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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [fs/] [ext/] [file.c] - Blame information for rev 1765

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/*
 *  linux/fs/ext/file.c
 *
 *  Copyright (C) 1992 Remy Card (card@masi.ibp.fr)
 *
 *  from
 *
 *  linux/fs/minix/file.c
 *
 *  Copyright (C) 1991, 1992 Linus Torvalds
 *
 *  ext regular file handling primitives
 */
 
#include <asm/segment.h>
#include <asm/system.h>
 
#include <linux/sched.h>
#include <linux/ext_fs.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/locks.h>
#include <linux/pagemap.h>
 
#define NBUF    32
 
#define MIN(a,b) (((a)<(b))?(a):(b))
#define MAX(a,b) (((a)>(b))?(a):(b))
 
#include <linux/fs.h>
#include <linux/ext_fs.h>
 
static int ext_file_read(struct inode *, struct file *, char *, int);
static int ext_file_write(struct inode *, struct file *, const char *, int);
 
/*
 * We have mostly NULL's here: the current defaults are ok for
 * the ext filesystem.
 */
static struct file_operations ext_file_operations = {
        NULL,                   /* lseek - default */
        ext_file_read,  /* read */
        ext_file_write, /* write */
        NULL,                   /* readdir - bad */
        NULL,                   /* select - default */
        NULL,                   /* ioctl - default */
        generic_file_mmap,      /* mmap */
        NULL,                   /* no special open is needed */
        NULL,                   /* release */
        ext_sync_file                   /* fsync */
};
 
struct inode_operations ext_file_inode_operations = {
        &ext_file_operations,   /* default file operations */
        NULL,                   /* create */
        NULL,                   /* lookup */
        NULL,                   /* link */
        NULL,                   /* unlink */
        NULL,                   /* symlink */
        NULL,                   /* mkdir */
        NULL,                   /* rmdir */
        NULL,                   /* mknod */
        NULL,                   /* rename */
        NULL,                   /* readlink */
        NULL,                   /* follow_link */
        generic_readpage,       /* readpage */
        NULL,                   /* writepage */
        ext_bmap,               /* bmap */
        ext_truncate,           /* truncate */
        NULL                    /* permission */
};
 
static int ext_file_read(struct inode * inode, struct file * filp, char * buf, int count)
{
        int read,left,chars;
        int block, blocks, offset;
        int bhrequest, uptodate;
        struct buffer_head ** bhb, ** bhe;
        struct buffer_head * bhreq[NBUF];
        struct buffer_head * buflist[NBUF];
        unsigned int size;
 
        if (!inode) {
                printk("ext_file_read: inode = NULL\n");
                return -EINVAL;
        }
        if (!S_ISREG(inode->i_mode)) {
                printk("ext_file_read: mode = %07o\n",inode->i_mode);
                return -EINVAL;
        }
        offset = filp->f_pos;
        size = inode->i_size;
        if (offset > size)
                left = 0;
        else
                left = size - offset;
        if (left > count)
                left = count;
        if (left <= 0)
                return 0;
        read = 0;
        block = offset >> BLOCK_SIZE_BITS;
        offset &= BLOCK_SIZE-1;
        size = (size + (BLOCK_SIZE-1)) >> BLOCK_SIZE_BITS;
        blocks = (left + offset + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
        bhb = bhe = buflist;
        if (filp->f_reada) {
                if(blocks < read_ahead[MAJOR(inode->i_dev)] / (BLOCK_SIZE >> 9))
                  blocks = read_ahead[MAJOR(inode->i_dev)] / (BLOCK_SIZE >> 9);
                if (block + blocks > size)
                        blocks = size - block;
        }
 
        /* We do this in a two stage process.  We first try to request
           as many blocks as we can, then we wait for the first one to
           complete, and then we try to wrap up as many as are actually
           done.  This routine is rather generic, in that it can be used
           in a filesystem by substituting the appropriate function in
           for getblk.
 
