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authorTrond Myklebust <Trond.Myklebust@netapp.com>2008-06-11 12:21:19 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2008-07-15 18:10:51 -0400
commita3d01454bc58b5a211ef64a7670572a40b71e682 (patch)
tree68c1ba383fb2c6702a8cc02bc81d51da6fb2920b
parent1b83d707032a1be40a60ed0a9bd841662cc04a5d (diff)
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>
-rw-r--r--fs/nfs/inode.c67
-rw-r--r--fs/nfs/write.c15
2 files changed, 71 insertions, 11 deletions
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 2c23d067e2a6..3adabd154779 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -389,6 +389,62 @@ nfs_setattr(struct dentry *dentry, struct iattr *attr)
389} 389}
390 390
391/** 391/**
392 * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
393 * @inode: inode of the file used
394 * @offset: file offset to start truncating
395 *
396 * This is a copy of the common vmtruncate, but with the locking
397 * corrected to take into account the fact that NFS requires
398 * inode->i_size to be updated under the inode->i_lock.
399 */
400static int nfs_vmtruncate(struct inode * inode, loff_t offset)
401{
402 if (i_size_read(inode) < offset) {
403 unsigned long limit;
404
405 limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
406 if (limit != RLIM_INFINITY && offset > limit)
407 goto out_sig;
408 if (offset > inode->i_sb->s_maxbytes)
409 goto out_big;
410 spin_lock(&inode->i_lock);
411 i_size_write(inode, offset);
412 spin_unlock(&inode->i_lock);
413 } else {
414 struct address_space *mapping = inode->i_mapping;
415
416 /*
417 * truncation of in-use swapfiles is disallowed - it would
418 * cause subsequent swapout to scribble on the now-freed
419 * blocks.
420 */
421 if (IS_SWAPFILE(inode))
422 return -ETXTBSY;
423 spin_lock(&inode->i_lock);
424 i_size_write(inode, offset);
425 spin_unlock(&inode->i_lock);
426
427 /*
428 * unmap_mapping_range is called twice, first simply for
429 * efficiency so that truncate_inode_pages does fewer
430 * single-page unmaps. However after this first call, and
431 * before truncate_inode_pages finishes, it is possible for
432 * private pages to be COWed, which remain after
433 * truncate_inode_pages finishes, hence the second
434 * unmap_mapping_range call must be made for correctness.
435 */
436 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
437 truncate_inode_pages(mapping, offset);
438 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
439 }
440 return 0;
441out_sig:
442 send_sig(SIGXFSZ, current, 0);
443out_big:
444 return -EFBIG;
445}
446
447/**
392 * nfs_setattr_update_inode - Update inode metadata after a setattr call. 448 * nfs_setattr_update_inode - Update inode metadata after a setattr call.
393 * @inode: pointer to struct inode 449 * @inode: pointer to struct inode
394 * @attr: pointer to struct iattr 450 * @attr: pointer to struct iattr
@@ -414,8 +470,7 @@ void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr)
414 } 470 }
415 if ((attr->ia_valid & ATTR_SIZE) != 0) { 471 if ((attr->ia_valid & ATTR_SIZE) != 0) {
416 nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC); 472 nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
417 inode->i_size = attr->ia_size; 473 nfs_vmtruncate(inode, attr->ia_size);
418 vmtruncate(inode, attr->ia_size);
419 } 474 }
420} 475}
421 476
@@ -829,9 +884,9 @@ static void nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
829 if (S_ISDIR(inode->i_mode)) 884 if (S_ISDIR(inode->i_mode))
830 nfsi->cache_validity |= NFS_INO_INVALID_DATA; 885 nfsi->cache_validity |= NFS_INO_INVALID_DATA;
831 } 886 }
832 if (inode->i_size == nfs_size_to_loff_t(fattr->pre_size) && 887 if (i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size) &&
833 nfsi->npages == 0) 888 nfsi->npages == 0)
834 inode->i_size = nfs_size_to_loff_t(fattr->size); 889 i_size_write(inode, nfs_size_to_loff_t(fattr->size));
835 } 890 }
836} 891}
837 892
@@ -972,7 +1027,7 @@ int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fa
972 (fattr->valid & NFS_ATTR_WCC) == 0) { 1027 (fattr->valid & NFS_ATTR_WCC) == 0) {
973 memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime)); 1028 memcpy(&fattr->pre_ctime, &inode->i_ctime, sizeof(fattr->pre_ctime));
974 memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime)); 1029 memcpy(&fattr->pre_mtime, &inode->i_mtime, sizeof(fattr->pre_mtime));
975 fattr->pre_size = inode->i_size; 1030 fattr->pre_size = i_size_read(inode);
976 fattr->valid |= NFS_ATTR_WCC; 1031 fattr->valid |= NFS_ATTR_WCC;
977 } 1032 }
978 return nfs_post_op_update_inode(inode, fattr); 1033 return nfs_post_op_update_inode(inode, fattr);
@@ -1057,7 +1112,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1057 /* Do we perhaps have any outstanding writes, or has 1112 /* Do we perhaps have any outstanding writes, or has
1058 * the file grown beyond our last write? */ 1113 * the file grown beyond our last write? */
1059 if (nfsi->npages == 0 || new_isize > cur_isize) { 1114 if (nfsi->npages == 0 || new_isize > cur_isize) {
1060 inode->i_size = new_isize; 1115 i_size_write(inode, new_isize);
1061 invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA; 1116 invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
1062 } 1117 }
1063 dprintk("NFS: isize change on server for file %s/%ld\n", 1118 dprintk("NFS: isize change on server for file %s/%ld\n",
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index feca8c648766..3229e217c773 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -133,16 +133,21 @@ static struct nfs_page *nfs_page_find_request(struct page *page)
133static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count) 133static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
134{ 134{
135 struct inode *inode = page->mapping->host; 135 struct inode *inode = page->mapping->host;
136 loff_t end, i_size = i_size_read(inode); 136 loff_t end, i_size;
137 pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT; 137 pgoff_t end_index;
138 138
139 spin_lock(&inode->i_lock);
140 i_size = i_size_read(inode);
141 end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
139 if (i_size > 0 && page->index < end_index) 142 if (i_size > 0 && page->index < end_index)
140 return; 143 goto out;
141 end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count); 144 end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count);
142 if (i_size >= end) 145 if (i_size >= end)
143 return; 146 goto out;
144 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
145 i_size_write(inode, end); 147 i_size_write(inode, end);
148 nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
149out:
150 spin_unlock(&inode->i_lock);
146} 151}
147 152
148/* A writeback failed: mark the page as bad, and invalidate the page cache */ 153/* A writeback failed: mark the page as bad, and invalidate the page cache */