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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 | /* * linux/fs/ext2/file.c * * Copyright (C) 1992, 1993, 1994, 1995 * Remy Card (card@masi.ibp.fr) * Laboratoire MASI - Institut Blaise Pascal * Universite Pierre et Marie Curie (Paris VI) * * from * * linux/fs/minix/file.c * * Copyright (C) 1991, 1992 Linus Torvalds * * ext2 fs regular file handling primitives */ #include <asm/segment.h> #include <asm/system.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/ext2_fs.h> #include <linux/fcntl.h> #include <linux/sched.h> #include <linux/stat.h> #include <linux/locks.h> #include <linux/mm.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/ext2_fs.h> static int ext2_file_write (struct inode *, struct file *, const char *, int); static void ext2_release_file (struct inode *, struct file *); /* * We have mostly NULL's here: the current defaults are ok for * the ext2 filesystem. */ static struct file_operations ext2_file_operations = { NULL, /* lseek - default */ generic_file_read, /* read */ ext2_file_write, /* write */ NULL, /* readdir - bad */ NULL, /* select - default */ ext2_ioctl, /* ioctl */ generic_file_mmap, /* mmap */ NULL, /* no special open is needed */ ext2_release_file, /* release */ ext2_sync_file, /* fsync */ NULL, /* fasync */ NULL, /* check_media_change */ NULL /* revalidate */ }; struct inode_operations ext2_file_inode_operations = { &ext2_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 */ ext2_bmap, /* bmap */ ext2_truncate, /* truncate */ ext2_permission, /* permission */ NULL /* smap */ }; static int ext2_file_write (struct inode * inode, struct file * filp, const char * buf, int count) { const loff_t two_gb = 2147483647; loff_t pos; off_t pos2; long block; int offset; int written, c; struct buffer_head * bh, *bufferlist[NBUF]; struct super_block * sb; int err; int i,buffercount,write_error; write_error = buffercount = 0; if (!inode) { printk("ext2_file_write: inode = NULL\n"); return -EINVAL; } sb = inode->i_sb; if (sb->s_flags & MS_RDONLY) /* * This fs has been automatically remounted ro because of errors */ return -ENOSPC; if (!S_ISREG(inode->i_mode)) { ext2_warning (sb, "ext2_file_write", "mode = %07o", inode->i_mode); return -EINVAL; } if (filp->f_flags & O_APPEND) pos = inode->i_size; else pos = filp->f_pos; pos2 = (off_t) pos; /* * If a file has been opened in synchronous mode, we have to ensure * that meta-data will also be written synchronously. Thus, we * set the i_osync field. This field is tested by the allocation * routines. */ if (filp->f_flags & O_SYNC) inode->u.ext2_i.i_osync++; block = pos2 >> EXT2_BLOCK_SIZE_BITS(sb); offset = pos2 & (sb->s_blocksize - 1); c = sb->s_blocksize - offset; written = 0; while (count > 0) { if (pos > two_gb) { if (!written) written = -EFBIG; break; } bh = ext2_getblk (inode, block, 1, &err); if (!bh) { if (!written) written = err; break; } count -= c; if (count < 0) c += count; if (c != sb->s_blocksize && !buffer_uptodate(bh)) { ll_rw_block (READ, 1, &bh); wait_on_buffer (bh); if (!buffer_uptodate(bh)) { brelse (bh); if (!written) written = -EIO; break; } } memcpy_fromfs (bh->b_data + offset, buf, c); update_vm_cache(inode, pos, bh->b_data + offset, c); pos2 += c; pos += c; written += c; buf += c; mark_buffer_uptodate(bh, 1); mark_buffer_dirty(bh, 0); if (filp->f_flags & O_SYNC) bufferlist[buffercount++] = bh; else brelse(bh); if (buffercount == NBUF){ ll_rw_block(WRITE, buffercount, bufferlist); for(i=0; i<buffercount; i++){ wait_on_buffer(bufferlist[i]); if (!buffer_uptodate(bufferlist[i])) write_error=1; brelse(bufferlist[i]); } buffercount=0; } if(write_error) break; block++; offset = 0; c = sb->s_blocksize; } if ( buffercount ){ ll_rw_block(WRITE, buffercount, bufferlist); for(i=0; i<buffercount; i++){ wait_on_buffer(bufferlist[i]); if (!buffer_uptodate(bufferlist[i])) write_error=1; brelse(bufferlist[i]); } } if (pos > inode->i_size) inode->i_size = pos; if (filp->f_flags & O_SYNC) inode->u.ext2_i.i_osync--; inode->i_ctime = inode->i_mtime = CURRENT_TIME; filp->f_pos = pos; inode->i_dirt = 1; return written; } /* * Called when a inode is released. Note that this is different * from ext2_open: open gets called at every open, but release * gets called only when /all/ the files are closed. */ static void ext2_release_file (struct inode * inode, struct file * filp) { if (filp->f_mode & 2) ext2_discard_prealloc (inode); } |