From 7e0c06194f5e65eb2a9ae38515d78f4ef301c809 Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Mon, 4 Nov 2013 12:45:33 +0100 Subject: libmount: update utab after successful extern helper mount This patch allows to maintain private utab libmount file also for external mount/umount helpers that are not linked with libmount. The libmount check if utab has been updated after successful extern helper execution (status=0). If not then the file is updated. This patch affects only 'user' fstab mount option. So, for example with suid mount.cifs you can use: //server/foo /mnt cifs username=foo,noauto,user Signed-off-by: Karel Zak --- libmount/src/tab_update.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) (limited to 'libmount/src/tab_update.c') diff --git a/libmount/src/tab_update.c b/libmount/src/tab_update.c index 13f6f6ebe..bbe0cb2d7 100644 --- a/libmount/src/tab_update.c +++ b/libmount/src/tab_update.c @@ -286,6 +286,7 @@ int mnt_update_force_rdonly(struct libmnt_update *upd, int rdonly) return rc; } + /* * Allocates an utab entry (upd->fs) for mount/remount. This function should be * called *before* mount(2) syscall. The @fs is used as a read-only template. @@ -873,6 +874,67 @@ int mnt_update_table(struct libmnt_update *upd, struct libmnt_lock *lc) return rc; } +int mnt_update_already_done(struct libmnt_update *upd, struct libmnt_lock *lc) +{ + struct libmnt_table *tb = NULL; + struct libmnt_lock *lc0 = lc; + int rc = 0; + + if (!upd || !upd->filename || (!upd->fs && !upd->target)) + return -EINVAL; + + DBG(UPDATE, mnt_debug_h(upd, "%s: checking for previous update", upd->filename)); + + if (!lc) { + lc = mnt_new_lock(upd->filename, 0); + if (lc) + mnt_lock_block_signals(lc, TRUE); + } + if (lc && upd->userspace_only) + mnt_lock_use_simplelock(lc, TRUE); /* use flock */ + if (lc) + rc = mnt_lock_file(lc); + if (rc) + goto done; + + tb = __mnt_new_table_from_file(upd->filename, + upd->userspace_only ? MNT_FMT_UTAB : MNT_FMT_MTAB); + if (lc) + mnt_unlock_file(lc); + if (!tb) + goto done; + + if (upd->fs) { + /* mount */ + const char *tgt = mnt_fs_get_target(upd->fs); + const char *src = mnt_fs_get_bindsrc(upd->fs) ? + mnt_fs_get_bindsrc(upd->fs) : + mnt_fs_get_source(upd->fs); + + if (mnt_table_find_pair(tb, src, tgt, MNT_ITER_BACKWARD)) { + DBG(UPDATE, mnt_debug_h(upd, "%s: found %s %s", + upd->filename, src, tgt)); + rc = 1; + } + } else if (upd->target) { + /* umount */ + if (!mnt_table_find_target(tb, upd->target, MNT_ITER_BACKWARD)) { + DBG(UPDATE, mnt_debug_h(upd, "%s: not-found (umounted) %s", + upd->filename, upd->target)); + rc = 1; + } + } + + mnt_unref_table(tb); +done: + if (lc && lc != lc0) + mnt_free_lock(lc); + DBG(UPDATE, mnt_debug_h(upd, "%s: previous update check done [rc=%d]", + upd->filename, rc)); + return rc; +} + + #ifdef TEST_PROGRAM static int update(const char *target, struct libmnt_fs *fs, unsigned long mountflags) -- cgit v1.2.3-55-g7522