-------------------------------------------- On Fri, 20/9/13, Vyacheslav Dubeyko <slava@xxxxxxxxxxx> wrote: Subject: [PATCH 3/3] hfsplus: implement attributes file creation functionality To: "Linux FS devel list" <linux-fsdevel@xxxxxxxxxxxxxxx> Cc: "Al Viro" <viro@xxxxxxxxxxxxxxxxxx>, "Christoph Hellwig" <hch@xxxxxxxxxxxxx>, "Hin-Tak Leung" <htl10@xxxxxxxxxxxxxxxxxxxxx>, "Andrew Morton" <akpm@xxxxxxxxxxxxxxxxxxxx> Date: Friday, 20 September, 2013, 11:04 From: Vyacheslav Dubeyko <slava@xxxxxxxxxxx> Subject: [PATCH 3/3] hfsplus: implement attributes file creation functionality This patch implements functionality of creation AttributesFile metadata file on HFS+ volume in the case of absence of it. It makes trying to open AttributesFile's B-tree during mount of HFS+ volume. If HFS+ volume hasn't AttributesFile then a pointer on AttributesFile's B-tree keeps as NULL. Thereby, when it is discovered absence of AttributesFile on HFS+ volume in the begin of xattr creation operation then AttributesFile will be created. The creation of AttributesFile will have success in the case of availability (2 * clump) free blocks on HFS+ volume. Otherwise, creation operation is ended with error (-ENOSPC). Signed-off-by: Vyacheslav Dubeyko <slava@xxxxxxxxxxx> CC: Al Viro <viro@xxxxxxxxxxxxxxxxxx> CC: Christoph Hellwig <hch@xxxxxxxxxxxxx> CC: Hin-Tak Leung <htl10@xxxxxxxxxxxxxxxxxxxxx> --- Acked-by: Hin-Tak Leung <htl10@xxxxxxxxxxxxxxxxxxxxx> The changelog isn't quite correct/precise. According to the code (my reading and understanding of it), The AttributesFile is created on first need, i.e. when the first-ever attribute is set. The changelog sounds as if an empty one might be created if missing, on mount. The latter would be somewhat undesirable, as a user might just keep a particular disk quite full but contain entirely of plain no-attribute files, and have no need of a big AttributesFile ever, and suddenly find a disk throwing an previously-not-seen error on use. Usage on linux would mostly be standalone xsetattr; the other common use would be the copy of a file plus its attribute, from another fs which supports this, to an hfs+ fs without a AttributesFile yet. How does hfs+ under Mac OS behaves vs current Linux vs patched Linux? (silently dropping attribute/drop attribute with warning/error/etc ?) Hin-Tak -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
