From c61e14d3a8412cd50d98aab604e607692c844c8a Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 14 Apr 2024 21:33:30 +0200 Subject: Adding upstream version 2.40. Signed-off-by: Daniel Baumann --- libmount/src/tab_update.c | 318 +++++++++++++++++++++++++++++++++++++--------- 1 file changed, 255 insertions(+), 63 deletions(-) (limited to 'libmount/src/tab_update.c') diff --git a/libmount/src/tab_update.c b/libmount/src/tab_update.c index f5e5d30..87512af 100644 --- a/libmount/src/tab_update.c +++ b/libmount/src/tab_update.c @@ -35,9 +35,15 @@ struct libmnt_update { struct libmnt_fs *fs; char *filename; unsigned long mountflags; - int ready; + + int act_fd; + char *act_filename; + + unsigned int ready : 1, + missing_options : 1; struct libmnt_table *mountinfo; + struct libmnt_lock *lock; }; static int set_fs_root(struct libmnt_update *upd, struct libmnt_fs *fs, unsigned long mountflags); @@ -56,6 +62,7 @@ struct libmnt_update *mnt_new_update(void) if (!upd) return NULL; + upd->act_fd = -1; DBG(UPDATE, ul_debugobj(upd, "allocate")); return upd; } @@ -73,10 +80,14 @@ void mnt_free_update(struct libmnt_update *upd) DBG(UPDATE, ul_debugobj(upd, "free")); + mnt_unref_lock(upd->lock); mnt_unref_fs(upd->fs); mnt_unref_table(upd->mountinfo); + if (upd->act_fd >= 0) + close(upd->act_fd); free(upd->target); free(upd->filename); + free(upd->act_filename); free(upd); } @@ -173,7 +184,7 @@ int mnt_update_set_fs(struct libmnt_update *upd, unsigned long mountflags, mnt_unref_fs(upd->fs); free(upd->target); - upd->ready = FALSE; + upd->ready = 0; upd->fs = NULL; upd->target = NULL; upd->mountflags = 0; @@ -206,7 +217,7 @@ int mnt_update_set_fs(struct libmnt_update *upd, unsigned long mountflags, } DBG(UPDATE, ul_debugobj(upd, "ready")); - upd->ready = TRUE; + upd->ready = 1; return 0; } @@ -666,43 +677,42 @@ static int add_file_entry(struct libmnt_table *tb, struct libmnt_update *upd) return update_table(upd, tb); } -static int update_add_entry(struct libmnt_update *upd, struct libmnt_lock *lc) +static int update_add_entry(struct libmnt_update *upd) { struct libmnt_table *tb; int rc = 0; assert(upd); assert(upd->fs); + assert(upd->lock); DBG(UPDATE, ul_debugobj(upd, "%s: add entry", upd->filename)); - if (lc) - rc = mnt_lock_file(lc); + rc = mnt_lock_file(upd->lock); if (rc) return -MNT_ERR_LOCK; tb = __mnt_new_table_from_file(upd->filename, MNT_FMT_UTAB, 1); if (tb) rc = add_file_entry(tb, upd); - if (lc) - mnt_unlock_file(lc); + mnt_unlock_file(upd->lock); mnt_unref_table(tb); return rc; } -static int update_remove_entry(struct libmnt_update *upd, struct libmnt_lock *lc) +static int update_remove_entry(struct libmnt_update *upd) { struct libmnt_table *tb; int rc = 0; assert(upd); assert(upd->target); + assert(upd->lock); DBG(UPDATE, ul_debugobj(upd, "%s: remove entry", upd->filename)); - if (lc) - rc = mnt_lock_file(lc); + rc = mnt_lock_file(upd->lock); if (rc) return -MNT_ERR_LOCK; @@ -714,23 +724,22 @@ static int update_remove_entry(struct libmnt_update *upd, struct libmnt_lock *lc rc = update_table(upd, tb); } } - if (lc) - mnt_unlock_file(lc); + mnt_unlock_file(upd->lock); mnt_unref_table(tb); return rc; } -static int update_modify_target(struct libmnt_update *upd, struct libmnt_lock *lc) +static int update_modify_target(struct libmnt_update *upd) { struct libmnt_table *tb = NULL; int rc = 0; assert(upd); + assert(upd->lock); DBG(UPDATE, ul_debugobj(upd, "%s: