1 files changed, 76 insertions, 29 deletions

diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 76e22c9c9c6c..fcfb10f77120 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -330,7 +330,7 @@ static int ext3_block_to_path(struct inode *inode,
                 ext3_warning (inode->i_sb, "ext3_block_to_path", "block > big");
         }
         if (boundary)
-                *boundary = (i_block & (ptrs - 1)) == (final - 1);
+                *boundary = final - 1 - (i_block & (ptrs - 1));
         return n;
 }
 
@@ -669,11 +669,15 @@ err_out:
  * akpm: `handle' can be NULL if create == 0.
  *
  * The BKL may not be held on entry here.  Be sure to take it early.
+ * return > 0, # of blocks mapped or allocated.
+ * return = 0, if plain lookup failed.
+ * return < 0, error case.
  */
 
 int
-ext3_get_block_handle(handle_t *handle, struct inode *inode, sector_t iblock,
-                struct buffer_head *bh_result, int create, int extend_disksize)
+ext3_get_blocks_handle(handle_t *handle, struct inode *inode, sector_t iblock,
+                unsigned long maxblocks, struct buffer_head *bh_result,
+                int create, int extend_disksize)
 {
         int err = -EIO;
         int offsets[4];
@@ -681,11 +685,15 @@ ext3_get_block_handle(handle_t *handle, struct inode *inode, sector_t iblock,
         Indirect *partial;
         unsigned long goal;
         int left;
-        int boundary = 0;
-        const int depth = ext3_block_to_path(inode, iblock, offsets, &boundary);
+        int blocks_to_boundary = 0;
+        int depth;
         struct ext3_inode_info *ei = EXT3_I(inode);
+        int count = 0;
+        unsigned long first_block = 0;
+
 
         J_ASSERT(handle != NULL || create == 0);
+        depth = ext3_block_to_path(inode, iblock, offsets, &blocks_to_boundary);
 
         if (depth == 0)
                 goto out;
@@ -694,8 +702,31 @@ ext3_get_block_handle(handle_t *handle, struct inode *inode, sector_t iblock,
 
         /* Simplest case - block found, no allocation needed */
         if (!partial) {
+                first_block = chain[depth - 1].key;
                 clear_buffer_new(bh_result);
-                goto got_it;
+                count++;
+                /*map more blocks*/
+                while (count < maxblocks && count <= blocks_to_boundary) {
+                        if (!verify_chain(chain, partial)) {
+                                /*
+                                 * Indirect block might be removed by
+                                 * truncate while we were reading it.
+                                 * Handling of that case: forget what we've
+                                 * got now. Flag the err as EAGAIN, so it
+                                 * will reread.
+                                 */
+                                err = -EAGAIN;
+                                count = 0;
+                                break;
+                        }
+                        if (le32_to_cpu(*(chain[depth-1].p+count) ==
+                                        (first_block + count)))
+                                count++;
+                        else
+                                break;
+                }
+                if (err != -EAGAIN)
+                        goto got_it;
         }
 
         /* Next simple case - plain lookup or failed read of indirect block */
@@ -723,6 +754,7 @@ ext3_get_block_handle(handle_t *handle, struct inode *inode, sector_t iblock,
                 }
                 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
                 if (!partial) {
+                        count++;
                         mutex_unlock(&ei->truncate_mutex);
                         if (err)
                                 goto cleanup;
@@ -772,8 +804,9 @@ ext3_get_block_handle(handle_t *handle, struct inode *inode, sector_t iblock,
         set_buffer_new(bh_result);
 got_it:
         map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
-        if (boundary)
+        if (blocks_to_boundary == 0)
                 set_buffer_boundary(bh_result);
+        err = count;
         /* Clean up and exit */
         partial = chain + depth - 1;    /* the whole chain */
 cleanup:
@@ -787,21 +820,6 @@ out:
         return err;
 }
 
-static int ext3_get_block(struct inode *inode, sector_t iblock,
-                        struct buffer_head *bh_result, int create)
-{
-        handle_t *handle = NULL;
-        int ret;
-
-        if (create) {
-                handle = ext3_journal_current_handle();
-                J_ASSERT(handle != 0);
-        }
-        ret = ext3_get_block_handle(handle, inode, iblock,
-                                bh_result, create, 1);
-        return ret;
-}
-
 #define DIO_CREDITS (EXT3_RESERVE_TRANS_BLOCKS + 32)
 
 static int
@@ -812,9 +830,12 @@ ext3_direct_io_get_blocks(struct inode *inode, sector_t iblock,
         handle_t *handle = journal_current_handle();
         int ret = 0;
 
-        if (!handle)
+        if (!create)
                 goto get_block;         /* A read */
 
+        if (max_blocks == 1)
+                goto get_block;         /* A single block get */
+
         if (handle->h_transaction->t_state == T_LOCKED) {
                 /*
                  * Huge direct-io writes can hold off commits for long
@@ -841,13 +862,31 @@ ext3_direct_io_get_blocks(struct inode *inode, sector_t iblock,
         }
 
 get_block:
-        if (ret == 0)
-                ret = ext3_get_block_handle(handle, inode, iblock,
-                                        bh_result, create, 0);
-        bh_result->b_size = (1 << inode->i_blkbits);
+        if (ret == 0) {
+                ret = ext3_get_blocks_handle(handle, inode, iblock,
+                                        max_blocks, bh_result, create, 0);
+                if (ret > 0) {
+                        bh_result->b_size = (ret << inode->i_blkbits);
+                        ret = 0;
+                }
+        }
         return ret;
 }
 
+static int ext3_get_blocks(struct inode *inode, sector_t iblock,
+                unsigned long maxblocks, struct buffer_head *bh_result,
+                int create)
+{
+        return ext3_direct_io_get_blocks(inode, iblock, maxblocks,
+                                        bh_result, create);
+}
+
+static int ext3_get_block(struct inode *inode, sector_t iblock,
+                        struct buffer_head *bh_result, int create)
+{
+        return ext3_get_blocks(inode, iblock, 1, bh_result, create);
+}
+
 /*
  * `handle' can be NULL if create is zero
  */
@@ -862,8 +901,16 @@ struct buffer_head *ext3_getblk(handle_t *handle, struct inode * inode,
         dummy.b_state = 0;
         dummy.b_blocknr = -1000;
         buffer_trace_init(&dummy.b_history);
-        *errp = ext3_get_block_handle(handle, inode, block, &dummy, create, 1);
-        if (!*errp && buffer_mapped(&dummy)) {
+        err = ext3_get_blocks_handle(handle, inode, block, 1,
+                                        &dummy, create, 1);
+        if (err == 1) {
+                err = 0;
+        } else if (err >= 0) {
+                WARN_ON(1);
+                err = -EIO;
+        }
+        *errp = err;
+        if (!err && buffer_mapped(&dummy)) {
                 struct buffer_head *bh;
                 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
                 if (!bh) {