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Diffstat (limited to 'fs/nfs/inode.c')
-rw-r--r--fs/nfs/inode.c51
1 files changed, 43 insertions, 8 deletions
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index ea00b34ff071..28a0a3cbd3b7 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -977,11 +977,11 @@ static int nfs_invalidate_mapping(struct inode *inode, struct address_space *map
if (ret < 0)
return ret;
}
- spin_lock(&inode->i_lock);
- nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
- if (S_ISDIR(inode->i_mode))
+ if (S_ISDIR(inode->i_mode)) {
+ spin_lock(&inode->i_lock);
memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
- spin_unlock(&inode->i_lock);
+ spin_unlock(&inode->i_lock);
+ }
nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
nfs_fscache_wait_on_invalidate(inode);
@@ -1008,6 +1008,7 @@ static bool nfs_mapping_need_revalidate_inode(struct inode *inode)
int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
{
struct nfs_inode *nfsi = NFS_I(inode);
+ unsigned long *bitlock = &nfsi->flags;
int ret = 0;
/* swapfiles are not supposed to be shared. */
@@ -1019,12 +1020,46 @@ int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
if (ret < 0)
goto out;
}
- if (nfsi->cache_validity & NFS_INO_INVALID_DATA) {
- trace_nfs_invalidate_mapping_enter(inode);
- ret = nfs_invalidate_mapping(inode, mapping);
- trace_nfs_invalidate_mapping_exit(inode, ret);
+
+ /*
+ * We must clear NFS_INO_INVALID_DATA first to ensure that
+ * invalidations that come in while we're shooting down the mappings
+ * are respected. But, that leaves a race window where one revalidator
+ * can clear the flag, and then another checks it before the mapping
+ * gets invalidated. Fix that by serializing access to this part of
+ * the function.
+ *
+ * At the same time, we need to allow other tasks to see whether we
+ * might be in the middle of invalidating the pages, so we only set
+ * the bit lock here if it looks like we're going to be doing that.
+ */
+ for (;;) {
+ ret = wait_on_bit(bitlock, NFS_INO_INVALIDATING,
+ nfs_wait_bit_killable, TASK_KILLABLE);
+ if (ret)
+ goto out;
+ spin_lock(&inode->i_lock);
+ if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
+ spin_unlock(&inode->i_lock);
+ continue;
+ }
+ if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
+ break;
+ spin_unlock(&inode->i_lock);
+ goto out;
}
+ set_bit(NFS_INO_INVALIDATING, bitlock);
+ smp_wmb();
+ nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
+ spin_unlock(&inode->i_lock);
+ trace_nfs_invalidate_mapping_enter(inode);
+ ret = nfs_invalidate_mapping(inode, mapping);
+ trace_nfs_invalidate_mapping_exit(inode, ret);
+
+ clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
+ smp_mb__after_clear_bit();
+ wake_up_bit(bitlock, NFS_INO_INVALIDATING);
out:
return ret;
}