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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [fs/] [ext/] [truncate.c] - Blame information for rev 1777

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/*
 *  linux/fs/ext/truncate.c
 *
 *  Copyright (C) 1992  Remy Card (card@masi.ibp.fr)
 *
 *  from
 *
 *  linux/fs/minix/truncate.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */
 
#include <linux/sched.h>
#include <linux/ext_fs.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/errno.h>
 
/*
 * 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.
 */
 
static int trunc_direct(struct inode * inode)
{
        int i, tmp;
        unsigned long * p;
        struct buffer_head * bh;
        int retry = 0;
#define DIRECT_BLOCK ((inode->i_size + 1023) >> 10)
 
repeat:
        for (i = DIRECT_BLOCK ; i < 9 ; i++) {
                p = inode->u.ext_i.i_data+i;
                if (!(tmp = *p))
                        continue;
                bh = getblk(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;
                brelse(bh);
                ext_free_block(inode->i_sb,tmp);
        }
        return retry;
}
 
static int trunc_indirect(struct inode * inode, int offset, unsigned long * p)
{
        int i, tmp;
        struct buffer_head * bh;
        struct buffer_head * ind_bh;
        unsigned long * ind;
        int retry = 0;
#define INDIRECT_BLOCK (DIRECT_BLOCK-offset)
 
        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 ; i < 256 ; i++) {
                if (i < 0)
                        i = 0;
                if (i < INDIRECT_BLOCK)
                        goto repeat;
                ind = i+(unsigned long *) ind_bh->b_data;
                tmp = *ind;
                if (!tmp)
                        continue;
                bh = getblk(inode->i_dev,tmp,BLOCK_SIZE);
                if (i < INDIRECT_BLOCK) {
                        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);
                ext_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;
                        inode->i_dirt = 1;
                        ext_free_block(inode->i_sb,tmp);
                }
        brelse(ind_bh);
        return retry;
}
 
static int trunc_dindirect(struct inode * inode, int offset, unsigned long * p)
{
        int i,tmp;
        struct buffer_head * dind_bh;
        unsigned long * dind;
        int retry = 0;
#define DINDIRECT_BLOCK ((DIRECT_BLOCK-offset)>>8)
 
        tmp = *p;
        if (!tmp)
                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 = DINDIRECT_BLOCK ; i < 256 ; i ++) {
                if (i < 0)
                        i = 0;
                if (i < DINDIRECT_BLOCK)
                        goto repeat;
                dind = i+(unsigned long *) dind_bh->b_data;
                tmp = *dind;
                if (!tmp)
                        continue;
                retry |= 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;
                        ext_free_block(inode->i_sb,tmp);
                }
        brelse(dind_bh);
        return retry;
}
 
static int trunc_tindirect(struct inode * inode)
{
        int i,tmp;
        struct buffer_head * tind_bh;
        unsigned long * tind, * p;
        int retry = 0;
#define TINDIRECT_BLOCK ((DIRECT_BLOCK-(256*256+256+9))>>16)
 
        p = inode->u.ext_i.i_data+11;
        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 ; i < 256 ; i ++) {
                if (i < 0)
                        i = 0;
                if (i < TINDIRECT_BLOCK)
                        goto repeat;
                tind = i+(unsigned long *) tind_bh->b_data;
                retry |= trunc_dindirect(inode,9+256+256*256+(i<<16),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;
                        ext_free_block(inode->i_sb,tmp);
                }
        brelse(tind_bh);
        return retry;
}
 
void ext_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 = trunc_direct(inode);
                retry |= trunc_indirect(inode,9,inode->u.ext_i.i_data+9);
                retry |= trunc_dindirect(inode,9+256,inode->u.ext_i.i_data+10);
                retry |= trunc_tindirect(inode);
                if (!retry)
                        break;
                current->counter = 0;
                schedule();
        }
        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
        inode->i_dirt = 1;
}
 
/*
 * Called when a inode is released. Note that this is different
 * from ext_open: open gets called at every open, but release
 * gets called only when /all/ the files are closed.
 */
void ext_release(struct inode * inode, struct file * filp)
{
        printk("ext_release not implemented\n");
}

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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [fs/] [ext/] [truncate.c] - Blame information for rev 1777

