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-rw-r--r--fs/xfs/linux-2.6/xfs_aops.c367
1 files changed, 183 insertions, 184 deletions
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index 74d8be87f983..58fc7ade90b5 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -43,7 +43,32 @@
43#include <linux/pagevec.h> 43#include <linux/pagevec.h>
44#include <linux/writeback.h> 44#include <linux/writeback.h>
45 45
46STATIC void xfs_count_page_state(struct page *, int *, int *, int *); 46
47STATIC void
48xfs_count_page_state(
49 struct page *page,
50 int *delalloc,
51 int *unmapped,
52 int *unwritten)
53{
54 struct buffer_head *bh, *head;
55
56 *delalloc = *unmapped = *unwritten = 0;
57
58 bh = head = page_buffers(page);
59 do {
60 if (buffer_uptodate(bh) && !buffer_mapped(bh))
61 (*unmapped) = 1;
62 else if (buffer_unwritten(bh) && !buffer_delay(bh))
63 clear_buffer_unwritten(bh);
64 else if (buffer_unwritten(bh))
65 (*unwritten) = 1;
66 else if (buffer_delay(bh))
67 (*delalloc) = 1;
68 } while ((bh = bh->b_this_page) != head);
69}
70
71
47 72
48#if defined(XFS_RW_TRACE) 73#if defined(XFS_RW_TRACE)
49void 74void
@@ -1040,6 +1065,154 @@ error:
1040 return err; 1065 return err;
1041} 1066}
1042 1067
1068/*
1069 * writepage: Called from one of two places:
1070 *
1071 * 1. we are flushing a delalloc buffer head.
1072 *
1073 * 2. we are writing out a dirty page. Typically the page dirty
1074 * state is cleared before we get here. In this case is it
1075 * conceivable we have no buffer heads.
1076 *
1077 * For delalloc space on the page we need to allocate space and
1078 * flush it. For unmapped buffer heads on the page we should
1079 * allocate space if the page is uptodate. For any other dirty
1080 * buffer heads on the page we should flush them.
1081 *
1082 * If we detect that a transaction would be required to flush
1083 * the page, we have to check the process flags first, if we
1084 * are already in a transaction or disk I/O during allocations
1085 * is off, we need to fail the writepage and redirty the page.
1086 */
1087
1088STATIC int
1089linvfs_writepage(
1090 struct page *page,
1091 struct writeback_control *wbc)
1092{
1093 int error;
1094 int need_trans;
1095 int delalloc, unmapped, unwritten;
1096 struct inode *inode = page->mapping->host;
1097
1098 xfs_page_trace(XFS_WRITEPAGE_ENTER, inode, page, 0);
1099
1100 /*
1101 * We need a transaction if:
1102 * 1. There are delalloc buffers on the page
1103 * 2. The page is uptodate and we have unmapped buffers
1104 * 3. The page is uptodate and we have no buffers
1105 * 4. There are unwritten buffers on the page
1106 */
1107
1108 if (!page_has_buffers(page)) {
1109 unmapped = 1;
1110 need_trans = 1;
1111 } else {
1112 xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
1113 if (!PageUptodate(page))
1114 unmapped = 0;
1115 need_trans = delalloc + unmapped + unwritten;
1116 }
1117
1118 /*
1119 * If we need a transaction and the process flags say
1120 * we are already in a transaction, or no IO is allowed
1121 * then mark the page dirty again and leave the page
1122 * as is.
1123 */
1124 if (PFLAGS_TEST_FSTRANS() && need_trans)
1125 goto out_fail;
1126
1127 /*
1128 * Delay hooking up buffer heads until we have
1129 * made our go/no-go decision.
1130 */
1131 if (!page_has_buffers(page))
1132 create_empty_buffers(page, 1 << inode->i_blkbits, 0);
1133
1134 /*
1135 * Convert delayed allocate, unwritten or unmapped space
1136 * to real space and flush out to disk.
1137 */
1138 error = xfs_page_state_convert(inode, page, wbc, 1, unmapped);
1139 if (error == -EAGAIN)
1140 goto out_fail;
1141 if (unlikely(error < 0))
1142 goto out_unlock;
1143
1144 return 0;
1145
1146out_fail:
1147 redirty_page_for_writepage(wbc, page);
1148 unlock_page(page);
1149 return 0;
1150out_unlock:
1151 unlock_page(page);
1152 return error;
1153}
1154
1155/*
1156 * Called to move a page into cleanable state - and from there
1157 * to be released. Possibly the page is already clean. We always
1158 * have buffer heads in this call.
1159 *
1160 * Returns 0 if the page is ok to release, 1 otherwise.
1161 *
1162 * Possible scenarios are:
1163 *
1164 * 1. We are being called to release a page which has been written
1165 * to via regular I/O. buffer heads will be dirty and possibly
1166 * delalloc. If no delalloc buffer heads in this case then we
1167 * can just return zero.
