int retry = 0;`
78
79			`tmp = *p;`
80			`if (!tmp)`
81			`return 0;`
82			`ind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);`
83			`if (tmp != *p) {`
84			`brelse(ind_bh);`
85			`return 1;`
86			`}`
87			`if (!ind_bh) {`
88			`*p = 0;`
89			`return 0;`
90			`}`
91			`repeat:`
92			`for (i = INDIRECT_BLOCK(offset) ; i < 512 ; i++) {`
93			`if (i < 0)`
94			`i = 0;`
95			`if (i < INDIRECT_BLOCK(offset))`
96			`goto repeat;`
97			`ind = i+(unsigned short *) ind_bh->b_data;`
98			`tmp = *ind;`
99			`if (!tmp)`
100			`continue;`
101			`bh = get_hash_table(inode->i_dev,tmp,BLOCK_SIZE);`
102			`if (i < INDIRECT_BLOCK(offset)) {`
103			`brelse(bh);`
104			`goto repeat;`
105			`}`
106			`if ((bh && bh->b_count != 1) \|\| tmp != *ind) {`
107			`retry = 1;`
108			`brelse(bh);`
109			`continue;`
110			`}`
111			`*ind = 0;`
112			`mark_buffer_dirty(ind_bh, 1);`
113			`brelse(bh);`
114			`minix_free_block(inode->i_sb,tmp);`
115			`}`
116			`ind = (unsigned short *) ind_bh->b_data;`
117			`for (i = 0; i < 512; i++)`
118			`if (*(ind++))`
119			`break;`
120			`if (i >= 512)`
121			`if (ind_bh->b_count != 1)`
122			`retry = 1;`
123			`else {`
124			`tmp = *p;`
125			`*p = 0;`
126			`minix_free_block(inode->i_sb,tmp);`
127			`}`
128			`brelse(ind_bh);`
129			`return retry;`
130			`}`
131
132			`static int V1_trunc_dindirect(struct inode * inode, int offset, unsigned short *p)`
133			`{`
134			`int i, tmp;`
135			`struct buffer_head * dind_bh;`
136			`unsigned short * dind;`
137			`int retry = 0;`
138
139			`if (!(tmp = *p))`
140			`return 0;`
141			`dind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);`
142			`if (tmp != *p) {`
143			`brelse(dind_bh);`
144			`return 1;`
145			`}`
146			`if (!dind_bh) {`
147			`*p = 0;`
148			`return 0;`
149			`}`
150			`repeat:`
151			`for (i = V1_DINDIRECT_BLOCK(offset) ; i < 512 ; i ++) {`
152			`if (i < 0)`
153			`i = 0;`
154			`if (i < V1_DINDIRECT_BLOCK(offset))`
155			`goto repeat;`
156			`dind = i+(unsigned short *) dind_bh->b_data;`
157			`retry \|= V1_trunc_indirect(inode,offset+(i<<9),dind);`
158			`mark_buffer_dirty(dind_bh, 1);`
159			`}`
160			`dind = (unsigned short *) dind_bh->b_data;`
161			`for (i = 0; i < 512; i++)`
162			`if (*(dind++))`
163			`break;`
164			`if (i >= 512)`
165			`if (dind_bh->b_count != 1)`
166			`retry = 1;`
167			`else {`
168			`tmp = *p;`
169			`*p = 0;`
170			`inode->i_dirt = 1;`
171			`minix_free_block(inode->i_sb,tmp);`
172			`}`
173			`brelse(dind_bh);`
174			`return retry;`
175			`}`
176
177			`void V1_minix_truncate(struct inode * inode)`
178			`{`
179			`int retry;`
180
181			`if (!(S_ISREG(inode->i_mode) \|\| S_ISDIR(inode->i_mode) \|\|`
182			`S_ISLNK(inode->i_mode)))`
183			`return;`
184			`while (1) {`
185			`retry = V1_trunc_direct(inode);`
186			`retry \|= V1_trunc_indirect(inode, 7, inode->u.minix_i.u.i1_data + 7);`
187			`retry \|= V1_trunc_dindirect(inode, 7+512, inode->u.minix_i.u.i1_data + 8);`
188			`if (!retry)`
189			`break;`
190			`current->counter = 0;`
191			`schedule();`
