• Peter Staubach's avatar
    [PATCH] open returns ENFILE but creates file anyway · a1a5b3d9
    Peter Staubach authored
    When open(O_CREAT) is called and the error, ENFILE, is returned, the file
    may be created anyway.  This is counter intuitive, against the SUS V3
    specification, and may cause applications to misbehave if they are not
    coded correctly to handle this semantic.  The SUS V3 specification
    explicitly states "No files shall be created or modified if the function
    returns -1.".
    The error, ENFILE, is used to indicate the system wide open file table is
    full and no more file structs can be allocated.
    This is due to an ordering problem.  The entry in the directory is created
    before the file struct is allocated.  If the allocation for the file struct
    fails, then the system call must return an error, but the directory entry
    was already created and can not be safely removed.
    The solution to this situation is relatively easy.  The file struct should
    be allocated before the directory entry is created.  If the allocation
    fails, then the error can be returned directly.  If the creation of the
    directory entry fails, then the file struct can be easily freed.
    Signed-off-by: default avatarPeter Staubach <staubach@redhat.com>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
open.c 23.6 KB