Commit 88309aae authored by Mike Marshall's avatar Mike Marshall
Browse files

Orangefs: fix dir_emit code in pvfs2_readdir. 



Al Viro glanced at readdir and surmised that getdents
would misbehave the way it was written... and sure enough.

Signed-off-by: default avatarMike Marshall <hubcap@omnibond.com>
parent 4d1c4404

fs/orangefs/dir.c

+49 −82
Original line number Diff line number Diff line
@@ -95,26 +95,16 @@ static void readdir_handle_dtor(struct pvfs2_bufmap *bufmap, 


/*

 * Read directory entries from an instance of an open directory.

 *

 * \note This routine was converted for the readdir to iterate change

 *       in "struct file_operations". "converted" mostly amounts to

 *       changing occurrences of "readdir" and "filldir" in the

 *       comments to "iterate" and "dir_emit". Also filldir calls

 *       were changed to dir_emit calls.

 *

 * \param dir_emit callback function called for each entry read.

 *

 * \retval 0  when directory has been completely traversed

 * \retval >0 if we don't call dir_emit for all entries

 *

 * \note If the dir_emit call-back returns non-zero, then iterate should

 *       assume that it has had enough, and should return as well.

 */

static int pvfs2_readdir(struct file *file, struct dir_context *ctx)

{

	struct pvfs2_bufmap *bufmap = NULL;

	int ret = 0;

	int buffer_index;

	/*

	 * ptoken supports Orangefs' distributed directory logic, added

	 * in 2.9.2.

	 */

	__u64 *ptoken = file->private_data;

	__u64 pos = 0;

	ino_t ino = 0;
@@ -129,8 +119,8 @@ static int pvfs2_readdir(struct file *file, struct dir_context *ctx) 
	char *current_entry = NULL;

	long bytes_decoded;



	gossip_ldebug(GOSSIP_DIR_DEBUG,

		      "%s: ctx->pos:%lld, token = %llu\n",

	gossip_debug(GOSSIP_DIR_DEBUG,

		     "%s: ctx->pos:%lld, ptoken = %llu\n",

		     __func__,

		     lld(ctx->pos),

		     llu(*ptoken));
@@ -165,16 +155,6 @@ static int pvfs2_readdir(struct file *file, struct dir_context *ctx) 
		     __func__,

		     &new_op->upcall.req.readdir.refn.khandle);



	/*

	 * NOTE: the position we send to the readdir upcall is out of

	 * sync with ctx->pos since:

	 * 1. pvfs2 doesn't include the "." and ".." entries that are

	 *    added below.

	 * 2. the introduction of distributed directory logic makes token no

	 *    longer be related to f_pos and pos. Instead an independent

	 *    variable is used inside the function and stored in the

	 *    private_data of the file structure.

	 */

	new_op->upcall.req.readdir.token = *ptoken;



get_new_buffer_index:
@@ -238,13 +218,18 @@ static int pvfs2_readdir(struct file *file, struct dir_context *ctx) 
	}



	if (bytes_decoded != new_op->downcall.trailer_size) {

		gossip_err("pvfs2_readdir: # bytes decoded (%ld) != trailer size (%ld)\n",

		gossip_err("pvfs2_readdir: # bytes decoded (%ld) "

			   "!= trailer size (%ld)\n",

			   bytes_decoded,

			   (long)new_op->downcall.trailer_size);

		ret = -EINVAL;

		goto out_destroy_handle;

	}



	/*

	 *  pvfs2 doesn't actually store dot and dot-dot, but

	 *  we need to have them represented.

	 */

	if (pos == 0) {

		ino = get_ino_from_khandle(dentry->d_inode);

		gossip_debug(GOSSIP_DIR_DEBUG,
@@ -252,12 +237,7 @@ static int pvfs2_readdir(struct file *file, struct dir_context *ctx) 
			     __func__,

			     llu(pos));

		ret = dir_emit(ctx, ".", 1, ino, DT_DIR);

		ctx->pos++;

		gossip_ldebug(GOSSIP_DIR_DEBUG,

			      "%s: ctx->pos:%lld\n",

			      __func__,

			      lld(ctx->pos));

		pos++;

		pos += 1;

	}



	if (pos == 1) {
@@ -267,62 +247,55 @@ static int pvfs2_readdir(struct file *file, struct dir_context *ctx) 
			     __func__,

			     llu(pos));

		ret = dir_emit(ctx, "..", 2, ino, DT_DIR);

		ctx->pos++;

		gossip_ldebug(GOSSIP_DIR_DEBUG,

			      "%s: ctx->pos:%lld\n",

			      __func__,

			      lld(ctx->pos));

		pos++;

		pos += 1;

	}



	for (i = 0; i < rhandle.readdir_response.pvfs_dirent_outcount; i++) {

	/*

	 * we stored PVFS_ITERATE_NEXT in ctx->pos last time around

	 * to prevent "finding" dot and dot-dot on any iteration

	 * other than the first.

