what is ls trying to tell me?

Skaperen · 05-25-2021, 05:11 PM

Code:

lt2a/sr /home2/sr 4> rm -fr bar foo
lt2a/sr /home2/sr 5> echo woot >bar
lt2a/sr /home2/sr 6> ln -s bar foo
lt2a/sr /home2/sr 7> ls -dl bar foo
/bin/ls: foo: No such file or directory
-rw-r--r-- 1 sr sr 5 May 25 18:03 bar
lrwxrwxrwx 1 sr sr 3 May 25 18:03 foo -> bar
lt2a/sr /home2/sr 8> ls -dl foo
/bin/ls: foo: No such file or directory
lrwxrwxrwx 1 sr sr 3 May 25 18:03 foo -> bar
lt2a/sr /home2/sr 9>

obviously, foo exists as well as bar that it points to.

cyent · 05-25-2021, 05:43 PM

Works for me....

ls -dl bar foo
-rw-rw-r-- 1 jc jc 5 May 26 10:40 bar
lrwxrwxrwx 1 jc jc 3 May 26 10:40 foo -> bar

cyent · 05-25-2021, 05:47 PM

Relevant part of strace ls -dl bar foo...

lstat("foo", {st_mode=S_IFLNK|0777, st_size=3, ...}) = 0
lgetxattr("foo", "security.selinux", 0x56520790d920, 255) = -1 ENODATA (No data available)
readlink("foo", "bar", 4) = 3

I'd be curious to see what strace sees....

!!! · 05-26-2021, 05:22 PM

stat foo
(A quick and easy post)

+1 strace!!!

I love puzzles, but another clue needed.
Anything special about the distro or file system?
Ideally, give us a way to reproduce it.
Does this only happen in one particularly unique environment?

(I'm n00bCuruous why different from typical message:
[no /bin/], ls: [1st error from stat(2) returning ENOENT] cannot access [quoted]'filename':
No such ... [same ls msg])

Skaperen · 05-26-2021, 09:57 PM

Quote:

Originally Posted by cyent

Relevant part of strace ls -dl bar foo...

lstat("foo", {st_mode=S_IFLNK|0777, st_size=3, ...}) = 0
lgetxattr("foo", "security.selinux", 0x56520790d920, 255) = -1 ENODATA (No data available)
readlink("foo", "bar", 4) = 3

I'd be curious to see what strace sees....

that part is different:

Code:

lstat("foo", {st_mode=S_IFLNK|0777, st_size=3, ...}) = 0
lgetxattr("foo", "security.selinux", 0x564ae75e11c0, 255) = -1 ENOENT (No such file or directory)
write(2, "/bin/ls: ", 9/bin/ls: )                = 9
write(2, "foo", 3foo)                      = 3
write(2, ": No such file or directory", 27: No such file or directory) = 27
write(2, "\n", 1
)                       = 1
readlink("foo", "bar", 4)               = 3

looks like it gets an unexpected error from lgetxattr() and outputs that and goes on. it should either ignore it or do something different.

cyent · 05-26-2021, 11:06 PM

Hmmm... https://github.com/bazelbuild/sandboxfs/issues/100

Are you on an interesting and different filesystem?

cyent · 05-26-2021, 11:19 PM

Yup, ENOENT isn't coming from lstat() so file exists... so next most list is the listxattr handler on the VFS struct.... ie. You're using a file system that doesn't handle listxattr properly.

So the question is very much "which file system type is 'foo' on?"

rnturn · 05-28-2021, 10:38 AM

Quote:

Originally Posted by Skaperen

what is ls trying to tell me?

Code:

lt2a/sr /home2/sr 4> rm -fr bar foo
lt2a/sr /home2/sr 5> echo woot >bar
lt2a/sr /home2/sr 6> ln -s bar foo
lt2a/sr /home2/sr 7> ls -dl bar foo
/bin/ls: foo: No such file or directory
-rw-r--r-- 1 sr sr 5 May 25 18:03 bar

...

Just out of curiosity, does it work differently if you issue:

Code:

\ls -dl bar foo

???

Skaperen · 06-05-2021, 07:04 PM

Quote:

Originally Posted by cyent

Yup, ENOENT isn't coming from lstat() so file exists... so next most list is the listxattr handler on the VFS struct.... ie. You're using a file system that doesn't handle listxattr properly.

So the question is very much "which file system type is 'foo' on?"

it's an old encfs file system intended to encrypt part of an ext4 file system. encfs is lousy >encryption< but it solved a difficult situation long ago when i had just one drive. my next plan is to use real encryption on the whole 2nd drive when i move to Xubuntu 20.04 or maybe 22.04. no more encfs for me.