           This routine is optimized to make maximum use of the various
           buffers and caches. */
 
        do {
                bhrequest = 0;
                uptodate = 1;
                while (blocks) {
                        --blocks;
                        *bhb = ext_getblk(inode, block++, 0);
                        if (*bhb && !buffer_uptodate(*bhb)) {
                                uptodate = 0;
                                bhreq[bhrequest++] = *bhb;
                        }
 
                        if (++bhb == &buflist[NBUF])
                                bhb = buflist;
 
                        /* If the block we have on hand is uptodate, go ahead
                           and complete processing. */
                        if (uptodate)
                                break;
                        if (bhb == bhe)
                                break;
                }
 
                /* Now request them all */
                if (bhrequest)
                        ll_rw_block(READ, bhrequest, bhreq);
 
                do { /* Finish off all I/O that has actually completed */
                        if (*bhe) {
                                wait_on_buffer(*bhe);
                                if (!buffer_uptodate(*bhe)) {   /* read error? */
                                        brelse(*bhe);
                                        if (++bhe == &buflist[NBUF])
                                          bhe = buflist;
                                        left = 0;
                                        break;
                                }
                        }
                        if (left < BLOCK_SIZE - offset)
                                chars = left;
                        else
                                chars = BLOCK_SIZE - offset;
                        filp->f_pos += chars;
                        left -= chars;
                        read += chars;
                        if (*bhe) {
                                memcpy_tofs(buf,offset+(*bhe)->b_data,chars);
                                brelse(*bhe);
                                buf += chars;
                        } else {
                                while (chars-->0)
                                        put_user(0,buf++);
                        }
                        offset = 0;
                        if (++bhe == &buflist[NBUF])
                                bhe = buflist;
                } while (left > 0 && bhe != bhb && (!*bhe || !buffer_locked(*bhe)));
        } while (left > 0);
 
/* Release the read-ahead blocks */
        while (bhe != bhb) {
                brelse(*bhe);
                if (++bhe == &buflist[NBUF])
                        bhe = buflist;
        };
        if (!read)
                return -EIO;
        filp->f_reada = 1;
        if (!IS_RDONLY(inode)) {
                inode->i_atime = CURRENT_TIME;
                inode->i_dirt = 1;
        }
        return read;
}
 
static int ext_file_write(struct inode * inode, struct file * filp, const char * buf, int count)
{
        off_t pos;
        int written,c;
        struct buffer_head * bh;
        char * p;
 
        if (!inode) {
                printk("ext_file_write: inode = NULL\n");
                return -EINVAL;
        }
        if (!S_ISREG(inode->i_mode)) {
                printk("ext_file_write: mode = %07o\n",inode->i_mode);
                return -EINVAL;
        }
/*
 * ok, append may not work when many processes are writing at the same time
 * but so what. That way leads to madness anyway.
 */
        if (filp->f_flags & O_APPEND)
                pos = inode->i_size;
        else
                pos = filp->f_pos;
        written = 0;
        while (written<count) {
                bh = ext_getblk(inode,pos/BLOCK_SIZE,1);
                if (!bh) {
                        if (!written)
                                written = -ENOSPC;
                        break;
                }
                c = BLOCK_SIZE - (pos % BLOCK_SIZE);
                if (c > count-written)
                        c = count-written;
                if (c != BLOCK_SIZE && !buffer_uptodate(bh)) {
                        ll_rw_block(READ, 1, &bh);
                        wait_on_buffer(bh);
                        if (!buffer_uptodate(bh)) {
                                brelse(bh);
                                if (!written)
                                        written = -EIO;
                                break;
                        }
                }
                p = (pos % BLOCK_SIZE) + bh->b_data;
                memcpy_fromfs(p,buf,c);
                update_vm_cache(inode, pos, p, c);
                pos += c;
                if (pos > inode->i_size) {
                        inode->i_size = pos;
                        inode->i_dirt = 1;
                }
                written += c;
                buf += c;
                mark_buffer_uptodate(bh, 1);
                mark_buffer_dirty(bh, 0);
                brelse(bh);
        }
        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
        filp->f_pos = pos;
        inode->i_dirt = 1;
        return written;
}

