ceph: preserve I_COMPLETE across rename

d_move puts the renamed dentry at the end of d_subdirs, screwing with our
cached dentry directory offsets.  We were just clearing I_COMPLETE to avoid
any possibility of trouble.  However, assigning the renamed dentry an
offset at the end of the directory (to match it's new d_subdirs position)
is sufficient to maintain correct behavior and hold onto I_COMPLETE.

This is especially important for workloads like rsync, which renames files
into place.  Before, we would lose I_COMPLETE and do MDS lookups for each
file.  With this patch we only talk to the MDS on create and rename.

Signed-off-by: Sage Weil <sage@newdream.net>
This commit is contained in:
Sage Weil 2011-02-04 21:38:47 -08:00
parent b09734b1f4
commit 09adc80c61

View File

@ -1030,9 +1030,6 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
dout("fill_trace doing d_move %p -> %p\n",
req->r_old_dentry, dn);
/* d_move screws up d_subdirs order */
ceph_i_clear(dir, CEPH_I_COMPLETE);
d_move(req->r_old_dentry, dn);
dout(" src %p '%.*s' dst %p '%.*s'\n",
req->r_old_dentry,
@ -1044,12 +1041,15 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
rehashing bug in vfs_rename_dir */
ceph_invalidate_dentry_lease(dn);
/* take overwritten dentry's readdir offset */
dout("dn %p gets %p offset %lld (old offset %lld)\n",
req->r_old_dentry, dn, ceph_dentry(dn)->offset,
/*
* d_move() puts the renamed dentry at the end of
* d_subdirs. We need to assign it an appropriate
* directory offset so we can behave when holding
* I_COMPLETE.
*/
ceph_set_dentry_offset(req->r_old_dentry);
dout("dn %p gets new offset %lld\n", req->r_old_dentry,
ceph_dentry(req->r_old_dentry)->offset);
ceph_dentry(req->r_old_dentry)->offset =
ceph_dentry(dn)->offset;
dn = req->r_old_dentry; /* use old_dentry */
in = dn->d_inode;