From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cantor2.suse.de ([195.135.220.15]:54506 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932198Ab2EUVtz (ORCPT ); Mon, 21 May 2012 17:49:55 -0400 From: Mark Fasheh To: linux-btrfs@vger.kernel.org Cc: Chris Mason , Jan Schmidt , Mark Fasheh , Mark Fasheh Subject: [PATCH 3/3] btrfs: extended inode refs Date: Mon, 21 May 2012 14:46:21 -0700 Message-Id: <1337636781-12575-4-git-send-email-mfasheh@suse.de> In-Reply-To: <1337636781-12575-1-git-send-email-mfasheh@suse.de> References: <1337636781-12575-1-git-send-email-mfasheh@suse.de> Sender: linux-btrfs-owner@vger.kernel.org List-ID: From: Mark Fasheh The iterate_irefs in backref.c is used to build path components from inode refs. This patch adds code to iterate extended refs as well. I had modify the callback function signature to abstract out some of the differences between ref structures. iref_to_path() also needed similar changes. Signed-off-by: Mark Fasheh --- fs/btrfs/backref.c | 144 +++++++++++++++++++++++++++++++++++++++++++--------- fs/btrfs/backref.h | 2 - 2 files changed, 119 insertions(+), 27 deletions(-) diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index c97240a..d88fa49 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -22,6 +22,7 @@ #include "ulist.h" #include "transaction.h" #include "delayed-ref.h" +#include "locking.h" /* * this structure records all encountered refs on the way up to the root @@ -940,34 +941,35 @@ int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, * value will be smaller than dest. callers must check this! */ static char *iref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, - struct btrfs_inode_ref *iref, - struct extent_buffer *eb_in, u64 parent, - char *dest, u32 size) + u32 name_len, unsigned long name_off, + struct extent_buffer *eb_in, u64 parent, + char *dest, u32 size) { - u32 len; int slot; u64 next_inum; int ret; s64 bytes_left = size - 1; struct extent_buffer *eb = eb_in; struct btrfs_key found_key; + struct btrfs_inode_ref *iref; if (bytes_left >= 0) dest[bytes_left] = '\0'; while (1) { - len = btrfs_inode_ref_name_len(eb, iref); - bytes_left -= len; + bytes_left -= name_len; if (bytes_left >= 0) read_extent_buffer(eb, dest + bytes_left, - (unsigned long)(iref + 1), len); + name_off, name_len); if (eb != eb_in) free_extent_buffer(eb); + ret = inode_ref_info(parent, 0, fs_root, path, &found_key); if (ret > 0) ret = -ENOENT; if (ret) break; + next_inum = found_key.offset; /* regular exit ahead */ @@ -980,8 +982,11 @@ static char *iref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, if (eb != eb_in) atomic_inc(&eb->refs); btrfs_release_path(path); - iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); + + name_len = btrfs_inode_ref_name_len(eb, iref); + name_off = (unsigned long)(iref + 1); + parent = next_inum; --bytes_left; if (bytes_left >= 0) @@ -1294,9 +1299,12 @@ int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, return ret; } -static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, - struct btrfs_path *path, - iterate_irefs_t *iterate, void *ctx) +typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, + struct extent_buffer *eb, void *ctx); + +static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, + struct btrfs_path *path, + iterate_irefs_t *iterate, void *ctx) { int ret; int slot; @@ -1312,7 +1320,7 @@ static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, while (1) { ret = inode_ref_info(inum, parent ? parent+1 : 0, fs_root, path, - &found_key); + &found_key); if (ret < 0) break; if (ret) { @@ -1326,8 +1334,11 @@ static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, eb = path->nodes[0]; /* make sure we can use eb after releasing the path */ atomic_inc(&eb->refs); + btrfs_tree_read_lock(eb); + btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); btrfs_release_path(path); + item = btrfs_item_nr(eb, slot); iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); @@ -1338,15 +1349,81 @@ static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, "tree %llu\n", cur, (unsigned long long)found_key.objectid, (unsigned long long)fs_root->objectid); - ret = iterate(parent, iref, eb, ctx); - if (ret) { - free_extent_buffer(eb); + ret = iterate(parent, name_len, + (unsigned