Rev 684 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2 | pj | 1 | |
| 1063 | tullio | 2 | /* |
| 3 | * This program is free software; you can redistribute it and/or modify |
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| 4 | * it under the terms of the GNU General Public License as published by |
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| 5 | * the Free Software Foundation; either version 2 of the License, or |
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| 6 | * (at your option) any later version. |
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| 7 | * |
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| 8 | * This program is distributed in the hope that it will be useful, |
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| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 11 | * GNU General Public License for more details. |
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| 12 | * |
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| 13 | * You should have received a copy of the GNU General Public License |
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| 14 | * along with this program; if not, write to the Free Software |
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| 15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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| 16 | * |
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| 17 | */ |
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| 18 | |||
| 2 | pj | 19 | #include <fs/types.h> |
| 20 | #include <fs/errno.h> |
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| 21 | #include <fs/task.h> |
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| 22 | #include <fs/maccess.h> |
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| 23 | #include <fs/fcntl.h> |
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| 24 | |||
| 25 | #include "file.h" |
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| 26 | #include "inode.h" |
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| 27 | #include "dentry.h" |
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| 28 | #include "fileop.h" |
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| 29 | #include "rwlock.h" |
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| 30 | #include "fs.h" |
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| 31 | |||
| 32 | #define EBOH EIO |
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| 33 | |||
| 34 | /* temporary: for console i/o */ |
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| 35 | #include <ll/i386/cons.h> |
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| 36 | static int __getch(int flag) |
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| 37 | { |
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| 684 | giacomo | 38 | |
| 39 | return 0; |
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| 40 | |||
| 2 | pj | 41 | } |
| 42 | |||
| 43 | __ssize_t k_read(int fd, __ptr_t buf, __ssize_t nbytes) |
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| 44 | { |
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| 45 | __pid_t pid; |
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| 46 | __ssize_t sz; |
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| 47 | |||
| 48 | call_to_fs(); |
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| 49 | |||
| 50 | /* TO FIX! */ |
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| 51 | if (fd>=0&&fd<=2) { |
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| 52 | __ssize_t x; |
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| 53 | int ret,ch; |
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| 54 | char *c; |
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| 55 | |||
| 56 | //printk(KERN_INFO "reading from console"); |
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| 57 | |||
| 58 | /* WARNIG buf is a pointer into user-space |
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| 59 | * we are using it without cast |
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| 60 | */ |
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| 61 | |||
| 62 | /* WARNIG there is a blocking call... |
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| 63 | * the system can go down if it is blocked! |
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| 64 | */ |
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| 65 | |||
| 66 | if (fd!=0) return_from_fs(-EBADF); |
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| 67 | |||
| 68 | c=(char*)buf; |
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| 69 | x=0; |
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| 70 | while (x<nbytes) { |
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| 71 | ch=__getch(NON_BLOCK); |
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| 72 | if (ch!=-1) *c++=ch; |
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| 73 | else { |
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| 74 | if (x>0) break; |
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| 75 | release_sys_call(); |
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| 76 | ch=__getch(BLOCK); |
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| 77 | ret=reacquire_sys_call(); |
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| 78 | if (ret) return -ENOSYS; |
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| 79 | *c++=ch; |
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| 80 | } |
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| 81 | x++; |
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| 82 | cputc(ch); |
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| 83 | } |
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| 84 | |||
| 85 | return_from_fs(x); |
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| 86 | } |
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| 87 | |||
| 88 | /* don't try to use bad file descriptor */ |
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| 89 | pid=__get_pid(); |
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| 90 | if (check_fd(pid,fd)) { |
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| 91 | printk(KERN_INFO "k_read: using bad file descriptor"); |
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| 92 | return_from_fs(-EBADF); |
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| 93 | } |
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| 94 | |||
| 95 | /* don't try to read a directory */ |
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| 96 | if (file_ptr(pid,fd)->f_flag_isdir) return_from_fs(-EBADF); |
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| 97 | |||
| 98 | /* don't try to read into not user memory */ |
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| 99 | if (!__verify_write(buf,nbytes)) return_from_fs(-EVERIFY); |
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| 100 | |||
| 101 | /* if in write only mode */ |
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| 102 | if (*fildesfflags_ptr(pid,fd)&O_WRONLY) |
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| 103 | return_from_fs(-EBOH); |
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| 104 | |||
| 105 | /* cancellation point */ |
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| 106 | //fs_test_cancellation(-EINTR); |
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| 107 | |||
| 108 | /* acquire read lock on inode's file */ |
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| 109 | __rwlock_rdlock(&file_ptr(pid,fd)->f_dentry->d_inode->i_lock); |
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| 110 | |||
| 111 | /* O_APPEND flags */ |
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| 112 | if (*fildesfflags_ptr(pid,fd)&O_APPEND) { |
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| 113 | sz=0; |
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| 114 | goto SKIP; |
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| 115 | } |
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| 116 | |||
| 117 | /* WARNING buf is a pointer into user-space! */ |
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| 118 | sz=file_ptr(pid,fd)->f_op->read(file_ptr(pid,fd),buf,nbytes); |
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| 119 | |||
| 120 | /* release the lock */ |
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| 121 | SKIP: |
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| 122 | __rwlock_rdunlock(&file_ptr(pid,fd)->f_dentry->d_inode->i_lock); |
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| 123 | |||
| 124 | return_from_fs(sz); |
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| 125 | } |