From 88309aae3ddb62e6d02a8f1002a4f4fc41b423ad Mon Sep 17 00:00:00 2001 From: Mike Marshall Date: Wed, 23 Sep 2015 16:48:40 -0400 Subject: [PATCH] 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: Mike Marshall --- fs/orangefs/dir.c | 131 ++++++++++++++++++------------------------------- fs/orangefs/protocol.h | 1 + 2 files changed, 50 insertions(+), 82 deletions(-) diff --git a/fs/orangefs/dir.c b/fs/orangefs/dir.c index c126c0f..3870e78 100644 --- a/fs/orangefs/dir.c +++ b/fs/orangefs/dir.c @@ -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; @@ -129,11 +119,11 @@ 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", - __func__, - lld(ctx->pos), - llu(*ptoken)); + gossip_debug(GOSSIP_DIR_DEBUG, + "%s: ctx->pos:%lld, ptoken = %llu\n", + __func__, + lld(ctx->pos), + llu(*ptoken)); pos = (__u64) ctx->pos; @@ -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 @@ get_new_buffer_index: } if (bytes_decoded != new_op->downcall.trailer_size) { - gossip_err("pvfs2_readdir: # bytes decoded (%ld) != trailer size (%ld)\n", - bytes_decoded, - (long)new_op->downcall.trailer_size); + 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 @@ get_new_buffer_index: __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 @@ get_new_buffer_index: __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 */ + /* + * we ran all the way through the last batch, set up for + * getting another batch... + */ + if (ret) { *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 - */ - 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)); + ctx->pos = PVFS_ITERATE_NEXT; } /* @@ -330,17 +303,11 @@ get_new_buffer_index: */ 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: diff --git a/fs/orangefs/protocol.h b/fs/orangefs/protocol.h index f571be2..cae9cc0 100644 --- a/fs/orangefs/protocol.h +++ b/fs/orangefs/protocol.h @@ -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 -- 2.7.4