libext2fs: don't use O_DIRECT for files on tmpfs

[thirdparty/e2fsprogs.git] / lib / ext2fs / mmp.c

diff --git a/lib/ext2fs/mmp.c b/lib/ext2fs/mmp.c
index 12bfc0f4257b5dcaf3050bf3ea9dee72d228f95f..e96a227327fcaa691d3aa9fe5d8eaef26bb8d999 100644 (file)
--- a/lib/ext2fs/mmp.c
+++ b/lib/ext2fs/mmp.c
@@ -12,6 +12,9 @@
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
 #endif
+#ifndef _DEFAULT_SOURCE
+#define _DEFAULT_SOURCE        /* since glibc 2.20 _SVID_SOURCE is deprecated */
+#endif
 
 #include "config.h"
 
@@ -31,6 +34,13 @@
 #define O_DIRECT 0
 #endif
 
+#if __GNUC_PREREQ (4, 6)
+#pragma GCC diagnostic push
+#ifndef CONFIG_MMP
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+#endif
+#endif
+
 errcode_t ext2fs_mmp_read(ext2_filsys fs, blk64_t mmp_blk, void *buf)
 {
 #ifdef CONFIG_MMP
@@ -47,8 +57,21 @@ errcode_t ext2fs_mmp_read(ext2_filsys fs, blk64_t mmp_blk, void *buf)
         * regardless of how the io_manager is doing reads, to avoid caching of
         * the MMP block by the io_manager or the VM.  It needs to be fresh. */
        if (fs->mmp_fd <= 0) {
-               fs->mmp_fd = open(fs->device_name, O_RDWR | O_DIRECT);
+               int flags = O_RDWR | O_DIRECT;
+
+retry:
+               fs->mmp_fd = open(fs->device_name, flags);
                if (fs->mmp_fd < 0) {
+                       struct stat st;
+
+                       /* Avoid O_DIRECT for filesystem image files if open
+                        * fails, since it breaks when running on tmpfs. */
+                       if (errno == EINVAL && (flags & O_DIRECT) &&
+                           stat(fs->device_name, &st) == 0 &&
+                           S_ISREG(st.st_mode)) {
+                               flags &= ~O_DIRECT;
+                               goto retry;
+                       }
                        retval = EXT2_ET_MMP_OPEN_DIRECT;
                        goto out;
                }
@@ -144,7 +167,7 @@ errcode_t ext2fs_mmp_write(ext2_filsys fs, blk64_t mmp_blk, void *buf)
 #define rand()         random()
 #endif
 
-unsigned ext2fs_mmp_new_seq()
+unsigned ext2fs_mmp_new_seq(void)
 {
 #ifdef CONFIG_MMP
        unsigned new_seq;
@@ -168,6 +191,7 @@ unsigned ext2fs_mmp_new_seq()
 #endif
 }
 
+#ifdef CONFIG_MMP
 static errcode_t ext2fs_mmp_reset(ext2_filsys fs)
 {
        struct mmp_struct *mmp_s = NULL;
@@ -185,7 +209,7 @@ static errcode_t ext2fs_mmp_reset(ext2_filsys fs)
        mmp_s->mmp_magic = EXT4_MMP_MAGIC;
        mmp_s->mmp_seq = EXT4_MMP_SEQ_CLEAN;
        mmp_s->mmp_time = 0;
-#if _BSD_SOURCE || _XOPEN_SOURCE >= 500
+#ifdef HAVE_GETHOSTNAME
        gethostname(mmp_s->mmp_nodename, sizeof(mmp_s->mmp_nodename));
 #else
        mmp_s->mmp_nodename[0] = '\0';
@@ -201,6 +225,7 @@ static errcode_t ext2fs_mmp_reset(ext2_filsys fs)
 out:
        return retval;
 }
+#endif
 
 errcode_t ext2fs_mmp_update(ext2_filsys fs)
 {
@@ -259,6 +284,10 @@ out:
 #endif
 }
 
+#ifndef min
+#define min(x, y) ((x) < (y) ? (x) : (y))
+#endif
+
 /*
  * Make sure that the fs is not mounted or being fsck'ed while opening the fs.
  */
@@ -306,7 +335,7 @@ errcode_t ext2fs_mmp_start(ext2_filsys fs)
        if (mmp_s->mmp_check_interval > mmp_check_interval)
                mmp_check_interval = mmp_s->mmp_check_interval;
 
-       sleep(2 * mmp_check_interval + 1);
+       sleep(min(mmp_check_interval * 2 + 1, mmp_check_interval + 60));
 
        retval = ext2fs_mmp_read(fs, fs->super->s_mmp_block, fs->mmp_buf);
        if (retval)
@@ -322,7 +351,7 @@ clean_seq:
                goto mmp_error;
 
        mmp_s->mmp_seq = seq = ext2fs_mmp_new_seq();
-#if _BSD_SOURCE || _XOPEN_SOURCE >= 500
+#ifdef HAVE_GETHOSTNAME
        gethostname(mmp_s->mmp_nodename, sizeof(mmp_s->mmp_nodename));
 #else
        strcpy(mmp_s->mmp_nodename, "unknown host");
@@ -334,7 +363,7 @@ clean_seq:
        if (retval)
                goto mmp_error;
 
-       sleep(2 * mmp_check_interval + 1);
+       sleep(min(2 * mmp_check_interval + 1, mmp_check_interval + 60));
 
        retval = ext2fs_mmp_read(fs, fs->super->s_mmp_block, fs->mmp_buf);
        if (retval)
@@ -371,7 +400,7 @@ errcode_t ext2fs_mmp_stop(ext2_filsys fs)
        struct mmp_struct *mmp, *mmp_cmp;
        errcode_t retval = 0;
 
-       if (!(fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_MMP) ||
+       if (!ext2fs_has_feature_mmp(fs->super) ||
            !(fs->flags & EXT2_FLAG_RW) || (fs->flags & EXT2_FLAG_SKIP_MMP))
                goto mmp_error;
 
@@ -398,6 +427,10 @@ mmp_error:
 
        return retval;
 #else
+       if (!ext2fs_has_feature_mmp(fs->super) ||
+           !(fs->flags & EXT2_FLAG_RW) || (fs->flags & EXT2_FLAG_SKIP_MMP))
+               return 0;
+
        return EXT2_ET_OP_NOT_SUPPORTED;
 #endif
 }
@@ -414,7 +447,7 @@ errcode_t ext2fs_mmp_update2(ext2_filsys fs, int immediately)
        struct timeval tv;
        errcode_t retval = 0;
 
-       if (!(fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_MMP) ||
+       if (!ext2fs_has_feature_mmp(fs->super) ||
            !(fs->flags & EXT2_FLAG_RW) || (fs->flags & EXT2_FLAG_SKIP_MMP))
                return 0;
 
@@ -440,6 +473,13 @@ errcode_t ext2fs_mmp_update2(ext2_filsys fs, int immediately)
 mmp_error:
        return retval;
 #else
+       if (!ext2fs_has_feature_mmp(fs->super) ||
+           !(fs->flags & EXT2_FLAG_RW) || (fs->flags & EXT2_FLAG_SKIP_MMP))
+               return 0;
+
        return EXT2_ET_OP_NOT_SUPPORTED;
 #endif
 }
+#if __GNUC_PREREQ (4, 6)
+#pragma GCC diagnostic pop
+#endif