[libvirt] [PATCH 03/16] LXC from native: migrate fstab and lxc.mount.entry

Cédric Bosdonnat cbosdonnat at suse.com
Tue Jan 14 13:49:52 UTC 2014


Tmpfs default usage is computed based on the host physical memory. To
test this more easily, the value is computed outside the parse method.
---
 src/lxc/lxc_container.c                      |   2 +-
 src/lxc/lxc_container.h                      |   2 +
 src/lxc/lxc_native.c                         | 295 ++++++++++++++++++++++++++-
 tests/lxcconf2xmldata/lxcconf2xml-simple.xml |   9 +
 4 files changed, 302 insertions(+), 6 deletions(-)

diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c
index c6bdc8c..f08dbc2 100644
--- a/src/lxc/lxc_container.c
+++ b/src/lxc/lxc_container.c
@@ -744,7 +744,7 @@ static const virLXCBasicMountInfo lxcBasicMounts[] = {
 };
 
 
-static bool lxcIsBasicMountLocation(const char *path)
+bool lxcIsBasicMountLocation(const char *path)
 {
     size_t i;
 
diff --git a/src/lxc/lxc_container.h b/src/lxc/lxc_container.h
index e74a7d7..67292ab 100644
--- a/src/lxc/lxc_container.h
+++ b/src/lxc/lxc_container.h
@@ -71,4 +71,6 @@ virArch lxcContainerGetAlt32bitArch(virArch arch);
 
 int lxcContainerChown(virDomainDefPtr def, const char *path);
 
+bool lxcIsBasicMountLocation(const char *path);
+
 #endif /* LXC_CONTAINER_H */
diff --git a/src/lxc/lxc_native.c b/src/lxc/lxc_native.c
index 2cd9143..9e2e870 100644
--- a/src/lxc/lxc_native.c
+++ b/src/lxc/lxc_native.c
@@ -21,11 +21,14 @@
  */
 
 #include <config.h>
+#include <stdio.h>
 #include <sys/stat.h>
 
 #include "internal.h"
+#include "lxc_container.h"
 #include "lxc_native.h"
 #include "util/viralloc.h"
+#include "util/virfile.h"
 #include "util/virlog.h"
 #include "util/virstring.h"
 
@@ -206,7 +209,11 @@ lxcParseProperties(const char *properties)
 }
 
 static virDomainFSDefPtr
-lxcCreateFSDef(int type, char *src, char* dst)
+lxcCreateFSDef(int type,
+               char *src,
+               char* dst,
+               bool readonly,
+               unsigned long long usage)
 {
     virDomainFSDefPtr def;
 
@@ -217,16 +224,181 @@ lxcCreateFSDef(int type, char *src, char* dst)
     def->accessmode = VIR_DOMAIN_FS_ACCESSMODE_PASSTHROUGH;
     def->src = src;
     def->dst = dst;
+    def->readonly = readonly;
+    def->usage = usage;
 
