In interfaces of ioctl, mnt_{want,drop}_write_file should be used for:
- get exclusion against file system freezing which may used by lvm
snapshot.
- do telling filesystem that a write is about to be performed on it, and
make sure that the writes are permitted.
Signed-off-by: Chao Yu <yuch...@huawei.com>
---
fs/f2fs/file.c | 130 ++++++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 97 insertions(+), 33 deletions(-)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index d5910bc..828b53e 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1374,20 +1374,16 @@ static int f2fs_ioc_setflags(struct file *filp,
unsigned long arg)
unsigned int oldflags;
int ret;
+ if (!inode_owner_or_capable(inode))
+ return -EACCES;
+
+ if (get_user(flags, (int __user *)arg))
+ return -EFAULT;
+
ret = mnt_want_write_file(filp);
if (ret)
return ret;
- if (!inode_owner_or_capable(inode)) {
- ret = -EACCES;
- goto out;
- }
-
- if (get_user(flags, (int __user *)arg)) {
- ret = -EFAULT;
- goto out;
- }
-
flags = f2fs_mask_flags(inode->i_mode, flags);
inode_lock(inode);
@@ -1430,18 +1426,22 @@ static int f2fs_ioc_start_atomic_write(struct file
*filp)
if (!inode_owner_or_capable(inode))
return -EACCES;
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
if (f2fs_is_atomic_file(inode))
- return 0;
+ goto out;
ret = f2fs_convert_inline_inode(inode);
if (ret)
- return ret;
+ goto out;
set_inode_flag(F2FS_I(inode), FI_ATOMIC_FILE);
f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
if (!get_dirty_pages(inode))
- return 0;
+ goto out;
f2fs_msg(F2FS_I_SB(inode)->sb, KERN_WARNING,
"Unexpected flush for atomic writes: ino=%lu, npages=%u",
@@ -1449,6 +1449,8 @@ static int f2fs_ioc_start_atomic_write(struct file *filp)
ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
if (ret)
clear_inode_flag(F2FS_I(inode), FI_ATOMIC_FILE);
+out:
+ mnt_drop_write_file(filp);
return ret;
}
@@ -1460,13 +1462,13 @@ static int f2fs_ioc_commit_atomic_write(struct file
*filp)
if (!inode_owner_or_capable(inode))
return -EACCES;
- if (f2fs_is_volatile_file(inode))
- return 0;
-
ret = mnt_want_write_file(filp);
if (ret)
return ret;
+ if (f2fs_is_volatile_file(inode))
+ goto err_out;
+
if (f2fs_is_atomic_file(inode)) {
clear_inode_flag(F2FS_I(inode), FI_ATOMIC_FILE);
ret = commit_inmem_pages(inode);
@@ -1490,32 +1492,48 @@ static int f2fs_ioc_start_volatile_write(struct file
*filp)
if (!inode_owner_or_capable(inode))
return -EACCES;
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
if (f2fs_is_volatile_file(inode))
- return 0;
+ goto out;
ret = f2fs_convert_inline_inode(inode);
if (ret)
- return ret;
+ goto out;
set_inode_flag(F2FS_I(inode), FI_VOLATILE_FILE);
f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
- return 0;
+out:
+ mnt_drop_write_file(filp);
+ return ret;
}
static int f2fs_ioc_release_volatile_write(struct file *filp)
{
struct inode *inode = file_inode(filp);
+ int ret;
if (!inode_owner_or_capable(inode))
return -EACCES;
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
if (!f2fs_is_volatile_file(inode))
- return 0;
+ goto out;
- if (!f2fs_is_first_block_written(inode))
- return truncate_partial_data_page(inode, 0, true);
+ if (!f2fs_is_first_block_written(inode)) {
+ ret = truncate_partial_data_page(inode, 0, true);
+ goto out;
+ }
- return punch_hole(inode, 0, F2FS_BLKSIZE);
+ ret = punch_hole(inode, 0, F2FS_BLKSIZE);
+out:
+ mnt_drop_write_file(filp);
+ return ret;
}
static int f2fs_ioc_abort_volatile_write(struct file *filp)
@@ -1548,6 +1566,7 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned
long arg)
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
struct super_block *sb = sbi->sb;
