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authorAl Viro <viro@zeniv.linux.org.uk>2016-02-16 19:54:13 -0500
committerMike Marshall <hubcap@omnibond.com>2016-03-25 22:30:54 -0400
commit9f5e2f7f1b4bf7d0b19d88edd9425510fadbb9e4 (patch)
tree7c0ac500aa53497534eed471e7889c149876f2c5
parentfecd86aac5a7621635b61e7491f0ed73610d76fa (diff)
downloadlwn-9f5e2f7f1b4bf7d0b19d88edd9425510fadbb9e4.tar.gz
lwn-9f5e2f7f1b4bf7d0b19d88edd9425510fadbb9e4.zip
orangefs: get rid of readdir_handle_s
no point, really - we couldn't keep those across the calls of getdents(); it would be too easy to DoS, having all slots exhausted. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Mike Marshall <hubcap@omnibond.com>
-rw-r--r--fs/orangefs/dir.c93
1 files changed, 30 insertions, 63 deletions
diff --git a/fs/orangefs/dir.c b/fs/orangefs/dir.c
index 259b667f6c8f..53a411732606 100644
--- a/fs/orangefs/dir.c
+++ b/fs/orangefs/dir.c
@@ -8,11 +8,6 @@
#include "orangefs-kernel.h"
#include "orangefs-bufmap.h"
-struct readdir_handle_s {
- struct orangefs_readdir_response_s readdir_response;
- void *dents_buf;
-};
-
/*
* decode routine used by kmod to deal with the blob sent from
* userspace for readdirs. The blob contains zero or more of these
@@ -141,44 +136,6 @@ out:
return ret;
}
-static long readdir_handle_ctor(struct readdir_handle_s *rhandle, void *buf,
- size_t size)
-{
- long ret;
-
- if (buf == NULL) {
- gossip_err
- ("Invalid NULL buffer specified in readdir_handle_ctor\n");
- return -ENOMEM;
- }
- rhandle->dents_buf = buf;
- ret = decode_dirents(buf, size, &rhandle->readdir_response);
- if (ret < 0) {
- gossip_err("Could not decode readdir from buffer %ld\n", ret);
- gossip_debug(GOSSIP_DIR_DEBUG, "vfree %p\n", buf);
- vfree(buf);
- rhandle->dents_buf = NULL;
- }
- return ret;
-}
-
-static void readdir_handle_dtor(struct readdir_handle_s *rhandle)
-{
- if (rhandle == NULL)
- return;
-
- /* kfree(NULL) is safe */
- kfree(rhandle->readdir_response.dirent_array);
- rhandle->readdir_response.dirent_array = NULL;
-
- if (rhandle->dents_buf) {
- gossip_debug(GOSSIP_DIR_DEBUG, "vfree %p\n",
- rhandle->dents_buf);
- vfree(rhandle->dents_buf);
- rhandle->dents_buf = NULL;
- }
-}
-
/*
* Read directory entries from an instance of an open directory.
*/
@@ -198,7 +155,8 @@ static int orangefs_readdir(struct file *file, struct dir_context *ctx)
struct orangefs_kernel_op_s *new_op = NULL;
struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(dentry->d_inode);
int buffer_full = 0;
- struct readdir_handle_s rhandle;
+ struct orangefs_readdir_response_s readdir_response;
+ void *dents_buf;
int i = 0;
int len = 0;
ino_t current_ino = 0;
@@ -224,8 +182,7 @@ static int orangefs_readdir(struct file *file, struct dir_context *ctx)
"orangefs_readdir called on %s (pos=%llu)\n",
dentry->d_name.name, llu(pos));
- rhandle.dents_buf = NULL;
- memset(&rhandle.readdir_response, 0, sizeof(rhandle.readdir_response));
+ memset(&readdir_response, 0, sizeof(readdir_response));
new_op = op_alloc(ORANGEFS_VFS_OP_READDIR);
if (!new_op)
@@ -278,7 +235,7 @@ get_new_buffer_index:
if (ret == -EIO && op_state_purged(new_op)) {
gossip_err("%s: Client is down. Aborting readdir call.\n",
__func__);
- goto out_free_op;
+ goto out_slot;
}
if (ret < 0 || new_op->downcall.status != 0) {
@@ -287,18 +244,22 @@ get_new_buffer_index:
new_op->downcall.status);
if (ret >= 0)
ret = new_op->downcall.status;
- goto out_free_op;
+ goto out_slot;
+ }
+
+ dents_buf = new_op->downcall.trailer_buf;
+ if (dents_buf == NULL) {
+ gossip_err("Invalid NULL buffer in readdir response\n");
+ ret = -ENOMEM;
+ goto out_slot;
}
- bytes_decoded =
- readdir_handle_ctor(&rhandle,
- new_op->downcall.trailer_buf,
- new_op->downcall.trailer_size);
+ bytes_decoded = decode_dirents(dents_buf, new_op->downcall.trailer_size,
+ &readdir_response);
if (bytes_decoded < 0) {
- gossip_err("orangefs_readdir: Could not decode trailer buffer into a readdir response %d\n",
- ret);
ret = bytes_decoded;
- goto out_free_op;
+ gossip_err("Could not decode readdir from buffer %d\n", ret);
+ goto out_vfree;
}
if (bytes_decoded != new_op->downcall.trailer_size) {
@@ -345,14 +306,14 @@ get_new_buffer_index:
gossip_debug(GOSSIP_DIR_DEBUG,
"%s: dirent_outcount:%d:\n",
__func__,
- rhandle.readdir_response.orangefs_dirent_outcount);
+ readdir_response.orangefs_dirent_outcount);
for (i = ctx->pos;
- i < rhandle.readdir_response.orangefs_dirent_outcount;
+ i < readdir_response.orangefs_dirent_outcount;
i++) {
- len = rhandle.readdir_response.dirent_array[i].d_length;
- current_entry = rhandle.readdir_response.dirent_array[i].d_name;
+ len = readdir_response.dirent_array[i].d_length;
+ current_entry = readdir_response.dirent_array[i].d_name;
current_ino = orangefs_khandle_to_ino(
- &(rhandle.readdir_response.dirent_array[i].khandle));
+ &readdir_response.dirent_array[i].khandle);
gossip_debug(GOSSIP_DIR_DEBUG,
"calling dir_emit for %s with len %d"
@@ -382,14 +343,14 @@ get_new_buffer_index:
* getting another batch...
*/
if (ret) {
- *ptoken = rhandle.readdir_response.token;
+ *ptoken = readdir_response.token;
ctx->pos = ORANGEFS_ITERATE_NEXT;
}
/*
* Did we hit the end of the directory?
*/
- if (rhandle.readdir_response.token == ORANGEFS_READDIR_END &&
+ if (readdir_response.token == ORANGEFS_READDIR_END &&
!buffer_full) {
gossip_debug(GOSSIP_DIR_DEBUG,
"End of dir detected; setting ctx->pos to ORANGEFS_READDIR_END.\n");
@@ -397,7 +358,13 @@ get_new_buffer_index:
}
out_destroy_handle:
- readdir_handle_dtor(&rhandle);
+ /* kfree(NULL) is safe */
+ kfree(readdir_response.dirent_array);
+out_vfree:
+ gossip_debug(GOSSIP_DIR_DEBUG, "vfree %p\n", dents_buf);
+ vfree(dents_buf);
+out_slot:
+ orangefs_readdir_index_put(buffer_index);
out_free_op:
op_release(new_op);
gossip_debug(GOSSIP_DIR_DEBUG, "orangefs_readdir returning %d\n", ret);