ref: 8929c98e42e81dce0b00d03a1c7b2f45ee85fe87
parent: 9b40d089d6cf5912b558dd3e0ca1a246baa6750a
author: ngkaho1234 <ngkaho1234@gmail.com>
date: Sat Jan 30 18:26:22 EST 2016
ext4: add read_only parameter to ext4_mount routine. Now users can mount a filesystem as read-only mode explicitly.
--- a/fs_test/common/test_lwext4.c
+++ b/fs_test/common/test_lwext4.c
@@ -336,7 +336,7 @@
return false;
}
- r = ext4_mount("ext4_fs", "/mp/");+ r = ext4_mount("ext4_fs", "/mp/", false); if (r != EOK) { printf("ext4_mount: rc = %d\n", r);return false;
--- a/fs_test/lwext4_server.c
+++ b/fs_test/lwext4_server.c
@@ -419,7 +419,7 @@
if (verbose)
ext4_dmask_set(DEBUG_ALL);
- rc = ext4_mount(dev_name, mount_point);
+ rc = ext4_mount(dev_name, mount_point, false);
if (rc != EOK)
return rc;
--- a/include/ext4.h
+++ b/include/ext4.h
@@ -122,9 +122,12 @@
* - /
* - /my_partition/
* - /my_second_partition/
+ * @param read_only mount as read-only mode.
*
* @return standard error code */
-int ext4_mount(const char *dev_name, const char *mount_point);
+int ext4_mount(const char *dev_name,
+ const char *mount_point,
+ bool read_only);
/**@brief Umount operation.
* @param mount_point mount name
--- a/include/ext4_fs.h
+++ b/include/ext4_fs.h
@@ -93,9 +93,11 @@
/**@brief Initialize filesystem and read all needed data.
* @param fs Filesystem instance to be initialized
* @param bdev Identifier if device with the filesystem
+ * @param read_only Mark the filesystem as read-only.
* @return Error code
*/
-int ext4_fs_init(struct ext4_fs *fs, struct ext4_blockdev *bdev);
+int ext4_fs_init(struct ext4_fs *fs, struct ext4_blockdev *bdev,
+ bool read_only);
/**@brief Destroy filesystem instance (used by unmount operation).
* @param fs Filesystem to be destroyed
--- a/include/ext4_types.h
+++ b/include/ext4_types.h
@@ -303,6 +303,8 @@
#endif
struct ext4_fs {+ bool read_only;
+
struct ext4_blockdev *bdev;
struct ext4_sblock sb;
--- a/src/ext4.c
+++ b/src/ext4.c
@@ -329,7 +329,8 @@
/****************************************************************************/
-int ext4_mount(const char *dev_name, const char *mount_point)
+int ext4_mount(const char *dev_name, const char *mount_point,
+ bool read_only)
{ext4_assert(mount_point && dev_name);
int r;
@@ -375,7 +376,7 @@
if (r != EOK)
return r;
- r = ext4_fs_init(&mp->fs, bd);
+ r = ext4_fs_init(&mp->fs, bd, read_only);
if (r != EOK) {ext4_block_fini(bd);
return r;
@@ -475,6 +476,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EOK;
+
if (ext4_sb_feature_com(&mp->fs.sb,
EXT4_FCOM_HAS_JOURNAL)) {r = jbd_get_fs(&mp->fs, &mp->jbd_fs);
@@ -502,6 +506,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EOK;
+
if (ext4_sb_feature_com(&mp->fs.sb,
EXT4_FCOM_HAS_JOURNAL)) {r = jbd_journal_stop(&mp->jbd_journal);
@@ -893,6 +900,9 @@
struct ext4_fs *const fs = &mp->fs;
struct ext4_sblock *const sb = &mp->fs.sb;
+ if (fs->read_only && flags & O_CREAT)
+ return EROFS;
+
f->flags = flags;
/*Skip mount point*/
@@ -1218,6 +1228,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EROFS;
+
/* Will that happen? Anyway return EINVAL for such case. */
if (mp != target_mp)
return EINVAL;
@@ -1276,6 +1289,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EROFS;
+
EXT4_MP_LOCK(mp);
ext4_trans_start(mp);
@@ -1367,6 +1383,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EROFS;
+
EXT4_MP_LOCK(mp);
ext4_trans_start(mp);
@@ -1590,6 +1609,9 @@