     return def;
 }
 
+typedef struct _lxcFstab lxcFstab;
+typedef lxcFstab *lxcFstabPtr;
+struct _lxcFstab {
+    lxcFstabPtr next;
+    char *src;
+    char *dst;
+    char *type;
+    char *options;
+};
+
+static void
+lxcFstabFree(lxcFstabPtr fstab)
+{
+    while (fstab) {
+        lxcFstabPtr next = NULL;
+        next = fstab->next;
+
+        VIR_FREE(fstab->src);
+        VIR_FREE(fstab->dst);
+        VIR_FREE(fstab->type);
+        VIR_FREE(fstab->options);
+        VIR_FREE(fstab);
+
+        fstab = next;
+    }
+}
+
+static char ** lxcStringSplit(const char *string)
+{
+    char *tmp;
+    size_t i;
+    size_t ntokens = 0;
+    char **parts;
+    char **result = NULL;
+
+    if (VIR_STRDUP(tmp, string) < 0)
+        return NULL;
+
+    /* Replace potential \t by a space */
+    for (i = 0; tmp[i]; i++) {
+        if (tmp[i] == '\t')
+            tmp[i] = ' ';
+    }
+
+    parts = virStringSplit(tmp, " ", 0);
+    for (i = 0; parts[i]; i++) {
+        if (STREQ(parts[i], ""))
+            continue;
+
+        if (VIR_EXPAND_N(result, ntokens, 1) < 0)
+            goto error;
+
+        if (VIR_STRDUP(result[ntokens-1], parts[i]) < 0)
+            goto error;
+    }
+
+    /* Append NULL element */
+    if (VIR_EXPAND_N(result, ntokens, 1) < 0)
+        goto error;
+
+    VIR_FREE(tmp);
+    virStringFreeList(parts);
+    return result;
+
+error:
+    VIR_FREE(tmp);
+    virStringFreeList(parts);
+    virStringFreeList(result);
+    return NULL;
+}
+
+static lxcFstabPtr
+lxcParseFstabLine(char *fstabLine)
+{
+    lxcFstabPtr fstab = NULL;
+    char **parts;
+
+    if (VIR_ALLOC(fstab) < 0)
+        return NULL;
+
+    parts = lxcStringSplit(fstabLine);
+
+    if (!parts[0] || !parts[1] || !parts[2] || !parts[3])
+        goto error;
+
+    if (VIR_STRDUP(fstab->src, parts[0]) < 0 ||
+            VIR_STRDUP(fstab->dst, parts[1]) < 0 ||
+            VIR_STRDUP(fstab->type, parts[2]) < 0 ||
+            VIR_STRDUP(fstab->options, parts[3]) < 0)
+        goto error;
+
+    virStringFreeList(parts);
+
+    return fstab;
+
+error:
+    lxcFstabFree(fstab);
+    virStringFreeList(parts);
+    return NULL;
+}
+
+static lxcFstabPtr
+lxcParseFstabString(const char *fstabString)
+{
+    lxcFstabPtr fstab = NULL;
+    char **lines;
+    size_t i;
+    lxcFstabPtr line = NULL;
+
+    lines = virStringSplit(fstabString, "\n", 0);
+
+    for (i = 0; lines[i]; i++) {
+        if (!(line = lxcParseFstabLine(lines[i])))
+            continue;
+        line->next = fstab;
+        fstab = line;
+    }
+
+    virStringFreeList(lines);
+
+    return fstab;
+}
+
+static lxcFstabPtr
+lxcParseFstabFile(const char *path)
+{
+    lxcFstabPtr fstab = NULL;
+    FILE *fp = fopen(path, "r");
+    char *tmp;
+    int tmplen = 0;
+    lxcFstabPtr line = NULL;
+
+    if (!fp) {
+        char errbuf[1024];
+        VIR_ERROR(_("Failed to open file %s: %s"), path,
+                  virStrerror(errno, errbuf, sizeof(errbuf)));
+        goto cleanup;
+    }
+
+    while (fgets(tmp, tmplen, fp) != NULL) {
+        if (tmplen == 0 || !(line = lxcParseFstabLine(tmp)))
+            continue;
+        line->next = fstab;
+        fstab = line;
+    }
+
+    if (ferror(fp)) {
+        char errbuf[1024];
+        VIR_ERROR(_("Failed to read file %s: %s"), path,
+                  virStrerror(errno, errbuf, sizeof(errbuf)));
+    }
+
+cleanup:
+    VIR_FORCE_FCLOSE(fp);
+
+    return fstab;
+}
+
 static int
-lxcAddFSDef(virDomainDefPtr def, int type, char *src, char *dst)
+lxcAddFSDef(virDomainDefPtr def,
+            int type,
+            char *src,
+            char *dst,
+            bool readonly,
+            unsigned long long usage)
 {
     virDomainFSDefPtr fsDef = NULL;
 
-    if (!(fsDef = lxcCreateFSDef(type, src, dst)))
+    if (!(fsDef = lxcCreateFSDef(type, src, dst, readonly, usage)))
         goto error;
 
     if (VIR_EXPAND_N(def->fss, def->nfss, 1) < 0)
@@ -260,7 +432,7 @@ lxcSetRootfs(virDomainDefPtr def,
         type = VIR_DOMAIN_FS_TYPE_BLOCK;
 
 
-    if (lxcAddFSDef(def, type, fssrc, fsdst) < 0)
+    if (lxcAddFSDef(def, type, fssrc, fsdst, false, 0) < 0)
         goto error;
 
