Re: [PATCH] pack-objects: protect against disappearing packs

[Jeff King <peff@peff.net>]

On Thu, Oct 13, 2011 at 09:23:20PM -0400, Jeff King wrote:

> diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
> index 2b18de5..8681ccd 100644
> --- a/builtin/pack-objects.c
> +++ b/builtin/pack-objects.c
> @@ -804,6 +804,10 @@ static int add_object_entry(const unsigned char *sha1, enum object_type type,
>  		off_t offset = find_pack_entry_one(sha1, p);
>  		if (offset) {
>  			if (!found_pack) {
> +				if (!is_pack_valid(p)) {
> +					error("packfile %s cannot be accessed", p->pack_name);
> +					continue;
> +				}

This message is modeled after the one in find_pack_entry. However,
they're not really errors, since we will try to find the object
elsewhere (and generally succeed). So the messages could just go away.
Though they can also alert you to something fishy going on (like a
packfile with bad permissions). But perhaps we should downgrade them
like this:

-- >8 --
Subject: [PATCH] downgrade "packfile cannot be accessed" errors to warnings

These can happen if another process simultaneously prunes a
pack. But that is not usually an error condition, because a
properly-running prune should have repacked the object into
a new pack. So we will notice that the pack has disappeared
unexpectedly, print a message, try other packs (possibly
after re-scanning the list of packs), and find it in the new
pack.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/pack-objects.c |    2 +-
 sha1_file.c            |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 8681ccd..ba3705d 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -805,7 +805,7 @@ static int add_object_entry(const unsigned char *sha1, enum object_type type,
 		if (offset) {
 			if (!found_pack) {
 				if (!is_pack_valid(p)) {
-					error("packfile %s cannot be accessed", p->pack_name);
+					warning("packfile %s cannot be accessed", p->pack_name);
 					continue;
 				}
 				found_offset = offset;
diff --git a/sha1_file.c b/sha1_file.c
index a22c5b4..27f3b9b 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -2038,7 +2038,7 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
 			 * was loaded!
 			 */
 			if (!is_pack_valid(p)) {
-				error("packfile %s cannot be accessed", p->pack_name);
+				warning("packfile %s cannot be accessed", p->pack_name);
 				goto next;
 			}
 			e->offset = offset;
-- 
1.7.6.4.37.g43b58b