Hi Ted, On Sat, Oct 27, 2012 at 06:16:26PM -0400, Theodore Ts'o wrote: > On Fri, Oct 26, 2012 at 10:24:23PM +0000, Luck, Tony wrote: > > > Well, we could set a new attribute bit on the file which indicates > > > that the file has been corrupted, and this could cause any attempts to > > > open the file to return some error until the bit has been cleared. > > > > That sounds a lot better than renaming/moving the file. > > What I would recommend is adding a > > #define FS_CORRUPTED_FL 0x01000000 /* File is corrupted */ > > ... and which could be accessed and cleared via the lsattr and chattr > programs. Thank you for the info. This could help my next work. > > > Application programs could also get very confused when any attempt to > > > open or read from a file suddenly returned some new error code (EIO, > > > or should we designate a new errno code for this purpose, so there is > > > a better indication of what the heck was going on?) > > > > EIO sounds wrong ... but it is perhaps the best of the existing codes. Adding > > a new one is also challenging too. > > I think we really need a different error code from EIO; it's already > horribly overloaded already, and if this is new behavior when the > customers get confused and call up the distribution help desk, they > won't thank us if we further overload EIO. This is abusing one of the > System V stream errno's, but no one else is using it: > > #define EADV 68 /* Advertise error */ > > I note that we've already added a new error code: > > #define EHWPOISON 133 /* Memory page has hardware error */ > > ... although the glibc shipping with Debian testing hasn't been taught > what it is, so strerror(EHWPOISON) returns "Unknown error 133". We > could simply allow open(2) and stat(2) return this error, although I > wonder if we're just better off defining a new error code. Whether we use EIO or EHWPOISON seems to be controversial. Andi likes to use EIO because we can handle memory errors and legacy I/O errors in the similar and integrated manner. But personally, it's OK for me to use EHWPOISON. Obviously defining this error code in glibc is a necessary step if we go in this direction. Thanks, Naoya -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>