[XFS] stop using xfs_itobp in xfs_iread
The only caller of xfs_itobp that doesn't have i_blkno setup is now
the initial inode read. It needs access to the whole xfs_imap so using
xfs_inotobp is not an option. Instead opencode the buffer lookup in
xfs_iread and kill all the functionality for the initial map from
xfs_itobp.
(First sent on October 21st)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 083395c..1d5c28b 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -262,15 +262,11 @@
* If a non-zero error is returned, then the contents of bpp and
* dipp are undefined.
*
- * If the inode is new and has not yet been initialized, use xfs_imap()
- * to determine the size and location of the buffer to read from disk.
- * If the inode has already been mapped to its buffer and read in once,
- * then use the mapping information stored in the inode rather than
- * calling xfs_imap(). This allows us to avoid the overhead of looking
- * at the inode btree for small block file systems (see xfs_dilocate()).
- * We can tell whether the inode has been mapped in before by comparing
- * its disk block address to 0. Only uninitialized inodes will have
- * 0 for the disk block address.
+ * The inode is expected to already been mapped to its buffer and read
+ * in once, thus we can use the mapping information stored in the inode
+ * rather than calling xfs_imap(). This allows us to avoid the overhead
+ * of looking at the inode btree for small block file systems
+ * (see xfs_dilocate()).
*/
int
xfs_itobp(
@@ -279,40 +275,19 @@
xfs_inode_t *ip,
xfs_dinode_t **dipp,
xfs_buf_t **bpp,
- xfs_daddr_t bno,
- uint imap_flags,
uint buf_flags)
{
xfs_imap_t imap;
xfs_buf_t *bp;
int error;
- if (ip->i_blkno == (xfs_daddr_t)0) {
- imap.im_blkno = bno;
- error = xfs_imap(mp, tp, ip->i_ino, &imap,
- XFS_IMAP_LOOKUP | imap_flags);
- if (error)
- return error;
+ ASSERT(ip->i_blkno != 0);
- /*
- * Fill in the fields in the inode that will be used to
- * map the inode to its buffer from now on.
- */
- ip->i_blkno = imap.im_blkno;
- ip->i_len = imap.im_len;
- ip->i_boffset = imap.im_boffset;
- } else {
- /*
- * We've already mapped the inode once, so just use the
- * mapping that we saved the first time.
- */
- imap.im_blkno = ip->i_blkno;
- imap.im_len = ip->i_len;
- imap.im_boffset = ip->i_boffset;
- }
- ASSERT(bno == 0 || bno == imap.im_blkno);
+ imap.im_blkno = ip->i_blkno;
+ imap.im_len = ip->i_len;
+ imap.im_boffset = ip->i_boffset;
- error = xfs_imap_to_bp(mp, tp, &imap, &bp, buf_flags, imap_flags);
+ error = xfs_imap_to_bp(mp, tp, &imap, &bp, buf_flags, 0);
if (error)
return error;
@@ -882,6 +857,7 @@
xfs_buf_t *bp;
xfs_dinode_t *dip;
xfs_inode_t *ip;
+ xfs_imap_t imap;
int error;
ip = xfs_inode_alloc(mp, ino);
@@ -889,17 +865,29 @@
return ENOMEM;
/*
- * Get pointer's to the on-disk inode and the buffer containing it.
- * If the inode number refers to a block outside the file system
- * then xfs_itobp() will return NULL. In this case we should
- * return NULL as well. Set i_blkno to 0 so that xfs_itobp() will
- * know that this is a new incore inode.
+ * Get pointers to the on-disk inode and the buffer containing it.
*/
- error = xfs_itobp(mp, tp, ip, &dip, &bp, bno, imap_flags, XFS_BUF_LOCK);
+ imap.im_blkno = bno;
+ error = xfs_imap(mp, tp, ip->i_ino, &imap,
+ XFS_IMAP_LOOKUP | imap_flags);
if (error)
goto out_destroy_inode;
/*
+ * Fill in the fields in the inode that will be used to
+ * map the inode to its buffer from now on.
+ */
+ ip->i_blkno = imap.im_blkno;
+ ip->i_len = imap.im_len;
+ ip->i_boffset = imap.im_boffset;
+ ASSERT(bno == 0 || bno == imap.im_blkno);
+
+ error = xfs_imap_to_bp(mp, tp, &imap, &bp, XFS_BUF_LOCK, imap_flags);
+ if (error)
+ goto out_destroy_inode;
+ dip = (xfs_dinode_t *)xfs_buf_offset(bp, imap.im_boffset);
+
+ /*
* If we got something that isn't an inode it means someone
* (nfs or dmi) has a stale handle.
*/
@@ -1878,7 +1866,7 @@
* Here we put the head pointer into our next pointer,
* and then we fall through to point the head at us.
*/
- error = xfs_itobp(mp, tp, ip, &dip, &ibp, 0, 0, XFS_BUF_LOCK);
+ error = xfs_itobp(mp, tp, ip, &dip, &ibp, XFS_BUF_LOCK);
if (error)
return error;
@@ -1960,7 +1948,7 @@
* of dealing with the buffer when there is no need to
* change it.
*/
- error = xfs_itobp(mp, tp, ip, &dip, &ibp, 0, 0, XFS_BUF_LOCK);
+ error = xfs_itobp(mp, tp, ip, &dip, &ibp, XFS_BUF_LOCK);
if (error) {
cmn_err(CE_WARN,
"xfs_iunlink_remove: xfs_itobp() returned an error %d on %s. Returning error.",
@@ -2022,7 +2010,7 @@
* Now last_ibp points to the buffer previous to us on
* the unlinked list. Pull us from the list.
*/
- error = xfs_itobp(mp, tp, ip, &dip, &ibp, 0, 0, XFS_BUF_LOCK);
+ error = xfs_itobp(mp, tp, ip, &dip, &ibp, XFS_BUF_LOCK);
if (error) {
cmn_err(CE_WARN,
"xfs_iunlink_remove: xfs_itobp() returned an error %d on %s. Returning error.",
@@ -2277,7 +2265,7 @@
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
- error = xfs_itobp(ip->i_mount, tp, ip, &dip, &ibp, 0, 0, XFS_BUF_LOCK);
+ error = xfs_itobp(ip->i_mount, tp, ip, &dip, &ibp, XFS_BUF_LOCK);
if (error)
return error;
@@ -3191,7 +3179,7 @@
/*
* Get the buffer containing the on-disk inode.
*/
- error = xfs_itobp(mp, NULL, ip, &dip, &bp, 0, 0,
+ error = xfs_itobp(mp, NULL, ip, &dip, &bp,
noblock ? XFS_BUF_TRYLOCK : XFS_BUF_LOCK);
if (error || !bp) {
xfs_ifunlock(ip);
