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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 | /* * linux/fs/minix/file.c * * Copyright (C) 1991, 1992 Linus Torvalds * * minix regular file handling primitives */ #include <linux/sched.h> #include <linux/minix_fs.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/fcntl.h> #include <linux/stat.h> #include <linux/locks.h> #include <linux/mm.h> #include <linux/pagemap.h> #include <asm/segment.h> #include <asm/system.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/minix_fs.h> static long minix_file_write(struct inode *, struct file *, const char *, unsigned long); /* * We have mostly NULL's here: the current defaults are ok for * the minix filesystem. */ static struct file_operations minix_file_operations = { NULL, /* lseek - default */ generic_file_read, /* read */ minix_file_write, /* write */ NULL, /* readdir - bad */ NULL, /* select - default */ NULL, /* ioctl - default */ generic_file_mmap, /* mmap */ NULL, /* no special open is needed */ NULL, /* release */ minix_sync_file /* fsync */ }; struct inode_operations minix_file_inode_operations = { &minix_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 */ minix_bmap, /* bmap */ minix_truncate, /* truncate */ NULL /* permission */ }; static long minix_file_write(struct inode * inode, struct file * filp, const char * buf, unsigned long count) { off_t pos; int written,c; struct buffer_head * bh; char * p; if (!inode) { printk("minix_file_write: inode = NULL\n"); return -EINVAL; } if (!S_ISREG(inode->i_mode)) { printk("minix_file_write: mode = %07o\n",inode->i_mode); return -EINVAL; } if (filp->f_flags & O_APPEND) pos = inode->i_size; else pos = filp->f_pos; written = 0; while (written < count) { bh = minix_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); mark_buffer_uptodate(bh, 1); mark_buffer_dirty(bh, 0); brelse(bh); pos += c; written += c; buf += c; } if (pos > inode->i_size) inode->i_size = pos; inode->i_mtime = inode->i_ctime = CURRENT_TIME; filp->f_pos = pos; inode->i_dirt = 1; return written; } |