int r;
ext4_assert(f && f->mp);
+ if (f->mp->fs.read_only)
+ return EROFS;
+
if (f->flags & O_RDONLY)
return EPERM;
@@ -1623,6 +1645,9 @@
ext4_assert(f && f->mp);
+ if (f->mp->fs.read_only)
+ return EROFS;
+
if (f->flags & O_WRONLY)
return EPERM;
@@ -1783,6 +1808,9 @@
ext4_assert(f && f->mp);
+ if (f->mp->fs.read_only)
+ return EROFS;
+
if (f->flags & O_RDONLY)
return EPERM;
@@ -1998,6 +2026,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EROFS;
+
EXT4_MP_LOCK(mp);
ext4_trans_start(mp);
@@ -2044,6 +2075,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EROFS;
+
EXT4_MP_LOCK(mp);
ext4_trans_start(mp);
@@ -2087,6 +2121,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EROFS;
+
EXT4_MP_LOCK(mp);
ext4_trans_start(mp);
@@ -2129,6 +2166,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EROFS;
+
EXT4_MP_LOCK(mp);
ext4_trans_start(mp);
@@ -2171,6 +2211,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EROFS;
+
EXT4_MP_LOCK(mp);
ext4_trans_start(mp);
@@ -2279,6 +2322,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EROFS;
+
filetype = EXT4_DE_SYMLINK;
EXT4_MP_LOCK(mp);
@@ -2356,6 +2402,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EROFS;
+
dissected_name = ext4_extract_xattr_name(name, name_len,
&name_index, &dissected_len);
if (!dissected_len)
@@ -2545,6 +2594,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EROFS;
+
dissected_name = ext4_extract_xattr_name(name, name_len,
&name_index, &dissected_len);
if (!dissected_len)
@@ -2610,6 +2662,9 @@
if (!mp)
return ENOENT;
+ if (mp->fs.read_only)
+ return EROFS;
+
EXT4_MP_LOCK(mp);
struct ext4_fs *const fs = &mp->fs;
@@ -2837,6 +2892,9 @@
if (!mp)
return ENOENT;
+
+ if (mp->fs.read_only)
+ return EROFS;
EXT4_MP_LOCK(mp);
ext4_trans_start(mp);
--- a/src/ext4_fs.c
+++ b/src/ext4_fs.c
@@ -55,12 +55,12 @@
#include <string.h>
-int ext4_fs_init(struct ext4_fs *fs, struct ext4_blockdev *bdev)
+int ext4_fs_init(struct ext4_fs *fs, struct ext4_blockdev *bdev,
+ bool read_only)
{int r, i;
uint16_t tmp;
uint32_t bsize;
- bool read_only = false;
ext4_assert(fs && bdev);
@@ -82,7 +82,7 @@
return r;
if (read_only)
- return ENOTSUP;
+ fs->read_only = true;
/* Compute limits for indirect block levels */
uint32_t blocks_id = bsize / sizeof(uint32_t);
@@ -104,14 +104,16 @@
"last umount error: superblock fs_error flag\n");
- /* Mark system as mounted */
- ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_ERROR_FS);
- r = ext4_sb_write(fs->bdev, &fs->sb);
- if (r != EOK)
- return r;
+ if (!fs->read_only) {+ /* Mark system as mounted */
+ ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_ERROR_FS);
+ r = ext4_sb_write(fs->bdev, &fs->sb);
+ if (r != EOK)
+ return r;
- /*Update mount count*/
- ext4_set16(&fs->sb, mount_count, ext4_get16(&fs->sb, mount_count) + 1);
+ /*Update mount count*/
+ ext4_set16(&fs->sb, mount_count, ext4_get16(&fs->sb, mount_count) + 1);
+ }
return r;
}
@@ -123,7 +125,10 @@
/*Set superblock state*/
ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_VALID_FS);
- return ext4_sb_write(fs->bdev, &fs->sb);
+ if (!fs->read_only)
+ return ext4_sb_write(fs->bdev, &fs->sb);
+
+ return EOK;
}
static void ext4_fs_debug_features_inc(uint32_t features_incompatible)
--- a/src/ext4_mkfs.c
+++ b/src/ext4_mkfs.c
@@ -740,7 +740,7 @@
if (r != EOK)
goto cache_fini;
- r = ext4_fs_init(fs, bd);
+ r = ext4_fs_init(fs, bd, false);
if (r != EOK)
goto cache_fini;