From: Florian Weimer <fweimer@redhat.com>
To: libc-alpha@sourceware.org
Subject: [PATCH] Linux: Do not skip d_ino == 0 entries in readdir, readdir64 (bug 12165)
Date: Mon, 19 Sep 2022 08:54:52 +0200 [thread overview]
Message-ID: <87o7vbj1kz.fsf@oldenburg.str.redhat.com> (raw)
POSIX does not say this value is special. For example, old XFS file
systems may still use inode number zero.
Also update the comment regarding ENOENT. Linux may return ENOENT
for some file systems.
Tested on i686-linux-gnu and x86_64-linux-gnu.
---
sysdeps/unix/sysv/linux/readdir.c | 57 +++++++----------
sysdeps/unix/sysv/linux/readdir64.c | 120 +++++++++++++++---------------------
2 files changed, 69 insertions(+), 108 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/readdir.c b/sysdeps/unix/sysv/linux/readdir.c
index b480135164..15f0033f36 100644
--- a/sysdeps/unix/sysv/linux/readdir.c
+++ b/sysdeps/unix/sysv/linux/readdir.c
@@ -28,48 +28,33 @@ __readdir_unlocked (DIR *dirp)
struct dirent *dp;
int saved_errno = errno;
- do
+ if (dirp->offset >= dirp->size)
{
- size_t reclen;
+ /* We've emptied out our buffer. Refill it. */
- if (dirp->offset >= dirp->size)
+ size_t maxread = dirp->allocation;
+ ssize_t bytes;
+
+ bytes = __getdents (dirp->fd, dirp->data, maxread);
+ if (bytes <= 0)
{
- /* We've emptied out our buffer. Refill it. */
-
- size_t maxread = dirp->allocation;
- ssize_t bytes;
-
- bytes = __getdents (dirp->fd, dirp->data, maxread);
- if (bytes <= 0)
- {
- /* On some systems getdents fails with ENOENT when the
- open directory has been rmdir'd already. POSIX.1
- requires that we treat this condition like normal EOF. */
- if (bytes < 0 && errno == ENOENT)
- bytes = 0;
-
- /* Don't modifiy errno when reaching EOF. */
- if (bytes == 0)
- __set_errno (saved_errno);
- dp = NULL;
- break;
- }
- dirp->size = (size_t) bytes;
-
- /* Reset the offset into the buffer. */
- dirp->offset = 0;
+ /* Linux fails with ENOENT if IS_DEADDIR is true for the
+ directory inode. POSIX treats this as a regular
+ end-of-directory condition, so do not set errno in that
+ case, to indicate success. */
+ if (bytes == 0 || errno == ENOENT)
+ __set_errno (saved_errno);
+ return NULL;
}
+ dirp->size = (size_t) bytes;
- dp = (struct dirent *) &dirp->data[dirp->offset];
+ /* Reset the offset into the buffer. */
+ dirp->offset = 0;
+ }
- reclen = dp->d_reclen;
-
- dirp->offset += reclen;
-
- dirp->filepos = dp->d_off;
-
- /* Skip deleted files. */
- } while (dp->d_ino == 0);
+ dp = (struct dirent *) &dirp->data[dirp->offset];
+ dirp->offset += dp->d_reclen;
+ dirp->filepos = dp->d_off;
return dp;
}
diff --git a/sysdeps/unix/sysv/linux/readdir64.c b/sysdeps/unix/sysv/linux/readdir64.c
index 52b11eb9d9..f56c3c0d8e 100644
--- a/sysdeps/unix/sysv/linux/readdir64.c
+++ b/sysdeps/unix/sysv/linux/readdir64.c
@@ -37,48 +37,36 @@ __readdir64 (DIR *dirp)
__libc_lock_lock (dirp->lock);
#endif
- do
+ if (dirp->offset >= dirp->size)
{
- size_t reclen;
+ /* We've emptied out our buffer. Refill it. */
- if (dirp->offset >= dirp->size)
+ size_t maxread = dirp->allocation;
+ ssize_t bytes;
+
+ bytes = __getdents64 (dirp->fd, dirp->data, maxread);
+ if (bytes <= 0)
{
- /* We've emptied out our buffer. Refill it. */
-
- size_t maxread = dirp->allocation;
- ssize_t bytes;
-
- bytes = __getdents64 (dirp->fd, dirp->data, maxread);
- if (bytes <= 0)
- {
- /* On some systems getdents fails with ENOENT when the
