Attachment 603058 Details for Bug 846751 – git patch against gnome-keyring 3.4.1.

[patch] git patch against gnome-keyring 3.4.1.

Provide-fallback-for-file-systems-without-working-ha.patch (text/plain), 8.16 KB, created by Werner Koch on 2012-08-08 15:29:52 UTC

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Creator: Werner Koch

Created: 2012-08-08 15:29:52 UTC

Size: 8.16 KB

patch

obsolete

>From 6c06cab7d9df5b98211a947614152c3444a512a5 Mon Sep 17 00:00:00 2001
>From: Werner Koch <wk@gnupg.org>
>Date: Wed, 1 Aug 2012 17:23:19 +0200
>Subject: [PATCH] Provide fallback for file systems without working hardlinks
>
>* pkcs11/gkm/gkm-transaction.c (O_BINARY): Add fallback for Windows.
>(copy_to_temp_file): New.
>(begin_link_temporary_if_exists): Detect failure link(2) and resort to
>a copy file method.
>--
>
>See bug 657234 for a description of the problem.  The culprit is the
>CIFS implementation on EMC servers.  At least VFAT file systems should
>have the same problem, thus the patch is a general improvement.
>---
> pkcs11/gkm/gkm-transaction.c |  156 ++++++++++++++++++++++++++++++++++++++----
> 1 files changed, 143 insertions(+), 13 deletions(-)
>
>diff --git a/pkcs11/gkm/gkm-transaction.c b/pkcs11/gkm/gkm-transaction.c
>index a15f810..9c7f287 100644
>--- a/pkcs11/gkm/gkm-transaction.c
>+++ b/pkcs11/gkm/gkm-transaction.c
>@@ -31,6 +31,10 @@
> #include <string.h>
> #include <unistd.h>
> 
>+#ifndef O_BINARY
>+# define O_BINARY 0
>+#endif
>+
> enum {
> 	PROP_0,
> 	PROP_COMPLETED,
>@@ -168,10 +172,96 @@ complete_link_temporary (GkmTransaction *self, GObject *unused, gpointer user_da
> 	return ret;
> }
> 
>+
>+/* Copy the file SRCNAME to the file DSTNAME.  If DSTNAME already
>+   exists -1 is returned and ERRNO set to EEXIST.  Returns 0 on
>+   success. */
>+static int
>+copy_to_temp_file (const char *dstname, const char *srcname)
>+{
>+        int dstfd, srcfd;
>+        int nread, nwritten;
>+        int saveerr;
>+        char *bufp;
>+        char buffer[512]; /* If you change this size, please also adjust */
>+                          /* test-transaction.c:test_write_large_file.   */
>+
>+        do {
>+                srcfd = g_open (srcname, (O_RDONLY | O_BINARY));
>+        } while (srcfd == -1 && errno == EINTR);
>+        if (srcfd == -1) {
>+                saveerr = errno;
>+                g_warning ("couldn't open file to "
>+                           "take temporary copy from: %s: %s",
>+                           srcname, g_strerror (saveerr));
>+                errno = saveerr;
>+                return -1;
>+        }
>+
>+        do {
>+                dstfd = g_open (dstname,
>+                                (O_WRONLY | O_CREAT | O_EXCL | O_BINARY),
>+                                (S_IRUSR | S_IWUSR));
>+        } while (dstfd == -1 && errno == EINTR);
>+        if (dstfd == -1) {
>+                saveerr = errno;
>+                close (srcfd);
>+                errno = saveerr;
>+                return -1;
>+        }
>+
>+        while ((nread = read (srcfd, buffer, sizeof buffer))) {
>+                if (nread == -1 && errno == EINTR)
>+                        continue;
>+                if (nread == -1) {
>+                        saveerr = errno;
>+                        g_warning ("error reading file to "
>+                                   "take temporary copy from: %s: %s",
>+                                   srcname, g_strerror (saveerr));
>+                        goto failure;
>+                }
>+
>+                bufp = buffer;
>+                do {
>+                        do {
>+                                nwritten = write (dstfd, bufp, nread);
>+                        } while (nwritten == -1 && errno == EINTR);
>+                        if (nwritten == -1) {
>+                                saveerr = errno;
>+                                g_warning ("error wrinting to "
>+                                           "temporary file: %s: %s",
>+                                           dstname, g_strerror (saveerr));
>+                                goto failure;
>+                        }
>+                        g_assert (nwritten <= nread);
>+                        nread -= nwritten;
>+                        bufp += nwritten;
>+                } while (nread > 0);
>+        }
>+        /* EOF reached.  */
>+        if (close (dstfd)) {
>+                saveerr = errno;
>+                g_warning ("error closing temporary file: %s: %s",
>+                           dstname, g_strerror (saveerr));
