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ANDROID: Incremental fs: get_filled_blocks: better index_out

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When returning incomplete results index_out has to be usable to
call the function again and resume from the same location. This
means that if the output buffer was too small the function needs
to check for that when encountering the _beginning_ of a next
output range, not the end of it. Otherwise resuming from the
end of the range that didn't fit into the buffer would cause
the call to never return that range

+ Make the backing file header flags update thread safe

Bug: 152691988
Test: libincfs-test, incfs_test passes
Signed-off-by: Yurii Zubrytskyi <zyy@google.com>
Change-Id: I351156beba0b74e1942a39117279d3fcdb5e0c78
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Git-commit: 21b6d8c954
Git-repo: https://android.googlesource.com/kernel/common/
Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
This commit is contained in:
Yurii Zubrytskyi
2020-03-29 14:13:32 -07:00
committed by Blagovest Kolenichev
parent 3e5ba8c19e
commit cbad8026de
3 changed files with 61 additions and 12 deletions
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69
fs/incfs/data_mgmt.c
View File

@@ -371,11 +371,19 @@ static int get_data_file_block(struct data_file *df, int index,
return 0;
}
static int check_room_for_one_range(u32 size, u32 size_out)
{
if (size_out + sizeof(struct incfs_filled_range) > size)
return -ERANGE;
return 0;
}
static int copy_one_range(struct incfs_filled_range *range, void __user *buffer,
u32 size, u32 *size_out)
{
if (*size_out + sizeof(*range) > size)
return -ERANGE;
int error = check_room_for_one_range(size, *size_out);
if (error)
return error;
if (copy_to_user(((char *)buffer) + *size_out, range, sizeof(*range)))
return -EFAULT;
@@ -384,6 +392,34 @@ static int copy_one_range(struct incfs_filled_range *range, void __user *buffer,
return 0;
}
static int update_file_header_flags(struct data_file *df, u32 bits_to_reset,
u32 bits_to_set)
{
int result;
u32 new_flags;
struct backing_file_context *bfc;
if (!df)
return -EFAULT;
bfc = df->df_backing_file_context;
if (!bfc)
return -EFAULT;
result = mutex_lock_interruptible(&bfc->bc_mutex);
if (result)
return result;
new_flags = (df->df_header_flags & ~bits_to_reset) | bits_to_set;
if (new_flags != df->df_header_flags) {
df->df_header_flags = new_flags;
result = incfs_write_file_header_flags(bfc, new_flags);
}
mutex_unlock(&bfc->bc_mutex);
return result;
}
int incfs_get_filled_blocks(struct data_file *df,
struct incfs_get_filled_blocks_args *arg)
{
@@ -407,14 +443,22 @@ int incfs_get_filled_blocks(struct data_file *df,
arg->index_out = arg->start_index;
return 0;
}
arg->index_out = arg->start_index;
error = check_room_for_one_range(size, *size_out);
if (error)
return error;
range = (struct incfs_filled_range){
.begin = arg->start_index,
.end = end_index,
};
error = copy_one_range(&range, buffer, size, size_out);
if (error)
return error;
arg->index_out = end_index;
return copy_one_range(&range, buffer, size, size_out);
return 0;
}
for (arg->index_out = arg->start_index; arg->index_out < end_index;
@@ -429,13 +473,20 @@ int incfs_get_filled_blocks(struct data_file *df,
continue;
if (!in_range) {
error = check_room_for_one_range(size, *size_out);
if (error)
break;
in_range = true;
range.begin = arg->index_out;
} else {
range.end = arg->index_out;
error = copy_one_range(&range, buffer, size, size_out);
if (error)
if (error) {
/* there will be another try out of the loop,
* it will reset the index_out if it fails too
*/
break;
}
in_range = false;
}
}
@@ -443,17 +494,15 @@ int incfs_get_filled_blocks(struct data_file *df,
if (in_range) {
range.end = arg->index_out;
error = copy_one_range(&range, buffer, size, size_out);
if (error)
arg->index_out = range.begin;
}
if (!error && in_range && arg->start_index == 0 &&
end_index == df->df_total_block_count &&
*size_out == sizeof(struct incfs_filled_range)) {
int result;
df->df_header_flags |= INCFS_FILE_COMPLETE;
result = incfs_update_file_header_flags(
df->df_backing_file_context, df->df_header_flags);
int result =
update_file_header_flags(df, 0, INCFS_FILE_COMPLETE);
/* Log failure only, since it's just a failed optimization */
pr_debug("Marked file full with result %d", result);
}