Re: [ntfsd] Bugcheck 19 with Adobe Indesign

IMHO many applications still use MAX_PATH and can’t handle anything longer

Sent from Surface Pro

From: Craig Barkhouse
Sent: ‎Friday‎, ‎March‎ ‎27‎, ‎2015 ‎5‎:‎30‎ ‎PM
To: Windows File Systems Devs Interest List

Correct, the maximum component length in NTFS is 255 characters. That’s for a file or a directory.

The maximum component length can vary from file system to file system. The following link mentions this and also has other good information about file names and path names:

https://msdn.microsoft.com/en-us/library/aa365247.aspx

-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of Phil Barila
Sent: Friday, March 27, 2015 7:53 AM
To: Windows File Systems Devs Interest List
Subject: RE: Re:[ntfsd] Bugcheck 19 with Adobe Indesign

The 32K limit is the length of the entire path, not a single element. The full path has to fit inside a UNICODE_STRING. I think I remember discovering empirically that NTFS limits a directory to 255 characters, but that was quite a while ago, and I wouldn’t testify to that being absolutely true without repeating some experiments that I don’t have readily to hand.

Both explorer and cmd.exe try pretty hard to stay under the 260 char full path limit. You can use cmd to create a really deep path by renaming a directory to a really long name, but you can’t CD into it once you’ve created it. Once you’ve created a path that exceeds 260 chars total, in order to remove it from the FS, you have to reverse the process by renaming each long element, until the longest full path in the tree is shorter than 260.

I haven’t tried anything like that on anything newer than Windows 7.

Phil

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-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of Rod Widdowson
Sent: Friday, March 27, 2015 4:00 AM
To: Windows File Systems Devs Interest List
Subject: Re:[ntfsd] Bugcheck 19 with Adobe Indesign

It overrides the MS guidelines for having 260 characters in a file path.

That is a Win32 limitation (I think). The system API allows for any path name that can be described by a UNICODE_STRING so that max path is 2^15
32,000 characters or so.

Of course you can construct paths which are longer that that by doing relative opens in which each file name is 32K characters long.

I, for one, would be astonished if NTFS (or any other Microsoft kernel
product) didn’t handle this.

Of course once you have one of these there’s not much you can do with it (for instance I would be somewhat surprised if Explorer managed to do anything sensible)

Can we expect valid file names to be longer than 260 characters?
Yes, you should always assume that someone (and hopefully it will be someone in your test team) will push the System service APIs to the extreme.

/Rod


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