fs: Enable bmap() function to properly return errors
By now, bmap() will either return the physical block number related to
the requested file offset or 0 in case of error or the requested offset
maps into a hole.
This patch makes the needed changes to enable bmap() to proper return
errors, using the return value as an error return, and now, a pointer
must be passed to bmap() to be filled with the mapped physical block.
It will change the behavior of bmap() on return:
- negative value in case of error
- zero on success or map fell into a hole
In case of a hole, the *block will be zero too
Since this is a prep patch, by now, the only error return is -EINVAL if
->bmap doesn't exist.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 5e408ee..01fa5d2 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -795,18 +795,23 @@ int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
{
int err = 0;
unsigned long long ret;
+ sector_t block = 0;
if (journal->j_inode) {
- ret = bmap(journal->j_inode, blocknr);
- if (ret)
- *retp = ret;
- else {
+ block = blocknr;
+ ret = bmap(journal->j_inode, &block);
+
+ if (ret || !block) {
printk(KERN_ALERT "%s: journal block not found "
"at offset %lu on %s\n",
__func__, blocknr, journal->j_devname);
err = -EIO;
__journal_abort_soft(journal, err);
+
+ } else {
+ *retp = block;
}
+
} else {
*retp = blocknr; /* +journal->j_blk_offset */
}
@@ -1244,11 +1249,14 @@ journal_t *jbd2_journal_init_dev(struct block_device *bdev,
journal_t *jbd2_journal_init_inode(struct inode *inode)
{
journal_t *journal;
+ sector_t blocknr;
char *p;
- unsigned long long blocknr;
+ int err = 0;
- blocknr = bmap(inode, 0);
- if (!blocknr) {
+ blocknr = 0;
+ err = bmap(inode, &blocknr);
+
+ if (err || !blocknr) {
pr_err("%s: Cannot locate journal superblock\n",
__func__);
return NULL;
