From 251c3931fedc9275bd57bc75c2153674a540bbce Mon Sep 17 00:00:00 2001
From: "Dmitry V. Levin" <ldv@altlinux.org>
Date: Thu, 18 May 2017 17:19:25 +0300
Subject: [PATCH] quotaops: check return code of ftruncate and lseek calls
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ftruncate and lseek syscalls may fail for different reasons,
do not ignore these errors. Create a helper function and use it
instead of duplicating error checks and diagnostic messages.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Petr Písař <ppisar@redhat.com>
---
quotaops.c | 53 +++++++++++++++++++++++++++++------------------------
1 file changed, 29 insertions(+), 24 deletions(-)
diff --git a/quotaops.c b/quotaops.c
index 6f245b7..81d7be0 100644
--- a/quotaops.c
+++ b/quotaops.c
@@ -252,6 +252,28 @@ int editprivs(char *tmpfile)
}
/*
+ * Duplicate a file descriptor, resetting the file offset.
+ * If it's a write descriptor, also truncate the file.
+ */
+static FILE *dup_file(int fd, int is_write)
+{
+ FILE *fp;
+
+ if (is_write && ftruncate(fd, 0))
+ die(1, _("Cannot truncate a file: %s\n"), strerror(errno));
+ if (lseek(fd, 0, SEEK_SET))
+ die(1, _("Cannot reset a file offset: %s\n"), strerror(errno));
+ if ((fd = dup(fd)) < 0)
+ die(1, _("Cannot duplicate a file descriptor: %s\n"), strerror(errno));
+ if (!(fp = fdopen(fd, is_write ? "w" : "r")))
+ die(1, is_write ? _("Cannot open a stream to write to: %s\n")
+ : _("Cannot open a stream to read from: %s\n"),
+ strerror(errno));
+
+ return fp;
+}
+
+/*
* Convert a dquot list to an ASCII file.
*/
int writeprivs(struct dquot *qlist, int outfd, char *name, int quotatype)
@@ -259,10 +281,7 @@ int writeprivs(struct dquot *qlist, int outfd, char *name, int quotatype)
struct dquot *q;
FILE *fd;
- ftruncate(outfd, 0);
- lseek(outfd, 0, SEEK_SET);
- if (!(fd = fdopen(dup(outfd), "w")))
- die(1, _("Cannot duplicate descriptor of file to write to: %s\n"), strerror(errno));
+ fd = dup_file(outfd, 1);
fprintf(fd, _("Disk quotas for %s %s (%cid %d):\n"),
_(type2name(quotatype)), name, *type2name(quotatype), qlist->dq_id);
@@ -323,9 +342,7 @@ int readprivs(struct dquot *qlist, int infd)
char inodesstring[BUFSIZ], isoftstring[BUFSIZ], ihardstring[BUFSIZ];
const char *error;
- lseek(infd, 0, SEEK_SET);
- if (!(fd = fdopen(dup(infd), "r")))
- die(1, _("Cannot duplicate descriptor of temp file: %s\n"), strerror(errno));
+ fd = dup_file(infd, 0);
/*
* Discard title lines, then read lines to process.
@@ -435,10 +452,7 @@ int writeindividualtimes(struct dquot *qlist, int outfd, char *name, int quotaty
time_t now;
char btimestr[MAXTIMELEN], itimestr[MAXTIMELEN];
- ftruncate(outfd, 0);
- lseek(outfd, 0, SEEK_SET);
- if (!(fd = fdopen(dup(outfd), "w")))
- die(1, _("Cannot duplicate descriptor of file to write to: %s\n"), strerror(errno));
+ fd = dup_file(outfd, 1);
fprintf(fd, _("Times to enforce softlimit for %s %s (%cid %d):\n"),
_(type2name(quotatype)), name, *type2name(quotatype), qlist->dq_id);
@@ -478,9 +492,7 @@ int readindividualtimes(struct dquot *qlist, int infd)
char iunits[BUFSIZ], bunits[BUFSIZ];
time_t now, bseconds, iseconds;
- lseek(infd, 0, SEEK_SET);
- if (!(fd = fdopen(dup(infd), "r")))
- die(1, _("Cannot duplicate descriptor of temp file: %s\n"), strerror(errno));
+ fd = dup_file(infd, 0);
/*
* Discard title lines, then read lines to process.
@@ -543,10 +555,7 @@ int writetimes(struct quota_handle **handles, int outfd)
if (!handles[0])
return 0;
- ftruncate(outfd, 0);
- lseek(outfd, 0, SEEK_SET);
- if ((fd = fdopen(dup(outfd), "w")) == NULL)
- die(1, _("Cannot duplicate descriptor of file to edit: %s\n"), strerror(errno));
+ fd = dup_file(outfd, 1);
fprintf(fd, _("Grace period before enforcing soft limits for %ss:\n"),
_(type2name(handles[0]->qh_type)));
@@ -575,12 +584,8 @@ int readtimes(struct quota_handle **handles, int infd)
if (!handles[0])
return 0;
- lseek(infd, 0, SEEK_SET);
- if (!(fd = fdopen(dup(infd), "r"))) {
- errstr(_("Cannot reopen temp file: %s\n"),
- strerror(errno));
- return -1;
- }
+
+ fd = dup_file(infd, 0);
/* Set all grace times to default values */
for (i = 0; handles[i]; i++) {
--
2.9.4