ceph: do not use i_wrbuffer_ref as refcount for Fb cap

We increments i_wrbuffer_ref when taking the Fb cap. This breaks
the dirty page accounting and causes looping in
__ceph_do_pending_vmtruncate, and ceph client hangs.

This bug can be reproduced occasionally by running blogbench.

Add a new field i_wb_ref to inode and dedicate it to Fb reference
counting.

Signed-off-by: Henry C Chang <henry.cy.chang@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
This commit is contained in:
Henry C Chang 2011-05-11 10:29:54 +00:00 committed by Sage Weil
parent a26a185d27
commit d3d0720d4a
3 changed files with 10 additions and 9 deletions

View file

@ -819,7 +819,7 @@ int __ceph_caps_used(struct ceph_inode_info *ci)
used |= CEPH_CAP_FILE_CACHE;
if (ci->i_wr_ref)
used |= CEPH_CAP_FILE_WR;
if (ci->i_wrbuffer_ref)
if (ci->i_wb_ref || ci->i_wrbuffer_ref)
used |= CEPH_CAP_FILE_BUFFER;
return used;
}
@ -1990,11 +1990,11 @@ static void __take_cap_refs(struct ceph_inode_info *ci, int got)
if (got & CEPH_CAP_FILE_WR)
ci->i_wr_ref++;
if (got & CEPH_CAP_FILE_BUFFER) {
if (ci->i_wrbuffer_ref == 0)
if (ci->i_wb_ref == 0)
ihold(&ci->vfs_inode);
ci->i_wrbuffer_ref++;
dout("__take_cap_refs %p wrbuffer %d -> %d (?)\n",
&ci->vfs_inode, ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref);
ci->i_wb_ref++;
dout("__take_cap_refs %p wb %d -> %d (?)\n",
&ci->vfs_inode, ci->i_wb_ref-1, ci->i_wb_ref);
}
}
@ -2169,12 +2169,12 @@ void ceph_put_cap_refs(struct ceph_inode_info *ci, int had)
if (--ci->i_rdcache_ref == 0)
last++;
if (had & CEPH_CAP_FILE_BUFFER) {
if (--ci->i_wrbuffer_ref == 0) {
if (--ci->i_wb_ref == 0) {
last++;
put++;
}
dout("put_cap_refs %p wrbuffer %d -> %d (?)\n",
inode, ci->i_wrbuffer_ref+1, ci->i_wrbuffer_ref);
dout("put_cap_refs %p wb %d -> %d (?)\n",
inode, ci->i_wb_ref+1, ci->i_wb_ref);
}
if (had & CEPH_CAP_FILE_WR)
if (--ci->i_wr_ref == 0) {

View file

@ -355,6 +355,7 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
ci->i_rd_ref = 0;
ci->i_rdcache_ref = 0;
ci->i_wr_ref = 0;
ci->i_wb_ref = 0;
ci->i_wrbuffer_ref = 0;
ci->i_wrbuffer_ref_head = 0;
ci->i_shared_gen = 0;

View file

@ -293,7 +293,7 @@ struct ceph_inode_info {
/* held references to caps */
int i_pin_ref;
int i_rd_ref, i_rdcache_ref, i_wr_ref;
int i_rd_ref, i_rdcache_ref, i_wr_ref, i_wb_ref;
int i_wrbuffer_ref, i_wrbuffer_ref_head;
u32 i_shared_gen; /* increment each time we get FILE_SHARED */
u32 i_rdcache_gen; /* incremented each time we get FILE_CACHE. */