On Tuesday, July 25, 2017 9:28:05 AM CEST Paul Eggert wrote: > * lib/fts.c (enum leaf_optimization): New type with three values. > (S_MAGIC_AFS): New macro. Sort them. > (leaf_optimization): Rename from leaf_optimization_applies, and > return enum leaf_optimization instead of bool. All uses changed. > Add cases for unknown type and for AFS. > (fts_build): Don’t rely on link counts if NO_LEAF_OPTIMIZATION.
Does this change (intentionally?) enable leaf optimization for CIFS? We have a bug report where find aborts while traversing a CIFS file system mounted on a directory on an XFS file system. The same 'find' command with the -noleaf option does not abort: https://bugzilla.redhat.com/1558249#c20 Kamil > --- > ChangeLog | 8 ++++++++ > lib/fts.c | 54 +++++++++++++++++++++++++++++++++++++----------------- > 2 files changed, 45 insertions(+), 17 deletions(-) > > diff --git a/ChangeLog b/ChangeLog > index 2c194327d..cbe4c9e27 100644 > --- a/ChangeLog > +++ b/ChangeLog > @@ -1,5 +1,13 @@ > 2017-07-24 Paul Eggert <egg...@cs.ucla.edu> > > + fts: three levels of leaf optimization > + * lib/fts.c (enum leaf_optimization): New type with three values. > + (S_MAGIC_AFS): New macro. Sort them. > + (leaf_optimization): Rename from leaf_optimization_applies, and > + return enum leaf_optimization instead of bool. All uses changed. > + Add cases for unknown type and for AFS. > + (fts_build): Don’t rely on link counts if NO_LEAF_OPTIMIZATION. > + > fts: cache dirent_inode_sort_may_be_useful too > * lib/fts.c (struct dev_type): New struct. > (DEV_TYPE_HT_INITIAL_SIZE): New constant. > diff --git a/lib/fts.c b/lib/fts.c > index a8de3f910..663a09b5e 100644 > --- a/lib/fts.c > +++ b/lib/fts.c > @@ -672,17 +672,32 @@ fts_close (FTS *sp) > ".."). */ > enum { MIN_DIR_NLINK = 2 }; > > +/* Whether leaf optimization is OK for a directory. */ > +enum leaf_optimization > + { > + /* st_nlink is not reliable for this directory's subdirectories. */ > + NO_LEAF_OPTIMIZATION, > + > + /* Leaf optimization is OK, but is not useful for avoiding stat calls. > */ + OK_LEAF_OPTIMIZATION, > + > + /* Leaf optimization is not only OK: it is useful for avoiding > + stat calls, because dirent.d_type does not work. */ > + NOSTAT_LEAF_OPTIMIZATION > + }; > + > #if defined __linux__ \ > && HAVE_SYS_VFS_H && HAVE_FSTATFS && HAVE_STRUCT_STATFS_F_TYPE > > # include <sys/vfs.h> > > /* Linux-specific constants from coreutils' src/fs.h */ > -# define S_MAGIC_TMPFS 0x1021994 > +# define S_MAGIC_AFS 0x5346414F > # define S_MAGIC_NFS 0x6969 > +# define S_MAGIC_PROC 0x9FA0 > # define S_MAGIC_REISERFS 0x52654973 > +# define S_MAGIC_TMPFS 0x1021994 > # define S_MAGIC_XFS 0x58465342 > -# define S_MAGIC_PROC 0x9FA0 > > /* Map a stat.st_dev number to a file system type number f_ftype. */ > struct dev_type > @@ -796,22 +811,24 @@ dirent_inode_sort_may_be_useful (FTSENT const *p) > dirent.d_type info. The optimization is valid if an st_nlink value > of at least MIN_DIR_NLINK is an upper bound on the number of > subdirectories of D, counting "." and ".." as subdirectories. */ > -static bool > -leaf_optimization_applies (FTSENT const *p) > +static enum leaf_optimization > +leaf_optimization (FTSENT const *p) > { > - /* FIXME: do we need to detect AFS mount points? I doubt it, > - unless fstatfs can report S_MAGIC_REISERFS for such a directory. */ > - > switch (filesystem_type (p)) > { > /* List here the file system types that lack usable dirent.d_type > info, yet for which the optimization does apply. */ > case S_MAGIC_REISERFS: > case S_MAGIC_XFS: > - return true; > + return NOSTAT_LEAF_OPTIMIZATION; > > - /* Explicitly list here any other file system type for which the > - optimization is not applicable, but need documentation. */ > + case 0: > + /* Leaf optimization is unsafe if the file system type is unknown. > */ + FALLTHROUGH; > + case S_MAGIC_AFS: > + /* Although AFS mount points are not counted in st_nlink, they > + act like directories. See <https://bugs.debian.org/143111>. */ > + FALLTHROUGH; > case S_MAGIC_NFS: > /* NFS provides usable dirent.d_type but not necessarily for all > entries of large directories, so as per > <https://bugzilla.redhat.com/1252549> @@ -821,9 +838,10 @@ > leaf_optimization_applies (FTSENT const *p) > case S_MAGIC_PROC: > /* Per <http://bugs.debian.org/143111> /proc may have > bogus stat.st_nlink values. */ > - FALLTHROUGH; > + return NO_LEAF_OPTIMIZATION; > + > default: > - return false; > + return OK_LEAF_OPTIMIZATION; > } > } > > @@ -833,10 +851,10 @@ dirent_inode_sort_may_be_useful (FTSENT const *p > _GL_UNUSED) { > return true; > } > -static bool > -leaf_optimization_applies (FTSENT const *p _GL_UNUSED) > +static enum leaf_optimization > +leaf_optimization (FTSENT const *p _GL_UNUSED) > { > - return false; > + return NO_LEAF_OPTIMIZATION; > } > #endif > > @@ -1028,7 +1046,8 @@ check_for_dir: > if (parent->fts_n_dirs_remaining == 0 > && ISSET(FTS_NOSTAT) > && ISSET(FTS_PHYSICAL) > - && leaf_optimization_applies (parent)) > + && (leaf_optimization (parent) > + == NOSTAT_LEAF_OPTIMIZATION)) > { > /* nothing more needed */ > } > @@ -1387,7 +1406,8 @@ fts_build (register FTS *sp, int type) > nlinks = 0; > /* Be quiet about nostat, GCC. */ > nostat = false; > - } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { > + } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL) > + && leaf_optimization (cur) != NO_LEAF_OPTIMIZATION) { > nlinks = (cur->fts_statp->st_nlink > - (ISSET (FTS_SEEDOT) ? 0 : MIN_DIR_NLINK)); > nostat = true;
