mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-30 08:02:30 +00:00
ceph: fix rdcache_gen usage and invalidate
We used to use rdcache_gen to indicate whether we "might" have cached pages. Now we just look at the mapping to determine that. However, some old behavior remains from that transition. First, rdcache_gen == 0 no longer means we have no pages. That can happen at any time (presumably when we carry FILE_CACHE). We should not reset it to zero, and we should not check that it is zero. That means that the only purpose for rdcache_revoking is to resolve races between new issues of FILE_CACHE and an async invalidate. If they are equal, we should invalidate. On success, we decrement rdcache_revoking, so that it is no longer equal to rdcache_gen. Similarly, if we success in doing a sync invalidate, set revoking = gen - 1. (This is a small optimization to avoid doing unnecessary invalidate work and does not affect correctness.) Signed-off-by: Sage Weil <sage@newdream.net>
This commit is contained in:
parent
feb4cc9bb4
commit
cd045cb42a
3 changed files with 10 additions and 14 deletions
|
@ -1430,8 +1430,8 @@ static int try_nonblocking_invalidate(struct inode *inode)
|
|||
invalidating_gen == ci->i_rdcache_gen) {
|
||||
/* success. */
|
||||
dout("try_nonblocking_invalidate %p success\n", inode);
|
||||
ci->i_rdcache_gen = 0;
|
||||
ci->i_rdcache_revoking = 0;
|
||||
/* save any racing async invalidate some trouble */
|
||||
ci->i_rdcache_revoking = ci->i_rdcache_gen - 1;
|
||||
return 0;
|
||||
}
|
||||
dout("try_nonblocking_invalidate %p failed\n", inode);
|
||||
|
|
|
@ -1394,11 +1394,8 @@ static void ceph_invalidate_work(struct work_struct *work)
|
|||
spin_lock(&inode->i_lock);
|
||||
dout("invalidate_pages %p gen %d revoking %d\n", inode,
|
||||
ci->i_rdcache_gen, ci->i_rdcache_revoking);
|
||||
if (ci->i_rdcache_gen == 0 ||
|
||||
ci->i_rdcache_revoking != ci->i_rdcache_gen) {
|
||||
BUG_ON(ci->i_rdcache_revoking > ci->i_rdcache_gen);
|
||||
if (ci->i_rdcache_revoking != ci->i_rdcache_gen) {
|
||||
/* nevermind! */
|
||||
ci->i_rdcache_revoking = 0;
|
||||
spin_unlock(&inode->i_lock);
|
||||
goto out;
|
||||
}
|
||||
|
@ -1408,15 +1405,16 @@ static void ceph_invalidate_work(struct work_struct *work)
|
|||
ceph_invalidate_nondirty_pages(inode->i_mapping);
|
||||
|
||||
spin_lock(&inode->i_lock);
|
||||
if (orig_gen == ci->i_rdcache_gen) {
|
||||
if (orig_gen == ci->i_rdcache_gen &&
|
||||
orig_gen == ci->i_rdcache_revoking) {
|
||||
dout("invalidate_pages %p gen %d successful\n", inode,
|
||||
ci->i_rdcache_gen);
|
||||
ci->i_rdcache_gen = 0;
|
||||
ci->i_rdcache_revoking = 0;
|
||||
ci->i_rdcache_revoking--;
|
||||
check = 1;
|
||||
} else {
|
||||
dout("invalidate_pages %p gen %d raced, gen now %d\n",
|
||||
inode, orig_gen, ci->i_rdcache_gen);
|
||||
dout("invalidate_pages %p gen %d raced, now %d revoking %d\n",
|
||||
inode, orig_gen, ci->i_rdcache_gen,
|
||||
ci->i_rdcache_revoking);
|
||||
}
|
||||
spin_unlock(&inode->i_lock);
|
||||
|
||||
|
|
|
@ -293,9 +293,7 @@ struct ceph_inode_info {
|
|||
int i_rd_ref, i_rdcache_ref, i_wr_ref;
|
||||
int i_wrbuffer_ref, i_wrbuffer_ref_head;
|
||||
u32 i_shared_gen; /* increment each time we get FILE_SHARED */
|
||||
u32 i_rdcache_gen; /* we increment this each time we get
|
||||
FILE_CACHE. If it's non-zero, we
|
||||
_may_ have cached pages. */
|
||||
u32 i_rdcache_gen; /* incremented each time we get FILE_CACHE. */
|
||||
u32 i_rdcache_revoking; /* RDCACHE gen to async invalidate, if any */
|
||||
|
||||
struct list_head i_unsafe_writes; /* uncommitted sync writes */
|
||||
|
|
Loading…
Reference in a new issue