192			`}`
193			`inode->i_mtime = inode->i_ctime = CURRENT_TIME;`
194			`inode->i_dirt = 1;`
195			`}`
196
197			`/*`
198			`* The functions for minix V2 fs truncation.`
199			`*/`
200			`static int V2_trunc_direct(struct inode * inode)`
201			`{`
202			`unsigned long * p;`
203			`struct buffer_head * bh;`
204			`int i, tmp;`
205			`int retry = 0;`
206
207			`repeat:`
208			`for (i = DIRECT_BLOCK ; i < 7 ; i++) {`
209			`p = (unsigned long *) inode->u.minix_i.u.i2_data + i;`
210			`if (!(tmp = *p))`
211			`continue;`
212			`bh = get_hash_table(inode->i_dev,tmp,BLOCK_SIZE);`
213			`if (i < DIRECT_BLOCK) {`
214			`brelse(bh);`
215			`goto repeat;`
216			`}`
217			`if ((bh && bh->b_count != 1) \|\| tmp != *p) {`
218			`retry = 1;`
219			`brelse(bh);`
220			`continue;`
221			`}`
222			`*p = 0;`
223			`inode->i_dirt = 1;`
224			`if (bh) {`
225			`mark_buffer_clean(bh);`
226			`brelse(bh);`
227			`}`
228			`minix_free_block(inode->i_sb,tmp);`
229			`}`
230			`return retry;`
231			`}`
232
233			`static int V2_trunc_indirect(struct inode * inode, int offset, unsigned long * p)`
234			`{`
235			`struct buffer_head * bh;`
236			`int i, tmp;`
237			`struct buffer_head * ind_bh;`
238			`unsigned long * ind;`
239			`int retry = 0;`
240
241			`tmp = *p;`
242			`if (!tmp)`
243			`return 0;`
244			`ind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);`
245			`if (tmp != *p) {`
246			`brelse(ind_bh);`
247			`return 1;`
248			`}`
249			`if (!ind_bh) {`
250			`*p = 0;`
251			`return 0;`
252			`}`
253			`repeat:`
254			`for (i = INDIRECT_BLOCK(offset) ; i < 256 ; i++) {`
255			`if (i < 0)`
256			`i = 0;`
257			`if (i < INDIRECT_BLOCK(offset))`
258			`goto repeat;`
259			`ind = i+(unsigned long *) ind_bh->b_data;`
260			`tmp = *ind;`
261			`if (!tmp)`
262			`continue;`
263			`bh = get_hash_table(inode->i_dev,tmp,BLOCK_SIZE);`
264			`if (i < INDIRECT_BLOCK(offset)) {`
265			`brelse(bh);`
266			`goto repeat;`
267			`}`
268			`if ((bh && bh->b_count != 1) \|\| tmp != *ind) {`
269			`retry = 1;`
270			`brelse(bh);`
271			`continue;`
272			`}`
273			`*ind = 0;`
274			`mark_buffer_dirty(ind_bh, 1);`
275			`brelse(bh);`
276			`minix_free_block(inode->i_sb,tmp);`
277			`}`
278			`ind = (unsigned long *) ind_bh->b_data;`
279			`for (i = 0; i < 256; i++)`
280			`if (*(ind++))`
281			`break;`
282			`if (i >= 256)`
283			`if (ind_bh->b_count != 1)`
284			`retry = 1;`
285			`else {`
286			`tmp = *p;`
287			`*p = 0;`
288			`minix_free_block(inode->i_sb,tmp);`
289			`}`
290			`brelse(ind_bh);`
291			`return retry;`
292			`}`
293
294			`static int V2_trunc_dindirect(struct inode * inode, int offset, unsigned long *p)`
295			`{`
296			`int i, tmp;`
297			`struct buffer_head * dind_bh;`
298			`unsigned long * dind;`
299			`int retry = 0;`
300
301			`if (!(tmp = *p))`
302			`return 0;`
303			`dind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);`
304			`if (tmp != *p) {`
305			`brelse(dind_bh);`
306			`return 1;`
307			`}`
308			`if (!dind_bh) {`
309			`*p = 0;`
310			`return 0;`
