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Cygwin: FIFO: temporarily keep a conv_handle in syscalls.cc:open 

When a FIFO is opened, syscalls.cc:open always calls fstat on the
newly-created fhandler_fifo.  This results from a call to
device_access_denied.

To speed-up this fstat call, and therefore the open(2) call, use
PC_KEEP_HANDLE when the fhandler is created.  The resulting
conv_handle is retained until after the fstat call if the fhandler is
a FIFO; otherwise, it is closed immediately.
This commit is contained in:
Ken Brown 2021-02-09 12:11:02 -05:00
parent 70f6360869
commit 246121534a
1 changed files with 19 additions and 3 deletions
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22
winsup/cygwin/syscalls.cc
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@ -1487,8 +1487,15 @@ open (const char *unix_path, int flags, ...)
opt |= PC_CTTY;
}
/* If we're opening a FIFO, we will call device_access_denied
below. This leads to a call to fstat, which can use the
path_conv handle. */
opt |= PC_KEEP_HANDLE;
if (!(fh = build_fh_name (unix_path, opt, stat_suffixes)))
__leave; /* errno already set */
opt &= ~PC_KEEP_HANDLE;
if (!fh->isfifo ())
fh->pc.close_conv_handle ();
if ((flags & O_NOFOLLOW) && fh->issymlink () && !(flags & O_PATH))
{
set_errno (ELOOP);
@ -1555,9 +1562,18 @@ open (const char *unix_path, int flags, ...)
delete fh;
fh = fh_file;
}
else if ((fh->is_fs_special () && fh->device_access_denied (flags))
|| !fh->open_with_arch (flags, mode & 07777))
__leave; /* errno already set */
else
{
if (fh->is_fs_special ())
{
if (fh->device_access_denied (flags))
__leave; /* errno already set */
else if (fh->isfifo ())
fh->pc.close_conv_handle ();
}
if (!fh->open_with_arch (flags, mode & 07777))
__leave; /* errno already set */
}
/* Move O_TMPFILEs to the bin to avoid blocking the parent dir. */
if ((flags & O_TMPFILE) && !fh->pc.isremote ())
try_to_bin (fh->pc, fh->get_handle (), DELETE,