long)(iref + 1),eb, ctx); + if (ret) break; - } len = sizeof(*iref) + name_len; iref = (struct btrfs_inode_ref *)((char *)iref + len); } + btrfs_tree_read_unlock_blocking(eb); + free_extent_buffer(eb); + } + + btrfs_release_path(path); + + return ret; +} + +static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, + struct btrfs_path *path, + iterate_irefs_t *iterate, void *ctx) +{ + int ret; + int slot; + u64 offset = 0; + u64 parent; + int found = 0; + struct extent_buffer *eb; + struct btrfs_inode_extref *extref; + struct extent_buffer *leaf; + u32 item_size; + u32 cur_offset; + unsigned long ptr; + + while (1) { + ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, + &offset); + if (ret < 0) + break; + if (ret) { + ret = found ? 0 : -ENOENT; + break; + } + ++found; + + slot = path->slots[0]; + eb = path->nodes[0]; + /* make sure we can use eb after releasing the path */ + atomic_inc(&eb->refs); + + btrfs_tree_read_lock(eb); + btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); + btrfs_release_path(path); + + leaf = path->nodes[0]; + item_size = btrfs_item_size_nr(leaf, path->slots[0]); + ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); + cur_offset = 0; + + while (cur_offset < item_size) { + u32 name_len; + + extref = (struct btrfs_inode_extref *)(ptr + cur_offset); + parent = btrfs_inode_extref_parent(eb, extref); + name_len = btrfs_inode_extref_name_len(eb, extref); + ret = iterate(parent, name_len, + (unsigned long)&extref->name, eb, ctx); + if (ret) + break; + + cur_offset += btrfs_inode_extref_name_len(leaf, extref); + cur_offset += sizeof(*extref); + } + btrfs_tree_read_unlock_blocking(eb); free_extent_buffer(eb); + + offset++; } btrfs_release_path(path); @@ -1354,12 +1431,32 @@ static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, return ret; } +static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, + struct btrfs_path *path, iterate_irefs_t *iterate, + void *ctx) +{ + int ret; + int found_refs = 0; + + ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); + if (!ret) + ++found_refs; + else if (ret != -ENOENT) + return ret; + + ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); + if (ret == -ENOENT && found_refs) + return 0; + + return ret; +} + /* * returns 0 if the path could be dumped (probably truncated) * returns <0 in case of an error */ -static int inode_to_path(u64 inum, struct btrfs_inode_ref *iref, - struct extent_buffer *eb, void *ctx) +static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, + struct extent_buffer *eb, void *ctx) { struct inode_fs_paths *ipath = ctx; char *fspath; @@ -1372,20 +1469,17 @@ static int inode_to_path(u64 inum, struct btrfs_inode_ref *iref, ipath->fspath->bytes_left - s_ptr : 0; fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; - fspath = iref_to_path(ipath->fs_root, ipath->btrfs_path, iref, eb, - inum, fspath_min, bytes_left); + fspath = iref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, + name_off, eb, inum, fspath_min, + bytes_left); if (IS_ERR(fspath)) return PTR_ERR(fspath); if (fspath > fspath_min) { - pr_debug("path resolved: %s\n", fspath); ipath->fspath->val[i] = (u64)(unsigned long)fspath; ++ipath->fspath->elem_cnt; ipath->fspath->bytes_left = fspath - fspath_min; } else { - pr_debug("missed path, not enough space. missing bytes: %lu, " - "constructed so far: %s\n", - (unsigned long)(fspath_min - fspath), fspath_min); ++ipath->fspath->elem_missed; ipath->fspath->bytes_missing += fspath_min - fspath; ipath->fspath->bytes_left = 0; @@ -1407,7 +1501,7 @@ static int inode_to_path(u64 inum, struct btrfs_inode_ref *iref, int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) { return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, - inode_to_path, ipath); + inode_to_path, ipath); } /* diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h index 8586d1b..649a220 100644 --- a/fs/btrfs/backref.h +++ b/fs/btrfs/backref.h @@ -30,8 +30,6 @@ struct inode_fs_paths { typedef int (iterate_extent_inodes_t)(u64 inum, u64 offset, u64 root, void *ctx); -typedef int (iterate_irefs_t)(u64 parent, struct btrfs_inode_ref *iref, - struct extent_buffer *eb, void *ctx); int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, struct btrfs_path *path); -- 1.7.7