ocfs2: Teach ocfs2_get_block() about holes
ocfs2_get_block() didn't understand sparse files, fix that. Also remove some
code that isn't really useful anymore. We can fix up
ocfs2_direct_IO_get_blocks() at the same time.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 8368036..acf8f00 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -137,6 +137,7 @@
{
int err = 0;
u64 p_blkno, past_eof;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
(unsigned long long)iblock, bh_result, create);
@@ -151,15 +152,6 @@
goto bail;
}
- /* this can happen if another node truncs after our extend! */
- spin_lock(&OCFS2_I(inode)->ip_lock);
- if (iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
- OCFS2_I(inode)->ip_clusters))
- err = -EIO;
- spin_unlock(&OCFS2_I(inode)->ip_lock);
- if (err)
- goto bail;
-
err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, NULL);
if (err) {
mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
@@ -168,23 +160,39 @@
goto bail;
}
- map_bh(bh_result, inode->i_sb, p_blkno);
+ /*
+ * ocfs2 never allocates in this function - the only time we
+ * need to use BH_New is when we're extending i_size on a file
+ * system which doesn't support holes, in which case BH_New
+ * allows block_prepare_write() to zero.
+ */
+ mlog_bug_on_msg(create && p_blkno == 0 && ocfs2_sparse_alloc(osb),
+ "ino %lu, iblock %llu\n", inode->i_ino,
+ (unsigned long long)iblock);
- if (bh_result->b_blocknr == 0) {
- err = -EIO;
- mlog(ML_ERROR, "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
- (unsigned long long)iblock,
- (unsigned long long)p_blkno,
- (unsigned long long)OCFS2_I(inode)->ip_blkno);
+ if (p_blkno)
+ map_bh(bh_result, inode->i_sb, p_blkno);
+
+ if (!ocfs2_sparse_alloc(osb)) {
+ if (p_blkno == 0) {
+ err = -EIO;
+ mlog(ML_ERROR,
+ "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
+ (unsigned long long)iblock,
+ (unsigned long long)p_blkno,
+ (unsigned long long)OCFS2_I(inode)->ip_blkno);
+ mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
+ dump_stack();
+ }
+
+ past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
+ mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino,
+ (unsigned long long)past_eof);
+
+ if (create && (iblock >= past_eof))
+ set_buffer_new(bh_result);
}
- past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
- mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino,
- (unsigned long long)past_eof);
-
- if (create && (iblock >= past_eof))
- set_buffer_new(bh_result);
-
bail:
if (err < 0)
err = -EIO;
@@ -436,28 +444,15 @@
* nicely aligned and of the right size, so there's no need
* for us to check any of that. */
- spin_lock(&OCFS2_I(inode)->ip_lock);
- inode_blocks = ocfs2_clusters_to_blocks(inode->i_sb,
- OCFS2_I(inode)->ip_clusters);
-
- /*
- * For a read which begins past the end of file, we return a hole.
- */
- if (!create && (iblock >= inode_blocks)) {
- spin_unlock(&OCFS2_I(inode)->ip_lock);
- ret = 0;
- goto bail;
- }
+ inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
/*
* Any write past EOF is not allowed because we'd be extending.
*/
if (create && (iblock + max_blocks) > inode_blocks) {
- spin_unlock(&OCFS2_I(inode)->ip_lock);
ret = -EIO;
goto bail;
}
- spin_unlock(&OCFS2_I(inode)->ip_lock);
/* This figures out the size of the next contiguous block, and
* our logical offset */
@@ -470,7 +465,35 @@
goto bail;
}
- map_bh(bh_result, inode->i_sb, p_blkno);
+ if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)) && !p_blkno) {
+ ocfs2_error(inode->i_sb,
+ "Inode %llu has a hole at block %llu\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno,
+ (unsigned long long)iblock);
+ ret = -EROFS;
+ goto bail;
+ }
+
+ /*
+ * get_more_blocks() expects us to describe a hole by clearing
+ * the mapped bit on bh_result().
+ */
+ if (p_blkno)
+ map_bh(bh_result, inode->i_sb, p_blkno);
+ else {
+ /*
+ * ocfs2_prepare_inode_for_write() should have caught
+ * the case where we'd be filling a hole and triggered
+ * a buffered write instead.
+ */
+ if (create) {
+ ret = -EIO;
+ mlog_errno(ret);
+ goto bail;
+ }
+
+ clear_buffer_mapped(bh_result);
+ }
/* make sure we don't map more than max_blocks blocks here as
that's all the kernel will handle at this point. */