	 */

	if (ctx->pos == PVFS_ITERATE_NEXT)

		ctx->pos = 0;



	for (i = ctx->pos;

	     i < rhandle.readdir_response.pvfs_dirent_outcount;

	     i++) {

		len = rhandle.readdir_response.dirent_array[i].d_length;

		current_entry = rhandle.readdir_response.dirent_array[i].d_name;

		current_ino = pvfs2_khandle_to_ino(

			&(rhandle.readdir_response.dirent_array[i].khandle));



		gossip_debug(GOSSIP_DIR_DEBUG,

			     "calling dir_emit for %s with len %d, pos %ld\n",

			     "calling dir_emit for %s with len %d"

			     ", ctx->pos %ld\n",

			     current_entry,

			     len,

			     (unsigned long)pos);

			     (unsigned long)ctx->pos);

		/*

		 * type is unknown. We don't return object type

		 * in the dirent_array. This leaves getdents

		 * clueless about type.

		 */

		ret =

		    dir_emit(ctx, current_entry, len, current_ino, DT_UNKNOWN);

		if (!ret)

			break;

		ctx->pos++;

		gossip_ldebug(GOSSIP_DIR_DEBUG,

		gossip_debug(GOSSIP_DIR_DEBUG,

			      "%s: ctx->pos:%lld\n",

			      __func__,

			      lld(ctx->pos));



		pos++;

	}



	/* this means that all of the dir_emit calls succeeded */

	if (i == rhandle.readdir_response.pvfs_dirent_outcount) {

		/* update token */

		*ptoken = rhandle.readdir_response.token;

	} else {

		/* this means a dir_emit call failed */

		if (rhandle.readdir_response.token == PVFS_READDIR_END) {

			/*

			 * If PVFS hit end of directory, then there

			 * is no way to do math on the token that it

			 * returned. Instead we go by ctx->pos but

			 * back up to account for the artificial .

			 * and .. entries.

			 */

			ctx->pos -= 3;

		} else {

	/* 

			 * this means a dir_emit call failed. !!! need to set

			 * back to previous ctx->pos, no middle value allowed

	 * we ran all the way through the last batch, set up for

	 * getting another batch...

	 */

			pos -= (i - 1);

			ctx->pos -= (i - 1);

		}

		gossip_debug(GOSSIP_DIR_DEBUG,

			"at least one dir_emit call failed. Setting ctx->pos to: %lld\n",

			lld(ctx->pos));

	if (ret) {

		*ptoken = rhandle.readdir_response.token;

		ctx->pos = PVFS_ITERATE_NEXT;

	}



	/*
@@ -330,17 +303,11 @@ static int pvfs2_readdir(struct file *file, struct dir_context *ctx) 
	 */

	if (rhandle.readdir_response.token == PVFS_READDIR_END &&

	    !buffer_full) {

		gossip_debug(GOSSIP_DIR_DEBUG, "End of dir detected; setting ctx->pos to PVFS_READDIR_END.\n");

		gossip_debug(GOSSIP_DIR_DEBUG,

		"End of dir detected; setting ctx->pos to PVFS_READDIR_END.\n");

		ctx->pos = PVFS_READDIR_END;

	}



	gossip_debug(GOSSIP_DIR_DEBUG,

		     "pos = %llu, token = %llu"

		     ", ctx->pos should have been %lld\n",

		     llu(pos),

		     llu(*ptoken),

		     lld(ctx->pos));



out_destroy_handle:

	readdir_handle_dtor(bufmap, &rhandle);

out_free_op:

fs/orangefs/protocol.h

+1 −0
Original line number Diff line number Diff line
@@ -384,6 +384,7 @@ DECLARE_ERRNO_MAPPING() 
#define INT32_MAX (2147483647)

#define PVFS_ITERATE_START    (INT32_MAX - 1)

#define PVFS_ITERATE_END      (INT32_MAX - 2)

#define PVFS_ITERATE_NEXT     (INT32_MAX - 3)

#define PVFS_READDIR_START PVFS_ITERATE_START

#define PVFS_READDIR_END   PVFS_ITERATE_END

#define PVFS_IMMUTABLE_FL FS_IMMUTABLE_FL