From e49db109bba7ff0b84fe7ba4f1f08405a6b72419 Mon Sep 17 00:00:00 2001 From: Dominique Martinet Date: Fri, 27 Oct 2023 06:42:35 +0900 Subject: [PATCH] find: fix -xdev -depth (and -delete) find -xdev with -depth would check for same_fs after the subdirectory has been processed (because the check is done in the file/dir action, which is evaluated too late in the -depth case) This renders `find -xdev -delete` useless, as reported in 2012 here: https://bugs.busybox.net/show_bug.cgi?id=5756 The bug report suggested adding an extra hook, which would be required if we were to keep the current xdev approach that allows all filesystems given in argument, but GNU findutils and OpenBSD find actually stop on the first filesystem boundary e.g. for the following tree: $ find test -exec stat --format "%d %n" {} + 27 test 27 test/file 59 test/tmpfs 27 test/tmpfs/bind 27 test/tmpfs/bind/file 59 test/tmpfs/file (Where 'test/tmpfs' is a tmpfs, and 'test/tmpfs/bind' is a bind mount to a neighboring directory in the same filesystem as 'test' -- also tested with a symlink and -follow for openbsd which has no bind mount) Then `find test test/tmpfs -xdev` does not print test/tmpfs/bind/file. This makes the implementation much simpler (although it's a bit ugly to carry the parent st_dev as an argument to the function) and smaller code, and would allow for easy addition of rm/cp --one-file-system if we want to do that later. Note: this also no longer stores the stat result in 'status' in recursive_action1 as that was not used and doing this saves 10 bytes function old new delta recursive_action1 361 385 +24 parse_params 1503 1510 +7 recursive_action 63 65 +2 fileAction 206 127 -79 find_main 520 417 -103 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 3/2 up/down: 33/-182) Total: -149 bytes text data bss dec hex filename 78267 1582 1552 81401 13df9 busybox_old 78118 1582 1552 81252 13d64 busybox_unstripped --- findutils/find.c | 44 ++-------------------------------------- include/libbb.h | 1 + libbb/recursive_action.c | 19 ++++++++++------- 3 files changed, 15 insertions(+), 49 deletions(-) diff --git a/findutils/find.c b/findutils/find.c index bb6ad31e5edc..e88fbd3ba3bf 100644 --- a/findutils/find.c +++ b/findutils/find.c @@ -488,7 +488,6 @@ struct globals { #endif action ***actions; smallint need_print; - smallint xdev_on; smalluint exitstatus; recurse_flags_t recurse_flags; IF_FEATURE_FIND_EXEC_PLUS(unsigned max_argv_len;) @@ -988,26 +987,10 @@ static int FAST_FUNC fileAction( struct stat *statbuf) { int r; - int same_fs = 1; - -#if ENABLE_FEATURE_FIND_XDEV - if (S_ISDIR(statbuf->st_mode) && G.xdev_count) { - int i; - for (i = 0; i < G.xdev_count; i++) { - if (G.xdev_dev[i] == statbuf->st_dev) - goto found; - } - //bb_error_msg("'%s': not same fs", fileName); - same_fs = 0; - found: ; - } -#endif #if ENABLE_FEATURE_FIND_MAXDEPTH if (state->depth < G.minmaxdepth[0]) { - if (same_fs) - return TRUE; /* skip this, continue recursing */ - return SKIP; /* stop recursing */ + return TRUE; /* skip this, continue recursing */ } if (state->depth > G.minmaxdepth[1]) return SKIP; /* stop recursing */ @@ -1024,11 +1007,6 @@ static int FAST_FUNC fileAction( return SKIP; } #endif - /* -xdev stops on mountpoints, but AFTER mountpoit itself - * is processed as usual */ - if (!same_fs) { - return SKIP; - } /* Cannot return 0: our caller, recursive_action(), * will perror() and skip dirs (if called on dir) */ @@ -1266,7 +1244,7 @@ static action*** parse_params(char **argv) #if ENABLE_FEATURE_FIND_XDEV else if (parm == OPT_XDEV) { dbg("%d", __LINE__); - G.xdev_on = 1; + G.recurse_flags |= ACTION_XDEV; } #endif #if ENABLE_FEATURE_FIND_MAXDEPTH @@ -1685,24 +1663,6 @@ int find_main(int argc UNUSED_PARAM, char **argv) G.actions = parse_params(&argv[firstopt]); argv[firstopt] = NULL; -#if ENABLE_FEATURE_FIND_XDEV - if (G.xdev_on) { - struct stat stbuf; - - G.xdev_count = firstopt; - G.xdev_dev = xzalloc(G.xdev_count * sizeof(G.xdev_dev[0])); - for (i = 0; argv[i]; i++) { - /* not xstat(): shouldn't bomb out on - * "find not_exist exist -xdev" */ - if (stat(argv[i], &stbuf) == 0) - G.xdev_dev[i] = stbuf.st_dev; - /* else G.xdev_dev[i] stays 0 and - * won't match any real device dev_t - */ - } - } -#endif - for (i = 0; argv[i]; i++) { if (!recursive_action(argv[i], G.recurse_flags,/* flags */ diff --git a/include/libbb.h b/include/libbb.h index 5d0fe924eed1..d903330cccb0 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -512,6 +512,7 @@ enum { ACTION_DEPTHFIRST = (1 << 3), ACTION_QUIET = (1 << 4), ACTION_DANGLING_OK = (1 << 5), + ACTION_XDEV = (1 << 6), }; typedef uint8_t recurse_flags_t; typedef struct recursive_state { diff --git a/libbb/recursive_action.c b/libbb/recursive_action.c index b1c4bfad7ccf..d4b40afdead3 100644 --- a/libbb/recursive_action.c +++ b/libbb/recursive_action.c @@ -62,13 +62,15 @@ static int FAST_FUNC true_action(struct recursive_state *state UNUSED_PARAM, * ACTION_FOLLOWLINKS mainly controls handling of links to dirs. * 0: lstat(statbuf). Calls fileAction on link name even if points to dir. * 1: stat(statbuf). Calls dirAction and optionally recurse on link to dir. + * + * If ACTION_XDEV, stop on different filesystem _after_ it has been processed */ -static int recursive_action1(recursive_state_t *state, const char *fileName) +static int recursive_action1(recursive_state_t *state, const char *fileName, dev_t parentDev) { struct stat statbuf; unsigned follow; - int status; + int status = TRUE; DIR *dir; struct dirent *next; @@ -76,8 +78,7 @@ static int recursive_action1(recursive_state_t *state, const char *fileName) if (state->depth == 0) follow = ACTION_FOLLOWLINKS | ACTION_FOLLOWLINKS_L0; follow &= state->flags; - status = (follow ? stat : lstat)(fileName, &statbuf); - if (status < 0) { + if ((follow ? stat : lstat)(fileName, &statbuf) < 0) { #ifdef DEBUG_RECURS_ACTION bb_error_msg("status=%d flags=%x", status, state->flags); #endif @@ -114,6 +115,10 @@ static int recursive_action1(recursive_state_t *state, const char *fileName) return TRUE; } + /* skip cross devices -- we still need to process action */ + if ((state->flags & ACTION_XDEV) && parentDev != 0 && statbuf.st_dev != parentDev) + goto skip_recurse; + dir = opendir(fileName); if (!dir) { /* findutils-4.1.20 reports this */ @@ -121,7 +126,6 @@ static int recursive_action1(recursive_state_t *state, const char *fileName) /* To trigger: "find -exec rm -rf {} \;" */ goto done_nak_warn; } - status = TRUE; while ((next = readdir(dir)) != NULL) { char *nextFile; int s; @@ -132,7 +136,7 @@ static int recursive_action1(recursive_state_t *state, const char *fileName) /* process every file (NB: ACTION_RECURSE is set in flags) */ state->depth++; - s = recursive_action1(state, nextFile); + s = recursive_action1(state, nextFile, statbuf.st_dev); if (s == FALSE) status = FALSE; free(nextFile); @@ -146,6 +150,7 @@ static int recursive_action1(recursive_state_t *state, const char *fileName) } closedir(dir); +skip_recurse: if (state->flags & ACTION_DEPTHFIRST) { if (!state->dirAction(state, fileName, &statbuf)) goto done_nak_warn; @@ -177,5 +182,5 @@ int FAST_FUNC recursive_action(const char *fileName, state.fileAction = fileAction ? fileAction : true_action; state.dirAction = dirAction ? dirAction : true_action; - return recursive_action1(&state, fileName); + return recursive_action1(&state, fileName, 0); } -- 2.39.2