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TAR VFS: dereference hard links when opening files

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Fixes #1636
Issue #1653
This commit is contained in:
Emery Hemingway 2015-07-24 09:15:34 -05:00 committed by Christian Helmuth
parent 8c168d7943
commit 4a5b7be4e7
1 changed files with 35 additions and 55 deletions
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90
repos/os/include/vfs/tar_file_system.h
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@ -348,6 +348,22 @@ class Vfs::Tar_file_system : public File_system
}
} _cached_num_dirent;
/**
* Walk hardlinks until we reach a file
*
* XXX: check for hardlink loops
*/
Node const *dereference(char const *path)
{
Node const *node = _root_node.lookup(path);
if (!node) return 0;
Record const *record = node->record;
if (!record || record->type() != Record::TYPE_HARDLINK)
return node;
return dereference(record->linked_name());
}
public:
@ -373,34 +389,14 @@ class Vfs::Tar_file_system : public File_system
Dataspace_capability dataspace(char const *path) override
{
/*
* Walk hardlinks until we reach a file
*/
Record const *record = 0;
for (;;) {
Node *node = _root_node.lookup(path);
if (!node)
return Dataspace_capability();
record = node->record;
if (record) {
if (record->type() == Record::TYPE_HARDLINK) {
path = record->linked_name();
continue;
}
if (record->type() == Record::TYPE_FILE)
break;
PERR("TAR record \"%s\" has unsupported type %d",
record->name(), record->type());
}
Node const *node = dereference(path);
if (!node || !node->record)
return Dataspace_capability();
Record const *record = node->record;
if (record->type() != Record::TYPE_FILE) {
PERR("TAR record \"%s\" has unsupported type %d",
path, Record::TYPE_DIR);
path, record->type());
return Dataspace_capability();
}
@ -429,36 +425,21 @@ class Vfs::Tar_file_system : public File_system
if (verbose)
PDBG("path = %s", path);
Node const *node = 0;
Record const *record = 0;
Node const *node = dereference(path);
if (!node)
return STAT_ERR_NO_ENTRY;
/*
* Walk hardlinks until we reach a file
*/
for (;;) {
node = _root_node.lookup(path);
if (!node->record) {
if (verbose)
PDBG("found a virtual directoty node");
if (!node)
return STAT_ERR_NO_ENTRY;
record = node->record;
if (record) {
if (record->type() == Record::TYPE_HARDLINK) {
path = record->linked_name();
continue;
} else
break;
} else {
if (verbose)
PDBG("found a virtual directoty node");
memset(&out, 0, sizeof(out));
out.mode = STAT_MODE_DIRECTORY;
return STAT_OK;
}
memset(&out, 0, sizeof(out));
out.mode = STAT_MODE_DIRECTORY;
return STAT_OK;
}
Record const *record = node->record;
/* convert TAR record modes to stat modes */
unsigned mode = record->mode();
switch (record->type()) {
@ -581,9 +562,8 @@ class Vfs::Tar_file_system : public File_system
Open_result open(char const *path, unsigned, Vfs_handle **out_handle) override
{
Node *node = _root_node.lookup(path);
if (!node)
Node const *node = dereference(path);
if (!node || !node->record || node->record->type() != Record::TYPE_FILE)
return OPEN_ERR_UNACCESSIBLE;
*out_handle = new (env()->heap())