- open directory has been rmdir'd already. POSIX.1
- requires that we treat this condition like normal EOF. */
- if (bytes < 0 && errno == ENOENT)
- bytes = 0;
-
- /* Don't modifiy errno when reaching EOF. */
- if (bytes == 0)
- __set_errno (saved_errno);
- dp = NULL;
- break;
- }
- dirp->size = (size_t) bytes;
-
- /* Reset the offset into the buffer. */
- dirp->offset = 0;
+ /* Linux fails with ENOENT if IS_DEADDIR is true for the
+ directory inode. POSIX treats this as a regular
+ end-of-directory condition, so do not set errno in that
+ case, to indicate success. */
+ if (bytes == 0 || errno == ENOENT)
+ __set_errno (saved_errno);
+#if IS_IN (libc)
+ __libc_lock_unlock (dirp->lock);
+#endif
+ return NULL;
}
+ dirp->size = (size_t) bytes;
- dp = (struct dirent64 *) &dirp->data[dirp->offset];
+ /* Reset the offset into the buffer. */
+ dirp->offset = 0;
+ }
- reclen = dp->d_reclen;
-
- dirp->offset += reclen;
-
- dirp->filepos = dp->d_off;
-
- /* Skip deleted files. */
- } while (dp->d_ino == 0);
+ dp = (struct dirent64 *) &dirp->data[dirp->offset];
+ dirp->offset += dp->d_reclen;
+ dirp->filepos = dp->d_off;
#if IS_IN (libc)
__libc_lock_unlock (dirp->lock);
@@ -115,48 +103,36 @@ __old_readdir64 (DIR *dirp)
__libc_lock_lock (dirp->lock);
#endif
- do
+ if (dirp->offset >= dirp->size)
{
- size_t reclen;
+ /* We've emptied out our buffer. Refill it. */
- if (dirp->offset >= dirp->size)
+ size_t maxread = dirp->allocation;
+ ssize_t bytes;
+
+ bytes = __old_getdents64 (dirp->fd, dirp->data, maxread);
+ if (bytes <= 0)
{
- /* We've emptied out our buffer. Refill it. */
-
- size_t maxread = dirp->allocation;
- ssize_t bytes;
-
- bytes = __old_getdents64 (dirp->fd, dirp->data, maxread);
- if (bytes <= 0)
- {
- /* On some systems getdents fails with ENOENT when the
- open directory has been rmdir'd already. POSIX.1
- requires that we treat this condition like normal EOF. */
- if (bytes < 0 && errno == ENOENT)
- bytes = 0;
-
- /* Don't modifiy errno when reaching EOF. */
- if (bytes == 0)
- __set_errno (saved_errno);
- dp = NULL;
- break;
- }
- dirp->size = (size_t) bytes;
-
- /* Reset the offset into the buffer. */
- dirp->offset = 0;
+ /* Linux fails with ENOENT if IS_DEADDIR is true for the
+ directory inode. POSIX treats this as a regular
+ end-of-directory condition, so do not set errno in that
+ case, to indicate success. */
+ if (bytes == 0 || errno == ENOENT)
+ __set_errno (saved_errno);
+#if IS_IN (libc)
+ __libc_lock_unlock (dirp->lock);
+#endif
+ return NULL;
}
+ dirp->size = (size_t) bytes;
- dp = (struct __old_dirent64 *) &dirp->data[dirp->offset];
+ /* Reset the offset into the buffer. */
+ dirp->offset = 0;
+ }
- reclen = dp->d_reclen;
-
- dirp->offset += reclen;
-
- dirp->filepos = dp->d_off;
-
- /* Skip deleted files. */
- } while (dp->d_ino == 0);
+ dp = (struct __old_dirent64 *) &dirp->data[dirp->offset];
+ dirp->offset += dp->d_reclen;
+ dirp->filepos = dp->d_off;
#if IS_IN (libc)
__libc_lock_unlock (dirp->lock);
base-commit: 2ff6775ad341b10a08e3b27d6e1df1da637747c7
next reply other threads:[~2022-09-19 6:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-19 6:54 Florian Weimer [this message]
2022-09-19 8:26 ` Andreas Schwab
2022-09-19 8:30 ` Florian Weimer
2022-09-19 8:53 ` Andreas Schwab
2022-09-19 9:30 ` Florian Weimer
2022-09-19 9:58 ` Andreas Schwab
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