modify target", upd->filename)); - if (lc) - rc = mnt_lock_file(lc); + rc = mnt_lock_file(upd->lock); if (rc) return -MNT_ERR_LOCK; @@ -779,14 +788,13 @@ static int update_modify_target(struct libmnt_update *upd, struct libmnt_lock *l } done: - if (lc) - mnt_unlock_file(lc); - + mnt_unlock_file(upd->lock); mnt_unref_table(tb); return rc; } -static int update_modify_options(struct libmnt_update *upd, struct libmnt_lock *lc) +/* replaces option in the table entry by new options from @udp */ +static int update_modify_options(struct libmnt_update *upd) { struct libmnt_table *tb = NULL; int rc = 0; @@ -794,13 +802,13 @@ static int update_modify_options(struct libmnt_update *upd, struct libmnt_lock * assert(upd); assert(upd->fs); + assert(upd->lock); DBG(UPDATE, ul_debugobj(upd, "%s: modify options", upd->filename)); fs = upd->fs; - if (lc) - rc = mnt_lock_file(lc); + rc = mnt_lock_file(upd->lock); if (rc) return -MNT_ERR_LOCK; @@ -819,11 +827,77 @@ static int update_modify_options(struct libmnt_update *upd, struct libmnt_lock * rc = add_file_entry(tb, upd); /* not found, add new */ } - if (lc) - mnt_unlock_file(lc); + mnt_unlock_file(upd->lock); + mnt_unref_table(tb); + return rc; +} + +/* add user options missing in the table entry by new options from @udp */ +static int update_add_options(struct libmnt_update *upd) +{ + struct libmnt_table *tb = NULL; + int rc = 0; + struct libmnt_fs *fs; + + assert(upd); + assert(upd->fs); + assert(upd->lock); + + if (!upd->fs->user_optstr) + return 0; + DBG(UPDATE, ul_debugobj(upd, "%s: add options", upd->filename)); + + fs = upd->fs; + + rc = mnt_lock_file(upd->lock); + if (rc) + return -MNT_ERR_LOCK; + + tb = __mnt_new_table_from_file(upd->filename, MNT_FMT_UTAB, 1); + if (tb) { + struct libmnt_fs *cur = mnt_table_find_target(tb, + mnt_fs_get_target(fs), + MNT_ITER_BACKWARD); + if (cur) { + char *u = NULL; + + rc = mnt_optstr_get_missing(cur->user_optstr, upd->fs->user_optstr, &u); + if (!rc && u) { + DBG(UPDATE, ul_debugobj(upd, " add missing: %s", u)); + rc = mnt_optstr_append_option(&cur->user_optstr, u, NULL); + } + if (!rc && u) + rc = update_table(upd, tb); + + if (rc == 1) /* nothing is missing */ + rc = 0; + } else + rc = add_file_entry(tb, upd); /* not found, add new */ + } + + mnt_unlock_file(upd->lock); mnt_unref_table(tb); return rc; + +} + +static int update_init_lock(struct libmnt_update *upd, struct libmnt_lock *lc) +{ + assert(upd); + + if (lc) { + mnt_unref_lock(upd->lock); + mnt_ref_lock(lc); + upd->lock = lc; + } else if (!upd->lock) { + upd->lock = mnt_new_lock(upd->filename, 0); + if (!upd->lock) + return -ENOMEM; + mnt_lock_block_signals(upd->lock, TRUE); + } + + return 0; } /** @@ -842,7 +916,6 @@ static int update_modify_options(struct libmnt_update *upd, struct libmnt_lock * */ int mnt_update_table(struct libmnt_update *upd, struct libmnt_lock *lc) { - struct libmnt_lock *lc0 = lc; int rc = -EINVAL; if (!upd || !upd->filename) @@ -854,33 +927,32 @@ int mnt_update_table(struct libmnt_update *upd, struct libmnt_lock *lc) if (upd->fs) { DBG(UPDATE, mnt_fs_print_debug(upd->fs, stderr)); } - if (!lc) { - lc = mnt_new_lock(upd->filename, 0); - if (lc) - mnt_lock_block_signals(lc, TRUE); - } + + rc = update_init_lock(upd, lc); + if (rc) + goto done; if (!upd->fs && upd->target) - rc = update_remove_entry(upd, lc); /* umount */ + rc = update_remove_entry(upd); /* umount */ else if (upd->mountflags & MS_MOVE) - rc = update_modify_target(upd, lc); /* move */ + rc = update_modify_target(upd); /* move */ else if (upd->mountflags & MS_REMOUNT) - rc = update_modify_options(upd, lc); /* remount */ + rc = update_modify_options(upd); /* remount */ + else if (upd->fs && upd->missing_options) + rc = update_add_options(upd); /* mount by externel helper */ else if (upd->fs) - rc = update_add_entry(upd, lc); /* mount */ + rc = update_add_entry(upd); /* mount */ - upd->ready = FALSE; + upd->ready = 1; +done: DBG(UPDATE, ul_debugobj(upd, "%s: update tab: done [rc=%d]", upd->filename, rc)); - if (lc != lc0) - mnt_free_lock(lc); return rc; } -int mnt_update_already_done(struct libmnt_update *upd, struct libmnt_lock *lc) +int mnt_update_already_done(struct libmnt_update *upd) { struct libmnt_table *tb = NULL; - struct libmnt_lock *lc0 = lc; int rc = 0; if (!upd || !upd->filename || (!upd->fs && !upd->target)) @@ -888,37 +960,32 @@ int mnt_update_already_done(struct libmnt_update *upd, struct libmnt_lock *lc) DBG(UPDATE, ul_debugobj(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) { - rc = mnt_lock_file(lc); - if (rc) { - rc = -MNT_ERR_LOCK; - goto done; - } - } - tb = __mnt_new_table_from_file(upd->filename, MNT_FMT_UTAB, 1); - if (lc) - mnt_unlock_file(lc); if (!tb) goto done; if (upd->fs) { /* mount */ + struct libmnt_fs *fs; 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)) { + fs = mnt_table_find_pair(tb, src, tgt, MNT_ITER_BACKWARD); + if (fs) { DBG(UPDATE, ul_debugobj(upd, "%s: found %s %s", upd->filename, src, tgt)); + + /* Check if utab entry (probably writen by /sbin/mount. + * helper) contains all options expected by this update */ + if (mnt_optstr_get_missing(fs->user_optstr, upd->fs->user_optstr, NULL) == 0) { + upd->missing_options = 1; + DBG(UPDATE, ul_debugobj(upd, " missing options detected")); + } + } else rc = 1; - } + } else if (upd->target) { /* umount */ if (!mnt_table_find_target(tb, upd->target, MNT_ITER_BACKWARD)) { @@ -930,13 +997,133 @@ int mnt_update_already_done(struct libmnt_update *upd, struct libmnt_lock *lc) mnt_unref_table(tb); done: - if (lc && lc != lc0) - mnt_free_lock(lc); DBG(UPDATE, ul_debugobj(upd, "%s: previous update check done [rc=%d]", upd->filename, rc)); return rc; } +int mnt_update_emit_event(struct libmnt_update *upd) +{ + char *filename; + int fd; + + if (!upd || !upd->filename) + return -EINVAL; + + if (asprintf(&filename, "%s.event", upd->filename) <= 0) + return -ENOMEM; + + DBG(UPDATE, ul_debugobj(upd, "emitting utab event")); + + fd = open(filename, O_WRONLY|O_CREAT|O_CLOEXEC, + S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH); + free(filename); + if (fd < 0) + return -errno; + close(fd); + return 0; +} + +/* + * Let's use /run/mount/utab.act file to report to libmount monitor that + * libmount is working with utab. In this case, the monitor can ignore all + * events from kernel until entire mount (with all steps) is done. + * + * For example mount NFS with x-* options, means + * - create utab.act and mark it as used (by LOCK_SH) + * - exec /sbin/mount.nfs + * - call mount(2) (kernel event on /proc/self/mounts) + * - utab update (NFS stuff) + * - utab update (add x-* userspace options) + * - unlink utab.act (if not use anyone else) + * - release event by /run/mount/utab.event + * + * Note, this is used only when utab is in the game (x-* options). + */ +int mnt_update_start(struct libmnt_update *upd) +{ + int rc = 0; + mode_t oldmask; + + if (!upd || !upd->filename) + return -EINVAL; + + if (!upd->act_filename && + asprintf(&upd->act_filename, "%s.act", upd->filename) <= 0) + return -ENOMEM; + + /* Use exclusive lock to avoid some other proces will remove the the + * file before it's marked as used by LOCK_SH (below) */ + rc = update_init_lock(upd, NULL); + if (rc) + return rc; + + rc = mnt_lock_file(upd->lock); + if (rc) + return -MNT_ERR_LOCK; + + DBG(UPDATE, ul_debugobj(upd, "creating act file")); + + oldmask = umask(S_IRGRP|S_IWGRP|S_IXGRP|S_IROTH|S_IWOTH|S_IXOTH); + upd->act_fd = open(upd->act_filename, O_WRONLY|O_CREAT|O_CLOEXEC, S_IRUSR|S_IWUSR); + umask(oldmask); + + if (upd->act_fd < 0) { + rc = -errno; + goto fail; + } + + /* mark the file as used */ + rc = flock(upd->act_fd, LOCK_SH); + if (rc) { + rc = -errno; + goto fail; + } + + mnt_unlock_file(upd->lock); + return 0; +fail: + DBG(UPDATE, ul_debugobj(upd, "act file failed [rc=%d]", rc)); + mnt_unlock_file(upd->lock); + unlink(upd->act_filename); + if (upd->act_fd >= 0) + close(upd->act_fd); + upd->act_fd = -1; + return rc; +} + +int mnt_update_end(struct libmnt_update *upd) +{ + int rc; + + if (!upd || upd->act_fd < 0) + return -EINVAL; + + DBG(UPDATE, ul_debugobj(upd, "removing act file")); + + /* make sure nobody else will use the file */ + rc = mnt_lock_file(upd->lock); + if (rc) + return -MNT_ERR_LOCK; + + /* mark the file as unused */ + flock(upd->act_fd, LOCK_UN); + errno = 0; + + /* check if nobody else need the file (if yes, then the file is under LOCK_SH) )*/ + if (flock(upd->act_fd, LOCK_EX | LOCK_NB) != 0) { + if (errno == EWOULDBLOCK) + DBG(UPDATE, ul_debugobj(upd, "act file used, no unlink")); + } else { + DBG(UPDATE, ul_debugobj(upd, "unlinking act file")); + unlink(upd->act_filename); + } + + mnt_unlock_file(upd->lock); + close(upd->act_fd); + upd->act_fd = -1; + return 0; +} #ifdef TEST_PROGRAM @@ -970,7 +1157,8 @@ done: return rc; } -static int test_add(struct libmnt_test *ts, int argc, char *argv[]) +static int test_add(struct libmnt_test *ts __attribute__((unused)), + int argc, char *argv[]) { struct libmnt_fs *fs = mnt_new_fs(); int rc; @@ -987,14 +1175,16 @@ static int test_add(struct libmnt_test *ts, int argc, char *argv[]) return rc; } -static int test_remove(struct libmnt_test *ts, int argc, char *argv[]) +static int test_remove(struct libmnt_test *ts __attribute__((unused)), + int argc, char *argv[]) { if (argc < 2) return -1; return update(argv[1], NULL, 0); } -static int test_move(struct libmnt_test *ts, int argc, char *argv[]) +static int test_move(struct libmnt_test *ts __attribute__((unused)), + int argc, char *argv[]) { struct libmnt_fs *fs = mnt_new_fs(); int rc; @@ -1010,7 +1200,8 @@ static int test_move(struct libmnt_test *ts, int argc, char *argv[]) return rc; } -static int test_remount(struct libmnt_test *ts, int argc, char *argv[]) +static int test_remount(struct libmnt_test *ts __attribute__((unused)), + int argc, char *argv[]) { struct libmnt_fs *fs = mnt_new_fs(); int rc; @@ -1025,7 +1216,8 @@ static int test_remount(struct libmnt_test *ts, int argc, char *argv[]) return rc; } -static int test_replace(struct libmnt_test *ts, int argc, char *argv[]) +static int test_replace(struct libmnt_test *ts __attribute__((unused)), + int argc, char *argv[]) { struct libmnt_fs *fs = mnt_new_fs(); struct libmnt_table *tb = mnt_new_table(); -- cgit v1.2.3