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NFS: Avoid duplicate uncached readdir calls on eof

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If we've reached the end of the directory, then cache that information
in the context so that we don't need to do an uncached readdir in order
to rediscover that fact.

Fixes: 794092c57f ("NFS: Do uncached readdir when we're seeking a cookie in an empty page cache")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Trond Myklebust 2022-01-18 22:10:52 -05:00 committed by Anna Schumaker
parent ce292d8faf
commit e1d2699b96
2 changed files with 16 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
fs/nfs/dir.c
View File

@ -80,6 +80,7 @@ static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir
ctx->dir_cookie = 0;
ctx->dup_cookie = 0;
ctx->page_index = 0;
ctx->eof = false;
spin_lock(&dir->i_lock);
if (list_empty(&nfsi->open_files) &&
(nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER))
@ -168,6 +169,7 @@ struct nfs_readdir_descriptor {
unsigned int cache_entry_index;
signed char duped;
bool plus;
bool eob;
bool eof;
};
@ -989,7 +991,7 @@ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc,
ent = &array->array[i];
if (!dir_emit(desc->ctx, ent->name, ent->name_len,
nfs_compat_user_ino64(ent->ino), ent->d_type)) {
desc->eof = true;
desc->eob = true;
break;
}
memcpy(desc->verf, verf, sizeof(desc->verf));
@ -1005,7 +1007,7 @@ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc,
desc->duped = 1;
}
if (array->page_is_eof)
desc->eof = true;
desc->eof = !desc->eob;
kunmap(desc->page);
dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %llu\n",
@ -1048,7 +1050,7 @@ static int uncached_readdir(struct nfs_readdir_descriptor *desc)
status = nfs_readdir_xdr_to_array(desc, desc->verf, verf, arrays, sz);
for (i = 0; !desc->eof && i < sz && arrays[i]; i++) {
for (i = 0; !desc->eob && i < sz && arrays[i]; i++) {
desc->page = arrays[i];
nfs_do_filldir(desc, verf);
}
@ -1107,9 +1109,15 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
desc->duped = dir_ctx->duped;
page_index = dir_ctx->page_index;
desc->attr_gencount = dir_ctx->attr_gencount;
desc->eof = dir_ctx->eof;
memcpy(desc->verf, dir_ctx->verf, sizeof(desc->verf));
spin_unlock(&file->f_lock);
if (desc->eof) {
res = 0;
goto out_free;
}
if (test_and_clear_bit(NFS_INO_FORCE_READDIR, &nfsi->flags) &&
list_is_singular(&nfsi->open_files))
invalidate_mapping_pages(inode->i_mapping, page_index + 1, -1);
@ -1143,7 +1151,7 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
nfs_do_filldir(desc, nfsi->cookieverf);
nfs_readdir_page_unlock_and_put_cached(desc);
} while (!desc->eof);
} while (!desc->eob && !desc->eof);
spin_lock(&file->f_lock);
dir_ctx->dir_cookie = desc->dir_cookie;
@ -1151,9 +1159,10 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
dir_ctx->duped = desc->duped;
dir_ctx->attr_gencount = desc->attr_gencount;
dir_ctx->page_index = desc->page_index;
dir_ctx->eof = desc->eof;
memcpy(dir_ctx->verf, desc->verf, sizeof(dir_ctx->verf));
spin_unlock(&file->f_lock);
out_free:
kfree(desc);
out:
@ -1195,6 +1204,7 @@ static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
if (offset == 0)
memset(dir_ctx->verf, 0, sizeof(dir_ctx->verf));
dir_ctx->duped = 0;
dir_ctx->eof = false;
}
spin_unlock(&filp->f_lock);
return offset;

1
include/linux/nfs_fs.h
View File

@ -107,6 +107,7 @@ struct nfs_open_dir_context {
__u64 dup_cookie;
pgoff_t page_index;
signed char duped;
bool eof;
};
/*