1168 *
1169 * 2. We are called to release a page which has been written via
1170 * mmap, all we need to do is ensure there is no delalloc
1171 * state in the buffer heads, if not we can let the caller
1172 * free them and we should come back later via writepage.
1173 */
1174STATIC int
1175linvfs_release_page(
1176 struct page *page,
1177 gfp_t gfp_mask)
1178{
1179 struct inode *inode = page->mapping->host;
1180 int dirty, delalloc, unmapped, unwritten;
1181 struct writeback_control wbc = {
1182 .sync_mode = WB_SYNC_ALL,
1183 .nr_to_write = 1,
1184 };
1185
1186 xfs_page_trace(XFS_RELEASEPAGE_ENTER, inode, page, gfp_mask);
1187
1188 xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
1189 if (!delalloc && !unwritten)
1190 goto free_buffers;
1191
1192 if (!(gfp_mask & __GFP_FS))
1193 return 0;
1194
1195 /* If we are already inside a transaction or the thread cannot
1196 * do I/O, we cannot release this page.
1197 */
1198 if (PFLAGS_TEST_FSTRANS())
1199 return 0;
1200
1201 /*
1202 * Convert delalloc space to real space, do not flush the
1203 * data out to disk, that will be done by the caller.
1204 * Never need to allocate space here - we will always
1205 * come back to writepage in that case.
1206 */
1207 dirty = xfs_page_state_convert(inode, page, &wbc, 0, 0);
1208 if (dirty == 0 && !unwritten)
1209 goto free_buffers;
1210 return 0;
1211
1212free_buffers:
1213 return try_to_free_buffers(page);
1214}
1215
1043STATIC int 1216STATIC int
1044__linvfs_get_block( 1217__linvfs_get_block(
1045 struct inode *inode, 1218 struct inode *inode,
@@ -1223,6 +1396,15 @@ linvfs_direct_IO(
1223 return ret; 1396 return ret;
1224} 1397}
1225 1398
1399STATIC int
1400linvfs_prepare_write(
1401 struct file *file,
1402 struct page *page,
1403 unsigned int from,
1404 unsigned int to)
1405{
1406 return block_prepare_write(page, from, to, linvfs_get_block);
1407}
1226 1408
1227STATIC sector_t 1409STATIC sector_t
1228linvfs_bmap( 1410linvfs_bmap(
@@ -1259,118 +1441,6 @@ linvfs_readpages(
1259 return mpage_readpages(mapping, pages, nr_pages, linvfs_get_block); 1441 return mpage_readpages(mapping, pages, nr_pages, linvfs_get_block);
1260} 1442}
1261 1443
1262STATIC void
1263xfs_count_page_state(
1264 struct page *page,
1265 int *delalloc,
1266 int *unmapped,
1267 int *unwritten)
1268{
1269 struct buffer_head *bh, *head;
1270
1271 *delalloc = *unmapped = *unwritten = 0;
1272
1273 bh = head = page_buffers(page);
1274 do {
1275 if (buffer_uptodate(bh) && !buffer_mapped(bh))
1276 (*unmapped) = 1;
1277 else if (buffer_unwritten(bh) && !buffer_delay(bh))
1278 clear_buffer_unwritten(bh);
1279 else if (buffer_unwritten(bh))
1280 (*unwritten) = 1;
1281 else if (buffer_delay(bh))
1282 (*delalloc) = 1;
1283 } while ((bh = bh->b_this_page) != head);
1284}
1285
1286
1287/*
1288 * writepage: Called from one of two places:
1289 *
1290 * 1. we are flushing a delalloc buffer head.
1291 *
1292 * 2. we are writing out a dirty page. Typically the page dirty
1293 * state is cleared before we get here. In this case is it
1294 * conceivable we have no buffer heads.
1295 *
1296 * For delalloc space on the page we need to allocate space and
1297 * flush it. For unmapped buffer heads on the page we should
1298 * allocate space if the page is uptodate. For any other dirty
1299 * buffer heads on the page we should flush them.
1300 *
1301 * If we detect that a transaction would be required to flush
1302 * the page, we have to check the process flags first, if we
1303 * are already in a transaction or disk I/O during allocations
1304 * is off, we need to fail the writepage and redirty the page.
