mirror of
git://sourceware.org/git/glibc.git
synced 2026-09-08 23:58:31 +08:00
Adhemerval Zanella
99303f3871
This patch synchronizes the glibc fts implementation with the latest version from gnulib (as of 2026-02-16). The primary motivation is to address limitations in the legacy glibc implementation, most notably BZ 22944, where fts fails with an ENAMETOOLONG error when traversing very long paths or deeply nested directory trees. The gnulib implementation dynamically reallocates path buffers and uses openat/fchdir optimizations, effectively lifting the MAXPATHLEN limitation. The gnulib implementation also added extra features, which are used by different GNU projects (coreutils, diffutils): * FTS_TIGHT_CYCLE_CHECK: used to enable a strict, immediate cycle-detection algorithm during a file system traversal. This is done internally using a hash table: every time the traversal enters a directory, it records the directory's device and inode (dev/ino) pair in the hash table, and before entering any directory, fts checks the hash table. * FTS_CWDFD: instead of actually changing the process's current working directory, it maintains a virtual current working directory using file descriptors. The file descriptor is store at the fts_cwd_fd field and all subsequent file operations are performed relative to this file descriptor using *at functions. * FTS_DEFER_STAT: performance-oriented flag that instructs the file tree traversal engine to delay fetching file metadata. When the flag is used, fts skips the immediate stat call. Instead, it marks the entry with a special internal state (FTS_NSOK and FTS_STAT_REQUIRED). The actual stat call is pushed down the line and executed by fts_read right before the application actually accesses the entry. * FTS_VERBATIM: fts_open accept and use the path strings exactly as they were provided in the arguments array without slash trimming. * FTS_MOUNT: it restrict the file tree walk to a single file system. Hopefully,it would allow some GNU projects to use the glibc implementation instead of pulling the gnulib one. It requires some changes to keep compatibility, compared to gnulib: * The new required fields are added at the end of FTS structure, and the new FTS flags are adjusted to avoid change FTS_NAMEONLY/FTS_STOP (even though they are marked as private). * The FTSENT uses a flexible array (fts_name), so two adjustments are required: the two new members (fts_fts and fts_dirp) are place *before* the struct and the fts_statp is now always allocated and accounted (the gnulib implementation uses an alwyas allocated member). Checked on x86_64-linux-gnu and i686-linux-gnu.
91 lines
2.9 KiB
C
91 lines
2.9 KiB
C
#ifndef _DIRENT_H
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# ifndef _ISOMAC
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# include <dirstream.h>
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# endif
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# include <dirent/dirent.h>
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# ifndef _ISOMAC
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# include <sys/stat.h>
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# include <stdbool.h>
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struct scandir_cancel_struct
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{
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DIR *dp;
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void *v;
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size_t cnt;
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};
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/* Now define the internal interfaces. */
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extern DIR *__opendir (const char *__name) attribute_hidden;
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extern DIR *__opendirat (int dfd, const char *__nam, int extra_flags,
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int *pnew_fd) attribute_hidden;
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extern DIR *__fdopendir (int __fd) attribute_hidden;
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extern int __closedir (DIR *__dirp) attribute_hidden;
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extern struct dirent *__readdir (DIR *__dirp) attribute_hidden;
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extern struct dirent *__readdir_unlocked (DIR *__dirp) attribute_hidden;
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extern struct dirent64 *__readdir64 (DIR *__dirp);
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libc_hidden_proto (__readdir64)
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extern int __readdir_r (DIR *__dirp, struct dirent *__entry,
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struct dirent **__result);
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extern int __readdir64_r (DIR *__dirp, struct dirent64 *__entry,
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struct dirent64 **__result);
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extern int __scandir64 (const char * __dir,
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struct dirent64 *** __namelist,
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int (*__selector) (const struct dirent64 *),
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int (*__cmp) (const struct dirent64 **,
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const struct dirent64 **));
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extern __ssize_t __getdirentries (int __fd, char *__restrict __buf,
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size_t __nbytes,
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__off_t *__restrict __basep)
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__THROW __nonnull ((2, 4));
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/* These functions are only implemented on Linux. */
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extern __ssize_t __getdents (int __fd, void *__buf, size_t __nbytes)
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attribute_hidden;
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extern __ssize_t __getdents64 (int __fd, void *__buf, size_t __nbytes);
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libc_hidden_proto (__getdents64)
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extern int __alphasort64 (const struct dirent64 **a, const struct dirent64 **b)
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__attribute_pure__;
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extern int __versionsort64 (const struct dirent64 **a,
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const struct dirent64 **b)
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__attribute_pure__;
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extern DIR *__alloc_dir (int fd, bool close_fd, int flags,
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const struct __stat64_t64 *statp)
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__nonnull (4) attribute_hidden;
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extern __typeof (rewinddir) __rewinddir;
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extern __typeof (seekdir) __seekdir;
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extern __typeof (dirfd) __dirfd;
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libc_hidden_proto (dirfd);
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extern void __scandir_cancel_handler (void *arg) attribute_hidden;
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extern int __scandir_tail (DIR *dp,
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struct dirent ***namelist,
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int (*select) (const struct dirent *),
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int (*cmp) (const struct dirent **,
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const struct dirent **))
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attribute_hidden;
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# if !_DIRENT_MATCHES_DIRENT64
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extern int __scandir_tail (DIR *dp,
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struct dirent ***namelist,
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int (*select) (const struct dirent *),
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int (*cmp) (const struct dirent **,
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const struct dirent **))
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attribute_hidden;
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# endif
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extern int __scandir64_tail (DIR *dp,
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struct dirent64 ***namelist,
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int (*select) (const struct dirent64 *),
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int (*cmp) (const struct dirent64 **,
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const struct dirent64 **))
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attribute_hidden;
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libc_hidden_proto (__rewinddir)
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extern __typeof (scandirat) __scandirat;
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# if IS_IN (rtld)
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extern __typeof (__rewinddir) __rewinddir attribute_hidden;
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# endif
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# endif
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#endif
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