     return 0;
@@ -271,13 +443,90 @@ error:
     return -1;
 }
 
+static unsigned long long
+lxcConvertSize(const char *size, unsigned long memory)
+{
+    unsigned long long value = 0;
+    char *unit = NULL;
+
+    /* Split the string into value and unit */
+    if (virStrToLong_ull(size, &unit, 10, &value) < 0)
+        return 0;
+
+    if (STREQ(unit, "%")) {
+        value = value * memory * 1024 / 100;
+
+    } else if (virScaleInteger(&value, unit, 1, ULLONG_MAX) < 0)
+        return 0;
+
+    return value;
+}
+
+static int
+lxcAddFstabLine(virDomainDefPtr def, lxcFstabPtr fstab, unsigned long memory)
+{
+    char *src = NULL;
+    char *dst = NULL;
+    char **options = virStringSplit(fstab->options, ",", 0);
+    bool readonly;
+    int type = VIR_DOMAIN_FS_TYPE_MOUNT;
+    unsigned long long usage = 0;
+
+    if (fstab->dst[0] != '/') {
+        if (virAsprintf(&dst, "/%s", fstab->dst) < 0)
+            goto error;
+    } else if (VIR_STRDUP(dst, fstab->dst) < 0)
+        goto error;
+
+    /* Check that we don't add basic mounts */
+    if (lxcIsBasicMountLocation(dst)) {
+        VIR_FREE(dst);
+        return 0;
+    }
+
+    if (STREQ(fstab->type, "tmpfs")) {
+        char *sizeStr = NULL;
+        size_t i;
+        type = VIR_DOMAIN_FS_TYPE_RAM;
+
+        for (i = 0; options[i]; i++) {
+            if ((sizeStr = STRSKIP(options[i], "size="))) {
+                usage = lxcConvertSize(sizeStr, memory);
+                break;
+            }
+        }
+        /* Default tmpfs size is 50%, cf kernel doc */
+        if (!sizeStr)
+            usage = lxcConvertSize("50%", memory);
+    } else if (VIR_STRDUP(src, fstab->src) < 0)
+        goto error;
+
+    /* Do we have ro in options? */
+    readonly = virStringArrayHasString(options, "ro");
+
+    if (lxcAddFSDef(def, type, src, dst, readonly, usage) < 0)
+        goto error;
+
+
+    return 1;
+
+error:
+    VIR_FREE(dst);
+    VIR_FREE(src);
+    virStringFreeList(options);
+    return -1;
+}
+
 virDomainDefPtr
 lxcParseConfigString(const char *config,
-                     const char *fstab ATTRIBUTE_UNUSED,
+                     const char *fstab,
                      unsigned long memory)
 {
     virDomainDefPtr vmdef = NULL;
     virPropertiesPtr properties = NULL;
+    lxcFstabPtr fstabEntries = NULL;
+    char *mountLine = NULL;
+    lxcFstabPtr fstabIter = NULL;
 
     if (!(properties = lxcParseProperties(config)))
         return NULL;
@@ -290,6 +539,7 @@ lxcParseConfigString(const char *config,
                        _("failed to generate uuid"));
         goto error;
     }
+
     vmdef->id = -1;
     vmdef->mem.max_balloon = memory;
 
@@ -302,6 +552,8 @@ lxcParseConfigString(const char *config,
      * minimum required to make XML parsing pass */
     vmdef->maxvcpus = 1;
 
+    vmdef->nfss = 0;
+
     if (VIR_STRDUP(vmdef->os.type, "exe") < 0)
         goto error;
 
@@ -316,6 +568,38 @@ lxcParseConfigString(const char *config,
     if (lxcSetRootfs(vmdef, properties) < 0)
         goto error;
 
+    /* Look for fstab */
+    if (!fstab) {
+        char *fstabPath = NULL;
+        if (VIR_STRDUP(fstabPath, virPropertiesLookup(properties, "lxc.mount")) < 0)
+            goto error;
+
+        fstabEntries = lxcParseFstabFile(fstabPath);
+        VIR_FREE(fstabPath);
+    } else {
+        fstabEntries = lxcParseFstabString(fstab);
+    }
+
+    /* Loop over lxc.mount.entry to add them to fstab */
+    mountLine = virPropertiesLookup(properties, "lxc.mount.entry");
+    while (mountLine) {
+        lxcFstabPtr fstabLine = lxcParseFstabLine(mountLine);
+        if (fstabLine) {
+            fstabLine->next = fstabEntries;
+            fstabEntries = fstabLine;
+        }
+        mountLine = virPropertiesLookup(properties, NULL);
+    }
+
+    /* Loop over fstab entries to add filesystem devices for them */
+    fstabIter = fstabEntries;
+    while (fstabIter) {
+        if (lxcAddFstabLine(vmdef, fstabIter, memory) < 0)
+            goto error;
+
+        fstabIter = fstabIter->next;
+    }
+
     goto cleanup;
 
 error:
@@ -323,6 +607,7 @@ error:
     vmdef = NULL;
 
 cleanup:
+    lxcFstabFree(fstabEntries);
     virPropertiesFree(properties);
 
     return vmdef;
diff --git a/tests/lxcconf2xmldata/lxcconf2xml-simple.xml b/tests/lxcconf2xmldata/lxcconf2xml-simple.xml
index 621e699..8f2d442 100644
--- a/tests/lxcconf2xmldata/lxcconf2xml-simple.xml
+++ b/tests/lxcconf2xmldata/lxcconf2xml-simple.xml
@@ -17,5 +17,14 @@
       <source dir='/var/lib/lxc/migrate_test/rootfs'/>
       <target dir='/'/>
     </filesystem>
+    <filesystem type='mount' accessmode='passthrough'>
+      <source dir='/etc/resolv.conf'/>
+      <target dir='/etc/resolv.conf'/>
+      <readonly/>
+    </filesystem>
+    <filesystem type='ram' accessmode='passthrough'>
+      <source usage='2017885' units='KiB'/>
+      <target dir='/run'/>
+    </filesystem>
   </devices>
 </domain>
-- 
1.8.5.2




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