Line No.	Rev	Author	Line
1	1628	jcastillo	`/*`
2			`* linux/fs/ext/truncate.c`
3			`*`
4			`* Copyright (C) 1992 Remy Card (card@masi.ibp.fr)`
5			`*`
6			`* from`
7			`*`
8			`* linux/fs/minix/truncate.c`
9			`*`
10			`* Copyright (C) 1991, 1992 Linus Torvalds`
11			`*/`
12
13			`#include <linux/sched.h>`
14			`#include <linux/ext_fs.h>`
15			`#include <linux/stat.h>`
16			`#include <linux/fcntl.h>`
17			`#include <linux/errno.h>`
18
19			`/*`
20			`* Truncate has the most races in the whole filesystem: coding it is`
21			`* a pain in the a**. Especially as I don't do any locking...`
22			`*`
23			`* The code may look a bit weird, but that's just because I've tried to`
24			`* handle things like file-size changes in a somewhat graceful manner.`
25			`* Anyway, truncating a file at the same time somebody else writes to it`
26			`* is likely to result in pretty weird behaviour...`
27			`*`
28			`* The new code handles normal truncates (size = 0) as well as the more`
29			`* general case (size = XXX). I hope.`
30			`*/`
31
32			`static int trunc_direct(struct inode * inode)`
33			`{`
34			`int i, tmp;`
35			`unsigned long * p;`
36			`struct buffer_head * bh;`
37			`int retry = 0;`
38			`#define DIRECT_BLOCK ((inode->i_size + 1023) >> 10)`
39
40			`repeat:`
41			`for (i = DIRECT_BLOCK ; i < 9 ; i++) {`
42			`p = inode->u.ext_i.i_data+i;`
43			`if (!(tmp = *p))`
44			`continue;`
45			`bh = getblk(inode->i_dev,tmp,BLOCK_SIZE);`
46			`if (i < DIRECT_BLOCK) {`
47			`brelse(bh);`
48			`goto repeat;`
49			`}`
50			`if ((bh && bh->b_count != 1) \|\| tmp != *p) {`
51			`retry = 1;`
52			`brelse(bh);`
53			`continue;`
54			`}`
55			`*p = 0;`
56			`inode->i_dirt = 1;`
57			`brelse(bh);`
58			`ext_free_block(inode->i_sb,tmp);`
59			`}`
60			`return retry;`
61			`}`
62
63			`static int trunc_indirect(struct inode * inode, int offset, unsigned long * p)`
64			`{`
65			`int i, tmp;`
66			`struct buffer_head * bh;`
67			`struct buffer_head * ind_bh;`
68			`unsigned long * ind;`
69			`int retry = 0;`
70			`#define INDIRECT_BLOCK (DIRECT_BLOCK-offset)`
71
72			`tmp = *p;`
73			`if (!tmp)`
74			`return 0;`
75			`ind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);`
76			`if (tmp != *p) {`
77			`brelse(ind_bh);`
78			`return 1;`
79			`}`
80			`if (!ind_bh) {`
81			`*p = 0;`
82			`return 0;`
83			`}`
84			`repeat:`
85			`for (i = INDIRECT_BLOCK ; i < 256 ; i++) {`
86			`if (i < 0)`
87			`i = 0;`
88			`if (i < INDIRECT_BLOCK)`
89			`goto repeat;`
90			`ind = i+(unsigned long *) ind_bh->b_data;`
91			`tmp = *ind;`
92			`if (!tmp)`
93			`continue;`
94			`bh = getblk(inode->i_dev,tmp,BLOCK_SIZE);`
95			`if (i < INDIRECT_BLOCK) {`
96			`brelse(bh);`
97			`goto repeat;`
98			`}`
99			`if ((bh && bh->b_count != 1) \|\| tmp != *ind) {`
100			`retry = 1;`
101			`brelse(bh);`
102			`continue;`
103			`}`
104			`*ind = 0;`
105			`mark_buffer_dirty(ind_bh, 1);`
106			`brelse(bh);`
107			`ext_free_block(inode->i_sb,tmp);`
108			`}`
109			`ind = (unsigned long *) ind_bh->b_data;`
110			`for (i = 0; i < 256; i++)`
111			`if (*(ind++))`
112			`break;`
113			`if (i >= 256)`
114			`if (ind_bh->b_count != 1)`
115			`retry = 1;`
116			`else {`
117			`tmp = *p;`
118			`*p = 0;`
119			`inode->i_dirt = 1;`
120			`ext_free_block(inode->i_sb,tmp);`
121			`}`
122			`brelse(ind_bh);`
123			`return retry;`
124			`}`
125
126			`static int trunc_dindirect(struct inode * inode, int offset, unsigned long * p)`
127			`{`
