diff options
| author | Trond Myklebust <trond.myklebust@primarydata.com> | 2015-02-26 16:09:04 -0500 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2015-03-01 23:23:05 -0500 |
| commit | f044636d972246d451e06226cc1675d5da389762 (patch) | |
| tree | 7fbfe0ffc4f5a5b3f9ccf56de8fe887c7394027c /fs/nfs/inode.c | |
| parent | 140e049c64ce848392adbf4678983ecc76888dde (diff) | |
NFS: Add attribute update barriers to nfs_setattr_update_inode()
Ensure that other operations which raced with our setattr RPC call
cannot revert the file attribute changes that were made on the server.
To do so, we artificially bump the attribute generation counter on
the inode so that all calls to nfs_fattr_init() that precede ours
will be dropped.
The motivation for the patch came from Chuck Lever's reports of readaheads
racing with truncate operations and causing the file size to be reverted.
Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'fs/nfs/inode.c')
| -rw-r--r-- | fs/nfs/inode.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index b0cbc1ba82da..3a2d127de499 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -556,6 +556,7 @@ EXPORT_SYMBOL_GPL(nfs_setattr); * This is a copy of the common vmtruncate, but with the locking * corrected to take into account the fact that NFS requires * inode->i_size to be updated under the inode->i_lock. + * Note: must be called with inode->i_lock held! */ static int nfs_vmtruncate(struct inode * inode, loff_t offset) { @@ -565,14 +566,14 @@ static int nfs_vmtruncate(struct inode * inode, loff_t offset) if (err) goto out; - spin_lock(&inode->i_lock); i_size_write(inode, offset); /* Optimisation */ if (offset == 0) NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_DATA; - spin_unlock(&inode->i_lock); + spin_unlock(&inode->i_lock); truncate_pagecache(inode, offset); + spin_lock(&inode->i_lock); out: return err; } @@ -585,10 +586,15 @@ out: * Note: we do this in the *proc.c in order to ensure that * it works for things like exclusive creates too. */ -void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr) +void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, + struct nfs_fattr *fattr) { + /* Barrier: bump the attribute generation count. */ + nfs_fattr_set_barrier(fattr); + + spin_lock(&inode->i_lock); + NFS_I(inode)->attr_gencount = fattr->gencount; if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) { - spin_lock(&inode->i_lock); if ((attr->ia_valid & ATTR_MODE) != 0) { int mode = attr->ia_mode & S_IALLUGO; mode |= inode->i_mode & ~S_IALLUGO; @@ -600,12 +606,13 @@ void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr) inode->i_gid = attr->ia_gid; nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL); - spin_unlock(&inode->i_lock); } if ((attr->ia_valid & ATTR_SIZE) != 0) { nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC); nfs_vmtruncate(inode, attr->ia_size); } + nfs_update_inode(inode, fattr); + spin_unlock(&inode->i_lock); } EXPORT_SYMBOL_GPL(nfs_setattr_update_inode); |