NFS: Remove BKL requirement from attribute updates

The main problem is dealing with inode->i_size: we need to set the
inode->i_lock on all attribute updates, and so vmtruncate won't cut it.
Make an NFS-private version of vmtruncate that has the necessary locking
semantics.

The result should be that the following inode attribute updates are
protected by inode->i_lock
	nfsi->cache_validity
	nfsi->read_cache_jiffies
	nfsi->attrtimeo
	nfsi->attrtimeo_timestamp
	nfsi->change_attr
	nfsi->last_updated
	nfsi->cache_change_attribute
	nfsi->access_cache
	nfsi->access_cache_entry_lru
	nfsi->access_cache_inode_lru
	nfsi->acl_access
	nfsi->acl_default
	nfsi->nfs_page_tree
	nfsi->ncommit
	nfsi->npages
	nfsi->open_files
	nfsi->silly_list
	nfsi->acl
	nfsi->open_states
	inode->i_size
	inode->i_atime
	inode->i_mtime
	inode->i_ctime
	inode->i_nlink
	inode->i_uid
	inode->i_gid

The following is protected by dir->i_mutex
	nfsi->cookieverf

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2008-06-11 12:21:19 -04:00
parent 1b83d70703
commit a3d01454bc
2 changed files with 71 additions and 11 deletions

View file

@ -388,6 +388,62 @@ nfs_setattr(struct dentry *dentry, struct iattr *attr)
return error;
}
/**
* nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
* @inode: inode of the file used
* @offset: file offset to start truncating
*
* 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.
*/
static int nfs_vmtruncate(struct inode * inode, loff_t offset)
{
if (i_size_read(inode) < offset) {
unsigned long limit;
limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
if (limit != RLIM_INFINITY && offset > limit)
goto out_sig;
if (offset > inode->i_sb->s_maxbytes)
goto out_big;
spin_lock(&inode->i_lock);
i_size_write(inode, offset);
spin_unlock(&inode->i_lock);
} else {
struct address_space *mapping = inode->i_mapping;
/*
* truncation of in-use swapfiles is disallowed - it would
* cause subsequent swapout to scribble on the now-freed
* blocks.
*/
if (IS_SWAPFILE(inode))
return -ETXTBSY;
spin_lock(&inode->i_lock);
i_size_write(inode, offset);
spin_unlock(&inode->i_lock);
/*
* unmap_mapping_range is called twice, first simply for
* efficiency so that truncate_inode_pages does fewer
* single-page unmaps. However after this first call, and
* before truncate_inode_pages finishes, it is possible for
* private pages to be COWed, which remain after
* truncate_inode_pages finishes, hence the second
* unmap_mapping_range call must be made for correctness.
*/
unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
truncate_inode_pages(mapping, offset);
unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
}
return 0;
out_sig:
send_sig(SIGXFSZ, current, 0);
out_big:
return -EFBIG;
}
/**
* nfs_setattr_update_inode - Update inode metadata after a setattr call.
* @inode: pointer to struct inode
@ -414,8 +470,7 @@ void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
}
if ((attr->ia_valid & ATTR_SIZE) != 0) {
nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
inode->i_size = attr->ia_size;
vmtruncate(inode, attr->ia_size);
nfs_vmtruncate(inode, attr->ia_size);
}
}
@ -829,9 +884,9 @@ static void nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
if (S_ISDIR(inode->i_mode))
nfsi->cache_validity |= NFS_INO_INVALID_DATA;
}
if (inode->i_size == nfs_size_to_loff_t(fattr->pre_size) &&
if (i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size) &&
nfsi->npages == 0)
inode->i_size = nfs_size_to_loff_t(fattr->size);
i_size_write(inode, nfs_size_to_loff_t(fattr->size));
}
}
@ -972,7 +1027,7 @@ int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fa
(fattr->valid & NFS_ATTR_WCC) == 0) {
memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
fattr->pre_size = inode->i_size;
fattr->pre_size = i_size_read(inode);
fattr->valid |= NFS_ATTR_WCC;
}
return nfs_post_op_update_inode(inode, fattr);
@ -1057,7 +1112,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
/* Do we perhaps have any outstanding writes, or has
* the file grown beyond our last write? */
if (nfsi->npages == 0 || new_isize > cur_isize) {
inode->i_size = new_isize;
i_size_write(inode, new_isize);
invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
}
dprintk("NFS: isize change on server for file %s/%ld\n",

View file

@ -133,16 +133,21 @@ static struct nfs_page *nfs_page_find_request(struct page *page)
static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
{
struct inode *inode = page->mapping->host;
loff_t end, i_size = i_size_read(inode);
pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
loff_t end, i_size;
pgoff_t end_index;
spin_lock(&inode->i_lock);
i_size = i_size_read(inode);
end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
if (i_size > 0 && page->index < end_index)
return;
goto out;
end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count);
if (i_size >= end)
return;
nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
goto out;
i_size_write(inode, end);
nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
out:
spin_unlock(&inode->i_lock);
}
/* A writeback failed: mark the page as bad, and invalidate the page cache */