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authorLinus Torvalds <torvalds@linux-foundation.org>2014-01-31 15:39:07 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-31 15:39:07 -0800
commit8a1f006ad302ea178aefb1f8c67e679c696289e9 (patch)
tree8ba312b39070556d2062a9f90b1a7fa394041d78 /fs/nfs/inode.c
parent14864a52cd8189e8567df8351d9fc7e435133abd (diff)
parenta1800acaf7d1c2bf6d68b9a8f4ab8560cc66555a (diff)
Merge tag 'nfs-for-3.14-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust: "Highlights: - Fix several races in nfs_revalidate_mapping - NFSv4.1 slot leakage in the pNFS files driver - Stable fix for a slot leak in nfs40_sequence_done - Don't reject NFSv4 servers that support ACLs with only ALLOW aces" * tag 'nfs-for-3.14-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: nfs: initialize the ACL support bits to zero. NFSv4.1: Cleanup NFSv4.1: Clean up nfs41_sequence_done NFSv4: Fix a slot leak in nfs40_sequence_done NFSv4.1 free slot before resending I/O to MDS nfs: add memory barriers around NFS_INO_INVALID_DATA and NFS_INO_INVALIDATING NFS: Fix races in nfs_revalidate_mapping sunrpc: turn warn_gssd() log message into a dprintk() NFS: fix the handling of NFS_INO_INVALID_DATA flag in nfs_revalidate_mapping nfs: handle servers that support only ALLOW ACE type.
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;
}