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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [fs/] [ext/] [file.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	1628	jcastillo	`/*`
2			`* linux/fs/ext/file.c`
3			`*`
4			`* Copyright (C) 1992 Remy Card (card@masi.ibp.fr)`
5			`*`
6			`* from`
7			`*`
8			`* linux/fs/minix/file.c`
9			`*`
10			`* Copyright (C) 1991, 1992 Linus Torvalds`
11			`*`
12			`* ext regular file handling primitives`
13			`*/`
14
15			`#include <asm/segment.h>`
16			`#include <asm/system.h>`
17
18			`#include <linux/sched.h>`
19			`#include <linux/ext_fs.h>`
20			`#include <linux/kernel.h>`
21			`#include <linux/errno.h>`
22			`#include <linux/fcntl.h>`
23			`#include <linux/stat.h>`
24			`#include <linux/locks.h>`
25			`#include <linux/pagemap.h>`
26
27			`#define NBUF 32`
28
29			`#define MIN(a,b) (((a)<(b))?(a):(b))`
30			`#define MAX(a,b) (((a)>(b))?(a):(b))`
31
32			`#include <linux/fs.h>`
33			`#include <linux/ext_fs.h>`
34
35			`static int ext_file_read(struct inode , struct file , char *, int);`
36			`static int ext_file_write(struct inode , struct file , const char *, int);`
37
38			`/*`
39			`* We have mostly NULL's here: the current defaults are ok for`
40			`* the ext filesystem.`
41			`*/`
42			`static struct file_operations ext_file_operations = {`
43			`NULL, /* lseek - default */`
44			`ext_file_read, /* read */`
45			`ext_file_write, /* write */`
46			`NULL, /* readdir - bad */`
47			`NULL, /* select - default */`
48			`NULL, /* ioctl - default */`
49			`generic_file_mmap, /* mmap */`
50			`NULL, /* no special open is needed */`
51			`NULL, /* release */`
52			`ext_sync_file /* fsync */`
53			`};`
54
55			`struct inode_operations ext_file_inode_operations = {`
56			`&ext_file_operations, /* default file operations */`
57			`NULL, /* create */`
58			`NULL, /* lookup */`
59			`NULL, /* link */`
60			`NULL, /* unlink */`
61			`NULL, /* symlink */`
62			`NULL, /* mkdir */`
63			`NULL, /* rmdir */`
64			`NULL, /* mknod */`
65			`NULL, /* rename */`
66			`NULL, /* readlink */`
67			`NULL, /* follow_link */`
68			`generic_readpage, /* readpage */`
69			`NULL, /* writepage */`
70			`ext_bmap, /* bmap */`
71			`ext_truncate, /* truncate */`
72			`NULL /* permission */`
73			`};`
74
75			`static int ext_file_read(struct inode * inode, struct file * filp, char * buf, int count)`
76			`{`
77			`int read,left,chars;`
78			`int block, blocks, offset;`
79			`int bhrequest, uptodate;`
80			`struct buffer_head bhb, bhe;`
81			`struct buffer_head * bhreq[NBUF];`
82			`struct buffer_head * buflist[NBUF];`
83			`unsigned int size;`
84
85			`if (!inode) {`
86			`printk("ext_file_read: inode = NULL\n");`
87			`return -EINVAL;`
88			`}`
89			`if (!S_ISREG(inode->i_mode)) {`
90			`printk("ext_file_read: mode = %07o\n",inode->i_mode);`
91			`return -EINVAL;`
92			`}`
93			`offset = filp->f_pos;`
94			`size = inode->i_size;`
95			`if (offset > size)`
96			`left = 0;`
97			`else`
98			`left = size - offset;`
99			`if (left > count)`
100			`left = count;`
101			`if (left <= 0)`
102			`return 0;`
103			`read = 0;`
104			`block = offset >> BLOCK_SIZE_BITS;`
105			`offset &= BLOCK_SIZE-1;`
106			`size = (size + (BLOCK_SIZE-1)) >> BLOCK_SIZE_BITS;`
107			`blocks = (left + offset + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;`
108			`bhb = bhe = buflist;`
109			`if (filp->f_reada) {`
110			`if(blocks < read_ahead[MAJOR(inode->i_dev)] / (BLOCK_SIZE >> 9))`
111			`blocks = read_ahead[MAJOR(inode->i_dev)] / (BLOCK_SIZE >> 9);`
112			`if (block + blocks > size)`
113			`blocks = size - block;`
114			`}`
115
116			`/* We do this in a two stage process. We first try to request`
117			`as many blocks as we can, then we wait for the first one to`
118			`complete, and then we try to wrap up as many as are actually`
119			`done. This routine is rather generic, in that it can be used`