311			`}`
312			`repeat:`
313			`for (i = V2_DINDIRECT_BLOCK(offset) ; i < 256 ; i ++) {`
314			`if (i < 0)`
315			`i = 0;`
316			`if (i < V2_DINDIRECT_BLOCK(offset))`
317			`goto repeat;`
318			`dind = i+(unsigned long *) dind_bh->b_data;`
319			`retry \|= V2_trunc_indirect(inode,offset+(i<<8),dind);`
320			`mark_buffer_dirty(dind_bh, 1);`
321			`}`
322			`dind = (unsigned long *) dind_bh->b_data;`
323			`for (i = 0; i < 256; i++)`
324			`if (*(dind++))`
325			`break;`
326			`if (i >= 256)`
327			`if (dind_bh->b_count != 1)`
328			`retry = 1;`
329			`else {`
330			`tmp = *p;`
331			`*p = 0;`
332			`inode->i_dirt = 1;`
333			`minix_free_block(inode->i_sb,tmp);`
334			`}`
335			`brelse(dind_bh);`
336			`return retry;`
337			`}`
338
339			`static int V2_trunc_tindirect(struct inode * inode, int offset, unsigned long * p)`
340			`{`
341			`int i, tmp;`
342			`struct buffer_head * tind_bh;`
343			`unsigned long * tind;`
344			`int retry = 0;`
345
346			`if (!(tmp = *p))`
347			`return 0;`
348			`tind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);`
349			`if (tmp != *p) {`
350			`brelse(tind_bh);`
351			`return 1;`
352			`}`
353			`if (!tind_bh) {`
354			`*p = 0;`
355			`return 0;`
356			`}`
357			`repeat:`
358			`for (i = TINDIRECT_BLOCK(offset) ; i < 256 ; i ++) {`
359			`if (i < 0)`
360			`i = 0;`
361			`if (i < TINDIRECT_BLOCK(offset))`
362			`goto repeat;`
363			`tind = i+(unsigned long *) tind_bh->b_data;`
364			`retry \|= V2_trunc_dindirect(inode,offset+(i<<8),tind);`
365			`mark_buffer_dirty(tind_bh, 1);`
366			`}`
367			`tind = (unsigned long *) tind_bh->b_data;`
368			`for (i = 0; i < 256; i++)`
369			`if (*(tind++))`
370			`break;`
371			`if (i >= 256)`
372			`if (tind_bh->b_count != 1)`
373			`retry = 1;`
374			`else {`
375			`tmp = *p;`
376			`*p = 0;`
377			`inode->i_dirt = 1;`
378			`minix_free_block(inode->i_sb,tmp);`
379			`}`
380			`brelse(tind_bh);`
381			`return retry;`
382			`}`
383
384			`static void V2_minix_truncate(struct inode * inode)`
385			`{`
386			`int retry;`
387
388			`if (!(S_ISREG(inode->i_mode) \|\| S_ISDIR(inode->i_mode) \|\|`
389			`S_ISLNK(inode->i_mode)))`
390			`return;`
391			`while (1) {`
392			`retry = V2_trunc_direct(inode);`
393			`retry \|= V2_trunc_indirect(inode,7,`
394			`(unsigned long *) inode->u.minix_i.u.i2_data + 7);`
395			`retry \|= V2_trunc_dindirect(inode, 7+256,`
396			`(unsigned long *) inode->u.minix_i.u.i2_data + 8);`
397			`retry \|= V2_trunc_tindirect(inode, 7+256+256*256,`
398			`(unsigned long *) inode->u.minix_i.u.i2_data + 9);`
399			`if (!retry)`
400			`break;`
401			`current->counter = 0;`
402			`schedule();`
403			`}`
404			`inode->i_mtime = inode->i_ctime = CURRENT_TIME;`
405			`inode->i_dirt = 1;`
406			`}`
407
408			`/*`
409			`* The function that is called for file truncation.`
410			`*/`
411			`void minix_truncate(struct inode * inode)`
412			`{`
413			`if (INODE_VERSION(inode) == MINIX_V1)`
414			`V1_minix_truncate(inode);`
415			`else`
416			`V2_minix_truncate(inode);`
417			`}`