Added initial unfs3 sources for version 0.9.22+dfsg-1maemo2

[unfs3] / unfs3 / locate.c

diff --git a/unfs3/locate.c b/unfs3/locate.c
new file mode 100644 (file)
index 0000000..c5ed219
--- /dev/null
+++ b/unfs3/locate.c
@@ -0,0 +1,171 @@
+
+/*
+ * UNFS3 brute force file search
+ * (C) 2004, Pascal Schmidt
+ * see file LICENSE for license details
+ */
+
+#include "config.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <rpc/rpc.h>
+#include <dirent.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#if HAVE_MNTENT_H == 1
+#include <mntent.h>
+#endif
+
+#if HAVE_SYS_MNTTAB_H == 1
+#include <sys/mnttab.h>
+#endif
+
+#include "nfs.h"
+#include "fh.h"
+#include "daemon.h"
+
+/*
+ * these are the brute-force file searching routines that are used
+ * when both the filehandle cache and the hashed path inside the
+ * filehandle are unable to locate the file
+ *
+ * this can only happen if a file was rename(3)'d across directories
+ *
+ * these routines are slow, but better than returning ESTALE to
+ * clients
+ */
+
+#if HAVE_MNTENT_H == 1 || HAVE_SYS_MNTTAB_H == 1
+
+/*
+ * locate file given prefix, device, and inode number
+ */
+static int locate_pfx(const char *pfx, uint32 dev, uint64 ino, char *result)
+{
+    char path[NFS_MAXPATHLEN];
+    backend_dirstream *search;
+    struct dirent *ent;
+    struct stat buf;
+    int res;
+
+    search = opendir(pfx);
+    if (!search)
+       return FALSE;
+
+    while ((ent = readdir(search))) {
+       if (strlen(pfx) + strlen(ent->d_name) + 2 >= NFS_MAXPATHLEN)
+           continue;
+
+       sprintf(path, "%s/%s", pfx, ent->d_name);
+
+       res = lstat(path, &buf);
+       if (res != 0)
+           continue;
+
+       /* check for matching object */
+       if (buf.st_dev == dev && buf.st_ino == ino) {
+           strcpy(result, path);
+           st_cache = buf;
+           st_cache_valid = TRUE;
+           closedir(search);
+           return TRUE;
+       }
+
+       /* descend into directories with same dev */
+       if (buf.st_dev == dev && S_ISDIR(buf.st_mode) &&
+           strcmp(ent->d_name, ".") != 0 && strcmp(ent->d_name, "..") != 0) {
+           res = locate_pfx(path, dev, ino, result);
+           if (res == TRUE) {
+               closedir(search);
+               return TRUE;
+           }
+       }
+    }
+
+    closedir(search);
+    return FALSE;
+}
+#endif
+
+/*
+ * locate file given device and inode number
+ *
+ * slow fallback in case other filehandle resolution functions fail
+ */
+char *locate_file(U(uint32 dev), U(uint64 ino))
+{
+#if HAVE_MNTENT_H == 1 || HAVE_SYS_MNTTAB_H == 1
+    static char path[NFS_MAXPATHLEN];
+    FILE *mtab;
+    struct stat buf;
+    int res;
+#endif
+
+#if HAVE_MNTENT_H == 1
+    struct mntent *ent;
+#endif
+
+#if HAVE_SYS_MNTTAB_H == 1
+    struct mnttab ent;
+    int found = FALSE;
+#endif
+
+    if (!opt_brute_force)
+       return NULL;
+
+#if HAVE_MNTENT_H == 1
+    mtab = setmntent("/etc/mtab", "r");
+    if (!mtab)
+       return NULL;
+
+    /* 
+     * look for mtab entry with matching device
+     */
+    while ((ent = getmntent(mtab))) {
+       res = lstat(ent->mnt_dir, &buf);
+
+       if (res == 0 && buf.st_dev == dev)
+           break;
+    }
+    endmntent(mtab);
+
+    /* found matching entry? */
+    if (ent) {
+       res = locate_pfx(ent->mnt_dir, dev, ino, path);
+       if (res == TRUE)
+           return path;
+    }
+#endif
+
+#if HAVE_SYS_MNTTAB_H == 1
+    mtab = fopen("/etc/mnttab", "r");
+    if (!mtab)
+       return NULL;
+
+    /* 
+     * look for mnttab entry with matching device
+     */
+    while (getmntent(mtab, &ent) == 0) {
+       res = lstat(ent.mnt_mountp, &buf);
+
+       if (res == 0 && buf.st_dev == dev) {
+           found = TRUE;
+           break;
+       }
+    }
+    fclose(mtab);
+
+    /* found matching entry? */
+    if (found) {
+       res = locate_pfx(ent.mnt_mountp, dev, ino, path);
+       if (res == TRUE)
+           return path;
+    }
+#endif
+
+    return NULL;
+}