__u32 in;
+ int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@@ -1555,6 +1574,10 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned
long arg)
if (get_user(in, (__u32 __user *)arg))
return -EFAULT;
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
switch (in) {
case F2FS_GOING_DOWN_FULLSYNC:
sb = freeze_bdev(sb->s_bdev);
@@ -1576,10 +1599,13 @@ static int f2fs_ioc_shutdown(struct file *filp,
unsigned long arg)
f2fs_stop_checkpoint(sbi);
break;
default:
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
f2fs_update_time(sbi, REQ_TIME);
- return 0;
+out:
+ mnt_drop_write_file(filp);
+ return ret;
}
static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
@@ -1600,9 +1626,14 @@ static int f2fs_ioc_fitrim(struct file *filp, unsigned
long arg)
sizeof(range)))
return -EFAULT;
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
range.minlen = max((unsigned int)range.minlen,
q->limits.discard_granularity);
ret = f2fs_trim_fs(F2FS_SB(sb), &range);
+ mnt_drop_write_file(filp);
if (ret < 0)
return ret;
@@ -1629,6 +1660,7 @@ static int f2fs_ioc_keyctl(struct file *filp, unsigned
long arg)
struct f2fs_key key;
void *value = key.key;
int type = XATTR_CREATE;
+ int ret;
if (copy_from_user(&key, (u8 __user *)arg, sizeof(key)))
return -EFAULT;
@@ -1636,33 +1668,47 @@ static int f2fs_ioc_keyctl(struct file *filp, unsigned
long arg)
if (!S_ISREG(inode->i_mode))
return -EINVAL;
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
if (key.mode == F2FS_DROP_KEY) {
int ret = validate_access_key(inode);
-
if (ret)
- return ret;
+ goto out;
value = NULL;
type = XATTR_REPLACE;
}
f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
- return f2fs_setxattr(inode, F2FS_XATTR_INDEX_KEY,
+ ret = f2fs_setxattr(inode, F2FS_XATTR_INDEX_KEY,
F2FS_XATTR_NAME_ENCRYPTION_CONTEXT,
value, F2FS_KEY_SIZE, NULL, type);
+out:
+ mnt_drop_write_file(filp);
+ return ret;
}
static int f2fs_ioc_set_encryption_policy(struct file *filp, unsigned long arg)
{
struct fscrypt_policy policy;
struct inode *inode = file_inode(filp);
+ int ret;
if (copy_from_user(&policy, (struct fscrypt_policy __user *)arg,
sizeof(policy)))
return -EFAULT;
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
- return fscrypt_process_policy(inode, &policy);
+ ret = fscrypt_process_policy(inode, &policy);
+
+ mnt_drop_write_file(filp);
+ return ret;
}
static int f2fs_ioc_get_encryption_policy(struct file *filp, unsigned long arg)
@@ -1719,6 +1765,7 @@ static int f2fs_ioc_gc(struct file *filp, unsigned long
arg)
struct inode *inode = file_inode(filp);
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
__u32 sync;
+ int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@@ -1729,20 +1776,30 @@ static int f2fs_ioc_gc(struct file *filp, unsigned long
arg)
if (f2fs_readonly(sbi->sb))
return -EROFS;
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
if (!sync) {
- if (!mutex_trylock(&sbi->gc_mutex))
- return -EBUSY;
+ if (!mutex_trylock(&sbi->gc_mutex)) {
+ ret = -EBUSY;
+ goto out;
+ }
} else {
mutex_lock(&sbi->gc_mutex);
}
- return f2fs_gc(sbi, sync);
+ ret = f2fs_gc(sbi, sync);
+out:
+ mnt_drop_write_file(filp);
+ return ret;
}
static int f2fs_ioc_write_checkpoint(struct file *filp, unsigned long arg)
{
struct inode *inode = file_inode(filp);
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@@ -1750,7 +1807,14 @@ static int f2fs_ioc_write_checkpoint(struct file *filp,
unsigned long arg)
if (f2fs_readonly(sbi->sb))
return -EROFS;
- return f2fs_sync_fs(sbi->sb, 1);
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
+ ret = f2fs_sync_fs(sbi->sb, 1);
+
+ mnt_drop_write_file(filp);
+ return ret;
}
static int f2fs_defragment_range(struct f2fs_sb_info *sbi,
--
2.8.2.311.gee88674
