wimlib_mount(): Refuse to mount split wim read-write

[wimlib] / src / mount.c

diff --git a/src/mount.c b/src/mount.c
index e10287a6f58aa918aaa06852ba31b9a3ab1d5e25..4dc28f1fbc2c8fee36904530dff7c565b44c5d81 100644 (file)
--- a/src/mount.c
+++ b/src/mount.c
@@ -146,6 +146,9 @@ static int alloc_wimlib_fd(struct inode *inode,
 {
        static const u16 fds_per_alloc = 8;
        static const u16 max_fds = 0xffff;
+       int ret;
+
+       pthread_mutex_lock(&inode->i_mutex);
 
        DEBUG("Allocating fd for stream ID %u from inode %lx (open = %u, allocated = %u)",
              stream_id, inode->ino, inode->num_opened_fds,
@@ -155,16 +158,20 @@ static int alloc_wimlib_fd(struct inode *inode,
                struct wimlib_fd **fds;
                u16 num_new_fds;
 
-               if (inode->num_allocated_fds == max_fds)
-                       return -EMFILE;
+               if (inode->num_allocated_fds == max_fds) {
+                       ret = -EMFILE;
+                       goto out;
+               }
                num_new_fds = min(fds_per_alloc,
                                  max_fds - inode->num_allocated_fds);
 
                fds = REALLOC(inode->fds,
                              (inode->num_allocated_fds + num_new_fds) *
                                sizeof(inode->fds[0]));
-               if (!fds)
-                       return -ENOMEM;
+               if (!fds) {
+                       ret = -ENOMEM;
+                       goto out;
+               }
                memset(&fds[inode->num_allocated_fds], 0,
                       num_new_fds * sizeof(fds[0]));
                inode->fds = fds;
@@ -173,8 +180,10 @@ static int alloc_wimlib_fd(struct inode *inode,
        for (u16 i = 0; ; i++) {
                if (!inode->fds[i]) {
                        struct wimlib_fd *fd = CALLOC(1, sizeof(*fd));
-                       if (!fd)
-                               return -ENOMEM;
+                       if (!fd) {
+                               ret = -ENOMEM;
+                               break;
+                       }
                        fd->f_inode    = inode;
                        fd->f_lte      = lte;
                        fd->staging_fd = -1;
@@ -184,17 +193,24 @@ static int alloc_wimlib_fd(struct inode *inode,
                        inode->fds[i]  = fd;
                        inode->num_opened_fds++;
                        if (lte)
-                               lte->num_opened_fds++;
+                               atomic_inc(&lte->num_opened_fds);
                        DEBUG("Allocated fd (idx = %u)", fd->idx);
-                       return 0;
+                       ret = 0;
+                       break;
                }
        }
+out:
+       pthread_mutex_unlock(&inode->i_mutex);
+       return ret;
 }
 
 static void inode_put_fd(struct inode *inode, struct wimlib_fd *fd)
 {
        wimlib_assert(fd != NULL);
        wimlib_assert(inode != NULL);
+
+       pthread_mutex_lock(&inode->i_mutex);
+
        wimlib_assert(fd->f_inode == inode);
        wimlib_assert(inode->num_opened_fds != 0);
        wimlib_assert(fd->idx < inode->num_allocated_fds);
@@ -202,13 +218,17 @@ static void inode_put_fd(struct inode *inode, struct wimlib_fd *fd)
 
        inode->fds[fd->idx] = NULL;
        FREE(fd);
-       if (--inode->num_opened_fds == 0 && inode->link_count == 0)
+       if (--inode->num_opened_fds == 0 && inode->link_count == 0) {
+               pthread_mutex_unlock(&inode->i_mutex);
                free_inode(inode);
+       } else {
+               pthread_mutex_unlock(&inode->i_mutex);
+       }
 }
 
 static int lte_put_fd(struct lookup_table_entry *lte, struct wimlib_fd *fd)
 {
-       wimlib_assert(fd);
+       wimlib_assert(fd != NULL);
        wimlib_assert(fd->f_lte == lte);
 
        if (!lte) /* Empty stream with no lookup table entry */
@@ -232,7 +252,7 @@ static int lte_put_fd(struct lookup_table_entry *lte, struct wimlib_fd *fd)
 static int close_wimlib_fd(struct wimlib_fd *fd)
 {
        int ret;
-       wimlib_assert(fd);
+       wimlib_assert(fd != NULL);
        DEBUG("Closing fd (inode = %lu, opened = %u, allocated = %u)",
              fd->f_inode->ino, fd->f_inode->num_opened_fds,
              fd->f_inode->num_allocated_fds);
@@ -477,11 +497,9 @@ out_delete_staging_file:
 }
 
 /*
- * Creates a randomly named staging directory and returns its name into the
- * static variable staging_dir_name.
- *
- * If the staging directory cannot be created, staging_dir_name is set to NULL.
- * */
+ * Creates a randomly named staging directory and saves its name in the
+ * filesystem context structure.
+ */
 static int make_staging_dir(struct wimfs_context *ctx)
 {
        /* XXX Give the user an option of where to stage files */
@@ -856,7 +874,7 @@ static int rebuild_wim(struct wimfs_context *ctx, bool check_integrity)
 
 
        DEBUG("Closing all staging file descriptors.");
-       list_for_each_entry(lte, &ctx->staging_list, staging_list) {
+       list_for_each_entry_safe(lte, tmp, &ctx->staging_list, staging_list) {
                ret = inode_close_fds(lte->lte_inode);
                if (ret != 0)
                        return ret;
@@ -1836,6 +1854,11 @@ WIMLIBAPI int wimlib_mount(WIMStruct *wim, int image, const char *dir,
        if (ret != 0)
                return ret;
 
+       if ((flags & WIMLIB_MOUNT_FLAG_READWRITE) && (wim->hdr.total_parts != 1)) {
+               ERROR("Cannot mount a split WIM read-write");
+               return WIMLIB_ERR_SPLIT_UNSUPPORTED;
+       }
+
        if (num_additional_swms) {
                ret = new_joined_lookup_table(wim, additional_swms,
                                              num_additional_swms,
@@ -1893,7 +1916,10 @@ WIMLIBAPI int wimlib_mount(WIMStruct *wim, int image, const char *dir,
 
        argv[argc++] = "imagex";
        argv[argc++] = dir_copy;
-       argv[argc++] = "-s"; /* disable multi-threaded operation */
+
+       /* disable multi-threaded operation for read-write mounts */
+       if (flags & WIMLIB_MOUNT_FLAG_READWRITE)
+               argv[argc++] = "-s";
 
        if (flags & WIMLIB_MOUNT_FLAG_DEBUG)
                argv[argc++] = "-d";