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Fix handling of linked rename chains in incremental backups

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* src/incremen.c: Change the meaning of the DIRF_RENAMED flag.  Now it
marks a directory which is the last one in a chain of renames.
Regular renamed directories are recognized by their orig member being
non-NULL.  Directories marked with DIRF_RENAMED start encoding of renames.
(procdir): Clear DIRF_RENAMED flag on directories which are origins for
renames.
(makedumpdir): Use the orig member to check if the directory is a
result of a rename.
(store_rename): Move the check for DIR_IS_RENAMED to the caller. Don't
clear the DIRF_RENAMED, it is not needed any more.

* tests/rename06.at: New test.
* tests/Makefile.am: Add rename06.at
* tests/testsuite.at: Likewise.
This commit is contained in:
Sergey Poznyakoff
2020-02-15 10:57:35 +02:00
parent 8d90723d30
commit 41654f91f0
4 changed files with 133 additions and 40 deletions
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83
src/incremen.c
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@@ -38,7 +38,15 @@ enum children
#define DIRF_FOUND 0x0004 /* directory is found on fs */
#define DIRF_NEW 0x0008 /* directory is new (not found
in the previous dump) */
#define DIRF_RENAMED 0x0010 /* directory is renamed */
#define DIRF_RENAMED 0x0010 /* Last target in a chain of renames */
/* A directory which is renamed from another one is recognized by its
orig member, which is not-NULL. This directory may eventually be
the source for another rename, in which case it will be pointed to by
the orig member of another directory structure. The last directory
in such a chain of renames (the one which is not pointed to by any
other orig) is marked with the DIRF_RENAMED flag. This marks a starting
point from which append_incremental_renames starts encoding renames for
this chain. */
#define DIR_IS_INITED(d) ((d)->flags & DIRF_INIT)
#define DIR_IS_NFS(d) ((d)->flags & DIRF_NFS)
@@ -495,6 +503,7 @@ procdir (const char *name_buffer, struct tar_stat_info *st,
quote_n (1, d->name)));
directory->orig = d;
DIR_SET_FLAG (directory, DIRF_RENAMED);
DIR_CLEAR_FLAG (d, DIRF_RENAMED);
dirlist_replace_prefix (d->name, name_buffer);
}
directory->children = CHANGED_CHILDREN;
@@ -537,6 +546,7 @@ procdir (const char *name_buffer, struct tar_stat_info *st,
quote_n (1, d->name)));
directory->orig = d;
DIR_SET_FLAG (directory, DIRF_RENAMED);
DIR_CLEAR_FLAG (d, DIRF_RENAMED);
dirlist_replace_prefix (d->name, name_buffer);
}
directory->children = CHANGED_CHILDREN;
@@ -649,7 +659,7 @@ makedumpdir (struct directory *directory, const char *dir)
if (directory->children == ALL_CHILDREN)
dump = NULL;
else if (DIR_IS_RENAMED (directory))
else if (directory->orig)
dump = directory->orig->idump ?
directory->orig->idump : directory->orig->dump;
else
@@ -878,44 +888,36 @@ obstack_code_rename (struct obstack *stk, char const *from, char const *to)
static void
store_rename (struct directory *dir, struct obstack *stk)
{
if (DIR_IS_RENAMED (dir))
struct directory *prev, *p;
/* Detect eventual cycles. If the chain forms a cycle, prev points to
the entry DIR is renamed from.*/
for (prev = dir; prev && prev->orig != dir; prev = prev->orig)
;
if (prev == NULL)
{
struct directory *prev, *p;
/* Detect eventual cycles and clear DIRF_RENAMED flag, so these entries
are ignored when hit by this function next time.
If the chain forms a cycle, prev points to the entry DIR is renamed
from. In this case it still retains DIRF_RENAMED flag, which will be
cleared in the 'else' branch below */
for (prev = dir; prev && prev->orig != dir; prev = prev->orig)
DIR_CLEAR_FLAG (prev, DIRF_RENAMED);
if (prev == NULL)
{
for (p = dir; p && p->orig; p = p->orig)
obstack_code_rename (stk, p->orig->name, p->name);
}
else
{
char *temp_name;
DIR_CLEAR_FLAG (prev, DIRF_RENAMED);
/* Break the cycle by using a temporary name for one of its
elements.
First, create a temp name stub entry. */
temp_name = dir_name (dir->name);
obstack_1grow (stk, 'X');
obstack_grow (stk, temp_name, strlen (temp_name) + 1);
obstack_code_rename (stk, dir->name, "");
for (p = dir; p != prev; p = p->orig)
obstack_code_rename (stk, p->orig->name, p->name);
obstack_code_rename (stk, "", prev->name);
free (temp_name);
}
for (p = dir; p && p->orig; p = p->orig)
obstack_code_rename (stk, p->orig->name, p->name);
}
else
{
char *temp_name;
/* Break the cycle by using a temporary name for one of its
elements.
First, create a temp name stub entry. */
temp_name = dir_name (dir->name);
obstack_1grow (stk, 'X');
obstack_grow (stk, temp_name, strlen (temp_name) + 1);
obstack_code_rename (stk, dir->name, "");
for (p = dir; p != prev; p = p->orig)
obstack_code_rename (stk, p->orig->name, p->name);
obstack_code_rename (stk, "", prev->name);
free (temp_name);
}
}
@@ -941,7 +943,8 @@ append_incremental_renames (struct directory *dir)
size = 0;
for (dp = dirhead; dp; dp = dp->next)
store_rename (dp, &stk);
if (DIR_IS_RENAMED (dp))
store_rename (dp, &stk);
/* FIXME: Is this the right thing to do when DIR is null? */
if (dir && obstack_object_size (&stk) != size)