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Diffstat (limited to 'fs/nfs/dir.c')
-rw-r--r--fs/nfs/dir.c90
1 files changed, 84 insertions, 6 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 0fb37fac88c9..6b3c547154b3 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -139,12 +139,19 @@ struct nfs_cache_array {
struct nfs_cache_array_entry array[0];
};
+struct readdirvec {
+ unsigned long nr;
+ unsigned long index;
+ struct page *pages[NFS_MAX_READDIR_RAPAGES];
+};
+
typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, bool);
typedef struct {
struct file *file;
struct page *page;
struct dir_context *ctx;
unsigned long page_index;
+ struct readdirvec pvec;
u64 *dir_cookie;
u64 last_cookie;
loff_t current_index;
@@ -524,6 +531,10 @@ int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *en
struct nfs_cache_array *array;
unsigned int count = 0;
int status;
+ int max_rapages = NFS_MAX_READDIR_RAPAGES;
+
+ desc->pvec.index = desc->page_index;
+ desc->pvec.nr = 0;
scratch = alloc_page(GFP_KERNEL);
if (scratch == NULL)
@@ -548,20 +559,40 @@ int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *en
if (desc->plus)
nfs_prime_dcache(file_dentry(desc->file), entry);
- status = nfs_readdir_add_to_array(entry, page);
+ status = nfs_readdir_add_to_array(entry, desc->pvec.pages[desc->pvec.nr]);
+ if (status == -ENOSPC) {
+ desc->pvec.nr++;
+ if (desc->pvec.nr == max_rapages)
+ break;
+ status = nfs_readdir_add_to_array(entry, desc->pvec.pages[desc->pvec.nr]);
+ }
if (status != 0)
break;
} while (!entry->eof);
+ /*
+ * page and desc->pvec.pages[0] are valid, don't need to check
+ * whether or not to be NULL.
+ */
+ copy_highpage(page, desc->pvec.pages[0]);
+
out_nopages:
if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
- array = kmap(page);
+ array = kmap_atomic(desc->pvec.pages[desc->pvec.nr]);
array->eof_index = array->size;
status = 0;
- kunmap(page);
+ kunmap_atomic(array);
}
put_page(scratch);
+
+ /*
+ * desc->pvec.nr > 0 means at least one page was completely filled,
+ * we should return -ENOSPC. Otherwise function
+ * nfs_readdir_xdr_to_array will enter infinite loop.
+ */
+ if (desc->pvec.nr > 0)
+ return -ENOSPC;
return status;
}
@@ -595,6 +626,24 @@ out_freepages:
return -ENOMEM;
}
+/*
+ * nfs_readdir_rapages_init initialize rapages by nfs_cache_array structure.
+ */
+static
+void nfs_readdir_rapages_init(nfs_readdir_descriptor_t *desc)
+{
+ struct nfs_cache_array *array;
+ int max_rapages = NFS_MAX_READDIR_RAPAGES;
+ int index;
+
+ for (index = 0; index < max_rapages; index++) {
+ array = kmap_atomic(desc->pvec.pages[index]);
+ memset(array, 0, sizeof(struct nfs_cache_array));
+ array->eof_index = -1;
+ kunmap_atomic(array);
+ }
+}
+
static
int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
{
@@ -605,6 +654,12 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
int status = -ENOMEM;
unsigned int array_size = ARRAY_SIZE(pages);
+ /*
+ * This means we hit readdir rdpages miss, the preallocated rdpages
+ * are useless, the preallocate rdpages should be reinitialized.
+ */
+ nfs_readdir_rapages_init(desc);
+
entry.prev_cookie = 0;
entry.cookie = desc->last_cookie;
entry.eof = 0;
@@ -664,9 +719,24 @@ int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)
struct inode *inode = file_inode(desc->file);
int ret;
- ret = nfs_readdir_xdr_to_array(desc, page, inode);
- if (ret < 0)
- goto error;
+ /*
+ * If desc->page_index in range desc->pvec.index and
+ * desc->pvec.index + desc->pvec.nr, we get readdir cache hit.
+ */
+ if (desc->page_index >= desc->pvec.index &&
+ desc->page_index < (desc->pvec.index + desc->pvec.nr)) {
+ /*
+ * page and desc->pvec.pages[x] are valid, don't need to check
+ * whether or not to be NULL.
+ */
+ copy_highpage(page, desc->pvec.pages[desc->page_index - desc->pvec.index]);
+ ret = 0;
+ } else {
+ ret = nfs_readdir_xdr_to_array(desc, page, inode);
+ if (ret < 0)
+ goto error;
+ }
+
SetPageUptodate(page);
if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {
@@ -831,6 +901,7 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
*desc = &my_desc;
struct nfs_open_dir_context *dir_ctx = file->private_data;
int res = 0;
+ int max_rapages = NFS_MAX_READDIR_RAPAGES;
dfprintk(FILE, "NFS: readdir(%pD2) starting at cookie %llu\n",
file, (long long)ctx->pos);
@@ -850,6 +921,12 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
desc->decode = NFS_PROTO(inode)->decode_dirent;
desc->plus = nfs_use_readdirplus(inode, ctx);
+ res = nfs_readdir_alloc_pages(desc->pvec.pages, max_rapages);
+ if (res < 0)
+ return -ENOMEM;
+
+ nfs_readdir_rapages_init(desc);
+
if (ctx->pos == 0 || nfs_attribute_cache_expired(inode))
res = nfs_revalidate_mapping(inode, file->f_mapping);
if (res < 0)
@@ -885,6 +962,7 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
break;
} while (!desc->eof);
out:
+ nfs_readdir_free_pages(desc->pvec.pages, max_rapages);
if (res > 0)
res = 0;
dfprintk(FILE, "NFS: readdir(%pD2) returns %d\n", file, res);