120			`in a filesystem by substituting the appropriate function in`
121			`for getblk.`
122
123			`This routine is optimized to make maximum use of the various`
124			`buffers and caches. */`
125
126			`do {`
127			`bhrequest = 0;`
128			`uptodate = 1;`
129			`while (blocks) {`
130			`--blocks;`
131			`*bhb = ext_getblk(inode, block++, 0);`
132			`if (bhb && !buffer_uptodate(bhb)) {`
133			`uptodate = 0;`
134			`bhreq[bhrequest++] = *bhb;`
135			`}`
136
137			`if (++bhb == &buflist[NBUF])`
138			`bhb = buflist;`
139
140			`/* If the block we have on hand is uptodate, go ahead`
141			`and complete processing. */`
142			`if (uptodate)`
143			`break;`
144			`if (bhb == bhe)`
145			`break;`
146			`}`
147
148			`/* Now request them all */`
149			`if (bhrequest)`
150			`ll_rw_block(READ, bhrequest, bhreq);`
151
152			`do { /* Finish off all I/O that has actually completed */`
153			`if (*bhe) {`
154			`wait_on_buffer(*bhe);`
155			`if (!buffer_uptodate(bhe)) { / read error? */`
156			`brelse(*bhe);`
157			`if (++bhe == &buflist[NBUF])`
158			`bhe = buflist;`
159			`left = 0;`
160			`break;`
161			`}`
162			`}`
163			`if (left < BLOCK_SIZE - offset)`
164			`chars = left;`
165			`else`
166			`chars = BLOCK_SIZE - offset;`
167			`filp->f_pos += chars;`
168			`left -= chars;`
169			`read += chars;`
170			`if (*bhe) {`
171			`memcpy_tofs(buf,offset+(*bhe)->b_data,chars);`
172			`brelse(*bhe);`
173			`buf += chars;`
174			`} else {`
175			`while (chars-->0)`
176			`put_user(0,buf++);`
177			`}`
178			`offset = 0;`
179			`if (++bhe == &buflist[NBUF])`
180			`bhe = buflist;`
181			`} while (left > 0 && bhe != bhb && (!bhe \|\| !buffer_locked(bhe)));`
182			`} while (left > 0);`
183
184			`/* Release the read-ahead blocks */`
185			`while (bhe != bhb) {`
186			`brelse(*bhe);`
187			`if (++bhe == &buflist[NBUF])`
188			`bhe = buflist;`
189			`};`
190			`if (!read)`
191			`return -EIO;`
192			`filp->f_reada = 1;`
193			`if (!IS_RDONLY(inode)) {`
194			`inode->i_atime = CURRENT_TIME;`
195			`inode->i_dirt = 1;`
196			`}`
197			`return read;`
198			`}`
199
200			`static int ext_file_write(struct inode * inode, struct file * filp, const char * buf, int count)`
201			`{`
202			`off_t pos;`
203			`int written,c;`
204			`struct buffer_head * bh;`
205			`char * p;`
206
207			`if (!inode) {`
208			`printk("ext_file_write: inode = NULL\n");`
209			`return -EINVAL;`
210			`}`
211			`if (!S_ISREG(inode->i_mode)) {`
212			`printk("ext_file_write: mode = %07o\n",inode->i_mode);`
213			`return -EINVAL;`
214			`}`
215			`/*`
216			`* ok, append may not work when many processes are writing at the same time`
217			`* but so what. That way leads to madness anyway.`
218			`*/`
219			`if (filp->f_flags & O_APPEND)`
220			`pos = inode->i_size;`
221			`else`
222			`pos = filp->f_pos;`
223			`written = 0;`
224			`while (written<count) {`
225			`bh = ext_getblk(inode,pos/BLOCK_SIZE,1);`
226			`if (!bh) {`
227			`if (!written)`
228			`written = -ENOSPC;`
229			`break;`
230			`}`
231			`c = BLOCK_SIZE - (pos % BLOCK_SIZE);`
232			`if (c > count-written)`
233			`c = count-written;`
234			`if (c != BLOCK_SIZE && !buffer_uptodate(bh)) {`
235			`ll_rw_block(READ, 1, &bh);`
236			`wait_on_buffer(bh);`
237			`if (!buffer_uptodate(bh)) {`
238			`brelse(bh);`
239			`if (!written)`
240			`written = -EIO;`
241			`break;`
242			`}`
243			`}`
244			`p = (pos % BLOCK_SIZE) + bh->b_data;`
245			`memcpy_fromfs(p,buf,c);`
246			`update_vm_cache(inode, pos, p, c);`
247			`pos += c;`
248			`if (pos > inode->i_size) {`
249			`inode->i_size = pos;`
250			`inode->i_dirt = 1;`
251			`}`
252			`written += c;`
253			`buf += c;`
254			`mark_buffer_uptodate(bh, 1);`
255			`mark_buffer_dirty(bh, 0);`
256			`brelse(bh);`
257			`}`
258			`inode->i_mtime = inode->i_ctime = CURRENT_TIME;`
259			`filp->f_pos = pos;`
260			`inode->i_dirt = 1;`
261			`return written;`
262			`}`