rdelaage
/
postgresql
mirror of https://git.postgresql.org/git/postgresql.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Fix multiple bugs in tablespace symlink removal. 

Don't try to examine S_ISLNK(st.st_mode) after a failed lstat().
It's undefined.

Also, if the lstat() reported ENOENT, we do not wish that to be a hard
error, but the code might nonetheless treat it as one (giving an entirely
misleading error message, too) depending on luck-of-the-draw as to what
S_ISLNK() returned.

Don't throw error for ENOENT from rmdir(), either.  (We're not really
expecting ENOENT because we just stat'd the file successfully; but
if we're going to allow ENOENT in the symlink code path, surely the
directory code path should too.)

Generate an appropriate errcode for its-the-wrong-type-of-file complaints.
(ERRCODE_SYSTEM_ERROR doesn't seem appropriate, and failing to write
errcode() around it certainly doesn't work, and not writing an errcode
at all is not per project policy.)

Valgrind noticed the undefined S_ISLNK result; the other problems emerged
while reading the code in the area.

All of this appears to have been introduced in 8f15f74a44.
Back-patch to 9.5 where that commit appeared.
This commit is contained in:
Tom Lane 2016-04-08 12:31:42 -04:00
parent 752b948dfc
commit 93c301fc4f
1 changed files with 23 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
src/backend/commands/tablespace.c
View File

@ -773,13 +773,26 @@ destroy_tablespace_directories(Oid tablespaceoid, bool redo)
remove_symlink:
linkloc = pstrdup(linkloc_with_version_dir);
get_parent_directory(linkloc);
if (lstat(linkloc, &st) == 0 && S_ISDIR(st.st_mode))
if (lstat(linkloc, &st) < 0)
{
int saved_errno = errno;
ereport(redo ? LOG : (saved_errno == ENOENT ? WARNING : ERROR),
(errcode_for_file_access(),
errmsg("could not stat file \"%s\": %m",
linkloc)));
}
else if (S_ISDIR(st.st_mode))
{
if (rmdir(linkloc) < 0)
ereport(redo ? LOG : ERROR,
{
int saved_errno = errno;
ereport(redo ? LOG : (saved_errno == ENOENT ? WARNING : ERROR),
(errcode_for_file_access(),
errmsg("could not remove directory \"%s\": %m",
linkloc)));
}
}
#ifdef S_ISLNK
else if (S_ISLNK(st.st_mode))
@ -799,7 +812,7 @@ remove_symlink:
{
/* Refuse to remove anything that's not a directory or symlink */
ereport(redo ? LOG : ERROR,
(ERRCODE_SYSTEM_ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("\"%s\" is not a directory or symbolic link",
linkloc)));
}
@ -851,7 +864,7 @@ remove_tablespace_symlink(const char *linkloc)
{
struct stat st;
if (lstat(linkloc, &st) != 0)
if (lstat(linkloc, &st) < 0)
{
if (errno == ENOENT)
return;
@ -863,10 +876,10 @@ remove_tablespace_symlink(const char *linkloc)
if (S_ISDIR(st.st_mode))
{
/*
* This will fail if the directory isn't empty, but not
* if it's a junction point.
* This will fail if the directory isn't empty, but not if it's a
* junction point.
*/
if (rmdir(linkloc) < 0)
if (rmdir(linkloc) < 0 && errno != ENOENT)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not remove directory \"%s\": %m",
@ -878,7 +891,7 @@ remove_tablespace_symlink(const char *linkloc)
if (unlink(linkloc) < 0 && errno != ENOENT)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not remove symbolic link \"%s\": %m",
errmsg("could not remove symbolic link \"%s\": %m",
linkloc)));
}
#endif
@ -886,7 +899,8 @@ remove_tablespace_symlink(const char *linkloc)
{
/* Refuse to remove anything that's not a directory or symlink */
ereport(ERROR,
(errmsg("\"%s\" is not a directory or symbolic link",
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("\"%s\" is not a directory or symbolic link",
linkloc)));
}
}