>+                goto failure;
>+        }
>+        close (srcfd);
>+        return 0;
>+
>+failure:
>+        close (dstfd);  /* (Doesn't harm if we try a second time.) */
>+        if (g_unlink (dstname))
>+                g_warning ("couldn't remove temporary file: %s: %s",
>+                           dstname, g_strerror (saveerr));
>+        close (srcfd);
>+        errno = saveerr;
>+        return -1;
>+}
>+
>+
> static gboolean
> begin_link_temporary_if_exists (GkmTransaction *self, const gchar *filename, gboolean *exists)
> {
>-	gchar *result;
> 	guint i = 0;
> 
> 	g_assert (GKM_IS_TRANSACTION (self));
>@@ -180,27 +270,67 @@ begin_link_temporary_if_exists (GkmTransaction *self, const gchar *filename, gbo
> 	g_assert (exists);
> 
> 	for (i = 0; i < MAX_TRIES; ++i) {
>+                struct stat sb;
>+                unsigned int nlink;
>+                int stat_failed = 0;
> 
> 		*exists = TRUE;
> 
>-		/* Try to link to random temporary file names */
>-		result = g_strdup_printf ("%s.temp-%d", filename, g_random_int_range (0, G_MAXINT));
>-		if (link (filename, result) == 0) {
>-			gkm_transaction_add (self, NULL, complete_link_temporary, result);
>-			return TRUE;
>-		}
>-
>-		g_free (result);
>-
>-		/* The original file does not exist */
>-		if (errno == ENOENT || errno == ENOTDIR) {
>+		/* Try to link to random temporary file names.  We try
>+                 * to use a hardlink to create a copy but if that
>+                 * fails (i.e. not supported by the FS), we copy the
>+                 * entire file.  The result should be the same except
>+                 * that the file times will change if we need to
>+                 * rollback the transaction. */
>+                if (stat (filename, &sb)) {
>+                        stat_failed = 1;
>+                } else {
>+                        gchar *result;
>+
>+                        result = g_strdup_printf
>+                                ("%s.temp-%d", filename,
>+                                 g_random_int_range (0, G_MAXINT));
>+                        nlink = (unsigned int)sb.st_nlink;
>+                        /* The result code of link(2) is not reliable.
>+                         * Unless it fails with EEXIST we stat the
>+                         * file to check for success.  Note that there
>+                         * is a race here: If another process adds a
>+                         * link to the source file between link and
>+                         * stat, the check on the increased link count
>+                         * will fail.  Fortunately the case for
>+                         * hardlinks are not working solves it.  */
>+                        if (link (filename, result) && errno == EEXIST) {
>+                                /* This is probably a valid error.
>+                                 * Let us try another temporary file.  */
>+                        } else if (stat (filename, &sb)) {
>+                                stat_failed = 1;
>+                        } else {
>+                                if ((sb.st_nlink == nlink + 1)
>+                                    || !copy_to_temp_file (result,
>+                                                           filename)) {
>+                                        /* Either the link worked or
>+                                         * the copy succeeded.  */
>+                                        gkm_transaction_add
>+                                                (self, NULL,
>+                                                 complete_link_temporary,
>+                                                 result);
>+                                        return TRUE;
>+                                }
>+                        }
>+
>+                        g_free (result);
>+                }
>+
>+                if (stat_failed && (errno == ENOENT || errno == ENOTDIR)) {
>+                        /* The original file does not exist */
> 			*exists = FALSE;
> 			return TRUE;
> 		}
> 
> 		/* If exists, try again, otherwise fail */
> 		if (errno != EEXIST) {
>-			g_warning ("couldn't create temporary file for: %s: %s", filename, g_strerror (errno));
>+			g_warning ("couldn't create temporary file "
>+                                   "for: %s: %s", filename, g_strerror (errno));
> 			gkm_transaction_fail (self, CKR_DEVICE_ERROR);
> 			return FALSE;
> 		}
>-- 
>1.7.7.1
>

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Attachments on bug 846751: 603058