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authorAndrew Morton <akpm@linux-foundation.org>2007-04-02 02:49:44 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-04-02 13:06:08 -0400
commit7479d2b90b103f84d956a7177b3f99cbd472b345 (patch)
treefb0f9978ba10d39be2fa8004536d15764cf69584
parent1aa9b4b9bc10a0cf6e6109c2997d759a76e840e5 (diff)
[PATCH] revert "retries in ext4_prepare_write() violate ordering requirements"
Revert b46be05004abb419e303e66e143eed9f8a6e9f3f. Same reasoning as for ext3. Cc: Kirill Korotaev <dev@openvz.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ken Chen <kenneth.w.chen@intel.com> Cc: Andrey Savochkin <saw@sw.ru> Cc: <linux-ext4@vger.kernel.org> Cc: Dmitriy Monakhov <dmonakhov@openvz.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/ext4/inode.c85
1 files changed, 10 insertions, 75 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index fbff4b9e122a..810b6d6474bf 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1147,102 +1147,37 @@ static int do_journal_get_write_access(handle_t *handle,
1147 return ext4_journal_get_write_access(handle, bh); 1147 return ext4_journal_get_write_access(handle, bh);
1148} 1148}
1149 1149
1150/*
1151 * The idea of this helper function is following:
1152 * if prepare_write has allocated some blocks, but not all of them, the
1153 * transaction must include the content of the newly allocated blocks.
1154 * This content is expected to be set to zeroes by block_prepare_write().
1155 * 2006/10/14 SAW
1156 */
1157static int ext4_prepare_failure(struct file *file, struct page *page,
1158 unsigned from, unsigned to)
1159{
1160 struct address_space *mapping;
1161 struct buffer_head *bh, *head, *next;
1162 unsigned block_start, block_end;
1163 unsigned blocksize;
1164 int ret;
1165 handle_t *handle = ext4_journal_current_handle();
1166
1167 mapping = page->mapping;
1168 if (ext4_should_writeback_data(mapping->host)) {
1169 /* optimization: no constraints about data */
1170skip:
1171 return ext4_journal_stop(handle);
1172 }
1173
1174 head = page_buffers(page);
1175 blocksize = head->b_size;
1176 for ( bh = head, block_start = 0;
1177 bh != head || !block_start;
1178 block_start = block_end, bh = next)
1179 {
1180 next = bh->b_this_page;
1181 block_end = block_start + blocksize;
1182 if (block_end <= from)
1183 continue;
1184 if (block_start >= to) {
1185 block_start = to;
1186 break;
1187 }
1188 if (!buffer_mapped(bh))
1189 /* prepare_write failed on this bh */
1190 break;
1191 if (ext4_should_journal_data(mapping->host)) {
1192 ret = do_journal_get_write_access(handle, bh);
1193 if (ret) {
1194 ext4_journal_stop(handle);
1195 return ret;
1196 }
1197 }
1198 /*
1199 * block_start here becomes the first block where the current iteration
1200 * of prepare_write failed.
1201 */
1202 }
1203 if (block_start <= from)
1204 goto skip;
1205
1206 /* commit allocated and zeroed buffers */
1207 return mapping->a_ops->commit_write(file, page, from, block_start);
1208}
1209
1210static int ext4_prepare_write(struct file *file, struct page *page, 1150static int ext4_prepare_write(struct file *file, struct page *page,
1211 unsigned from, unsigned to) 1151 unsigned from, unsigned to)
1212{ 1152{
1213 struct inode *inode = page->mapping->host; 1153 struct inode *inode = page->mapping->host;
1214 int ret, ret2; 1154 int ret, needed_blocks = ext4_writepage_trans_blocks(inode);
1215 int needed_blocks = ext4_writepage_trans_blocks(inode);
1216 handle_t *handle; 1155 handle_t *handle;
1217 int retries = 0; 1156 int retries = 0;
1218 1157
1219retry: 1158retry:
1220 handle = ext4_journal_start(inode, needed_blocks); 1159 handle = ext4_journal_start(inode, needed_blocks);
1221 if (IS_ERR(handle)) 1160 if (IS_ERR(handle)) {
1222 return PTR_ERR(handle); 1161 ret = PTR_ERR(handle);
1162 goto out;
1163 }
1223 if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode)) 1164 if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
1224 ret = nobh_prepare_write(page, from, to, ext4_get_block); 1165 ret = nobh_prepare_write(page, from, to, ext4_get_block);
1225 else 1166 else
1226 ret = block_prepare_write(page, from, to, ext4_get_block); 1167 ret = block_prepare_write(page, from, to, ext4_get_block);
1227 if (ret) 1168 if (ret)
1228 goto failure; 1169 goto prepare_write_failed;
1229 1170
1230 if (ext4_should_journal_data(inode)) { 1171 if (ext4_should_journal_data(inode)) {
1231 ret = walk_page_buffers(handle, page_buffers(page), 1172 ret = walk_page_buffers(handle, page_buffers(page),
1232 from, to, NULL, do_journal_get_write_access); 1173 from, to, NULL, do_journal_get_write_access);
1233 if (ret)
1234 /* fatal error, just put the handle and return */
1235 ext4_journal_stop(handle);
1236 } 1174 }
1237 return ret; 1175prepare_write_failed:
1238 1176 if (ret)
1239failure: 1177 ext4_journal_stop(handle);
1240 ret2 = ext4_prepare_failure(file, page, from, to);
1241 if (ret2 < 0)
1242 return ret2;
1243 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) 1178 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1244 goto retry; 1179 goto retry;
1245 /* retry number exceeded, or other error like -EDQUOT */ 1180out:
1246 return ret; 1181 return ret;
1247} 1182}
1248 1183