1305 */
1306
1307STATIC int
1308linvfs_writepage(
1309 struct page *page,
1310 struct writeback_control *wbc)
1311{
1312 int error;
1313 int need_trans;
1314 int delalloc, unmapped, unwritten;
1315 struct inode *inode = page->mapping->host;
1316
1317 xfs_page_trace(XFS_WRITEPAGE_ENTER, inode, page, 0);
1318
1319 /*
1320 * We need a transaction if:
1321 * 1. There are delalloc buffers on the page
1322 * 2. The page is uptodate and we have unmapped buffers
1323 * 3. The page is uptodate and we have no buffers
1324 * 4. There are unwritten buffers on the page
1325 */
1326
1327 if (!page_has_buffers(page)) {
1328 unmapped = 1;
1329 need_trans = 1;
1330 } else {
1331 xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
1332 if (!PageUptodate(page))
1333 unmapped = 0;
1334 need_trans = delalloc + unmapped + unwritten;
1335 }
1336
1337 /*
1338 * If we need a transaction and the process flags say
1339 * we are already in a transaction, or no IO is allowed
1340 * then mark the page dirty again and leave the page
1341 * as is.
1342 */
1343 if (PFLAGS_TEST_FSTRANS() && need_trans)
1344 goto out_fail;
1345
1346 /*
1347 * Delay hooking up buffer heads until we have
1348 * made our go/no-go decision.
1349 */
1350 if (!page_has_buffers(page))
1351 create_empty_buffers(page, 1 << inode->i_blkbits, 0);
1352
1353 /*
1354 * Convert delayed allocate, unwritten or unmapped space
1355 * to real space and flush out to disk.
1356 */
1357 error = xfs_page_state_convert(inode, page, wbc, 1, unmapped);
1358 if (error == -EAGAIN)
1359 goto out_fail;
1360 if (unlikely(error < 0))
1361 goto out_unlock;
1362
1363 return 0;
1364
1365out_fail:
1366 redirty_page_for_writepage(wbc, page);
1367 unlock_page(page);
1368 return 0;
1369out_unlock:
1370 unlock_page(page);
1371 return error;
1372}
1373
1374STATIC int 1444STATIC int
1375linvfs_invalidate_page( 1445linvfs_invalidate_page(
1376 struct page *page, 1446 struct page *page,
@@ -1381,77 +1451,6 @@ linvfs_invalidate_page(
1381 return block_invalidatepage(page, offset); 1451 return block_invalidatepage(page, offset);
1382} 1452}
1383 1453
1384/*
1385 * Called to move a page into cleanable state - and from there
1386 * to be released. Possibly the page is already clean. We always
1387 * have buffer heads in this call.
1388 *
1389 * Returns 0 if the page is ok to release, 1 otherwise.
1390 *
1391 * Possible scenarios are:
1392 *
1393 * 1. We are being called to release a page which has been written
1394 * to via regular I/O. buffer heads will be dirty and possibly
1395 * delalloc. If no delalloc buffer heads in this case then we
1396 * can just return zero.
1397 *
1398 * 2. We are called to release a page which has been written via
1399 * mmap, all we need to do is ensure there is no delalloc
1400 * state in the buffer heads, if not we can let the caller
1401 * free them and we should come back later via writepage.
1402 */
1403STATIC int
1404linvfs_release_page(
1405 struct page *page,
1406 gfp_t gfp_mask)
1407{
1408 struct inode *inode = page->mapping->host;
1409 int dirty, delalloc, unmapped, unwritten;
1410 struct writeback_control wbc = {
1411 .sync_mode = WB_SYNC_ALL,
1412 .nr_to_write = 1,
1413 };
1414
1415 xfs_page_trace(XFS_RELEASEPAGE_ENTER, inode, page, gfp_mask);
1416
1417 xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
1418 if (!delalloc && !unwritten)
1419 goto free_buffers;
1420
1421 if (!(gfp_mask & __GFP_FS))
1422 return 0;
1423
1424 /* If we are already inside a transaction or the thread cannot
1425 * do I/O, we cannot release this page.
1426 */
1427 if (PFLAGS_TEST_FSTRANS())
1428 return 0;
1429
1430 /*
1431 * Convert delalloc space to real space, do not flush the
1432 * data out to disk, that will be done by the caller.
1433 * Never need to allocate space here - we will always
1434 * come back to writepage in that case.
1435 */
1436 dirty = xfs_page_state_convert(inode, page, &wbc, 0, 0);
1437 if (dirty == 0 && !unwritten)
1438 goto free_buffers;
1439 return 0;
1440
1441free_buffers:
1442 return try_to_free_buffers(page);
1443}
1444
1445STATIC int
1446linvfs_prepare_write(
1447 struct file *file,
1448 struct page *page,
1449 unsigned int from,
1450 unsigned int to)
1451{
1452 return block_prepare_write(page, from, to, linvfs_get_block);
1453}
1454
1455struct address_space_operations linvfs_aops = { 1454struct address_space_operations linvfs_aops = {
1456 .readpage = linvfs_readpage, 1455 .readpage = linvfs_readpage,
1457 .readpages = linvfs_readpages, 1456 .readpages = linvfs_readpages,