128			`int i,tmp;`
129			`struct buffer_head * dind_bh;`
130			`unsigned long * dind;`
131			`int retry = 0;`
132			`#define DINDIRECT_BLOCK ((DIRECT_BLOCK-offset)>>8)`
133
134			`tmp = *p;`
135			`if (!tmp)`
136			`return 0;`
137			`dind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);`
138			`if (tmp != *p) {`
139			`brelse(dind_bh);`
140			`return 1;`
141			`}`
142			`if (!dind_bh) {`
143			`*p = 0;`
144			`return 0;`
145			`}`
146			`repeat:`
147			`for (i = DINDIRECT_BLOCK ; i < 256 ; i ++) {`
148			`if (i < 0)`
149			`i = 0;`
150			`if (i < DINDIRECT_BLOCK)`
151			`goto repeat;`
152			`dind = i+(unsigned long *) dind_bh->b_data;`
153			`tmp = *dind;`
154			`if (!tmp)`
155			`continue;`
156			`retry \|= trunc_indirect(inode,offset+(i<<8),dind);`
157			`mark_buffer_dirty(dind_bh, 1);`
158			`}`
159			`dind = (unsigned long *) dind_bh->b_data;`
160			`for (i = 0; i < 256; i++)`
161			`if (*(dind++))`
162			`break;`
163			`if (i >= 256)`
164			`if (dind_bh->b_count != 1)`
165			`retry = 1;`
166			`else {`
167			`tmp = *p;`
168			`*p = 0;`
169			`inode->i_dirt = 1;`
170			`ext_free_block(inode->i_sb,tmp);`
171			`}`
172			`brelse(dind_bh);`
173			`return retry;`
174			`}`
175
176			`static int trunc_tindirect(struct inode * inode)`
177			`{`
178			`int i,tmp;`
179			`struct buffer_head * tind_bh;`
180			`unsigned long * tind, * p;`
181			`int retry = 0;`
182			`#define TINDIRECT_BLOCK ((DIRECT_BLOCK-(256*256+256+9))>>16)`
183
184			`p = inode->u.ext_i.i_data+11;`
185			`if (!(tmp = *p))`
186			`return 0;`
187			`tind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);`
188			`if (tmp != *p) {`
189			`brelse(tind_bh);`
190			`return 1;`
191			`}`
192			`if (!tind_bh) {`
193			`*p = 0;`
194			`return 0;`
195			`}`
196			`repeat:`
197			`for (i = TINDIRECT_BLOCK ; i < 256 ; i ++) {`
198			`if (i < 0)`
199			`i = 0;`
200			`if (i < TINDIRECT_BLOCK)`
201			`goto repeat;`
202			`tind = i+(unsigned long *) tind_bh->b_data;`
203			`retry \|= trunc_dindirect(inode,9+256+256*256+(i<<16),tind);`
204			`mark_buffer_dirty(tind_bh, 1);`
205			`}`
206			`tind = (unsigned long *) tind_bh->b_data;`
207			`for (i = 0; i < 256; i++)`
208			`if (*(tind++))`
209			`break;`
210			`if (i >= 256)`
211			`if (tind_bh->b_count != 1)`
212			`retry = 1;`
213			`else {`
214			`tmp = *p;`
215			`*p = 0;`
216			`inode->i_dirt = 1;`
217			`ext_free_block(inode->i_sb,tmp);`
218			`}`
219			`brelse(tind_bh);`
220			`return retry;`
221			`}`
222
223			`void ext_truncate(struct inode * inode)`
224			`{`
225			`int retry;`
226
227			`if (!(S_ISREG(inode->i_mode) \|\| S_ISDIR(inode->i_mode) \|\|`
228			`S_ISLNK(inode->i_mode)))`
229			`return;`
230			`while (1) {`
231			`retry = trunc_direct(inode);`
232			`retry \|= trunc_indirect(inode,9,inode->u.ext_i.i_data+9);`
233			`retry \|= trunc_dindirect(inode,9+256,inode->u.ext_i.i_data+10);`
234			`retry \|= trunc_tindirect(inode);`
235			`if (!retry)`
236			`break;`
237			`current->counter = 0;`
238			`schedule();`
239			`}`
240			`inode->i_mtime = inode->i_ctime = CURRENT_TIME;`
241			`inode->i_dirt = 1;`
242			`}`
243
244			`/*`
245			`* Called when a inode is released. Note that this is different`
246			`* from ext_open: open gets called at every open, but release`
247			`* gets called only when /all/ the files are closed.`
248			`*/`
249			`void ext_release(struct inode * inode, struct file * filp)`
250			`{`
251			`printk("ext_release not implemented\n");`
252			`}`