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authorDavid Howells <dhowells@redhat.com>2024-01-02 16:28:04 +0000
committerDavid Howells <dhowells@redhat.com>2024-01-03 14:52:53 +0000
commit7097c96411d22a1b3f6370dfd7eb2e3b7b83ff98 (patch)
tree71487edab7c0bb7bf522bbac7b6df7ab94d5bded
parent80105ed2fd2715fb09a8fdb0655a8bdc86c120db (diff)
cachefiles: Fix __cachefiles_prepare_write()
Fix __cachefiles_prepare_write() to correctly determine whether the requested write will fit correctly with the DIO alignment. Reported-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Yiqun Leng <yqleng@linux.alibaba.com> Tested-by: Jia Zhu <zhujia.zj@bytedance.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com cc: linux-erofs@lists.ozlabs.org cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org
-rw-r--r--fs/cachefiles/io.c28
1 files changed, 17 insertions, 11 deletions
diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c
index bffffedce4a9..7529b40bc95a 100644
--- a/fs/cachefiles/io.c
+++ b/fs/cachefiles/io.c
@@ -522,16 +522,22 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
bool no_space_allocated_yet)
{
struct cachefiles_cache *cache = object->volume->cache;
- loff_t start = *_start, pos;
- size_t len = *_len, down;
+ unsigned long long start = *_start, pos;
+ size_t len = *_len;
int ret;
/* Round to DIO size */
- down = start - round_down(start, PAGE_SIZE);
- *_start = start - down;
- *_len = round_up(down + len, PAGE_SIZE);
- if (down < start || *_len > upper_len)
+ start = round_down(*_start, PAGE_SIZE);
+ if (start != *_start) {
+ kleave(" = -ENOBUFS [down]");
+ return -ENOBUFS;
+ }
+ if (*_len > upper_len) {
+ kleave(" = -ENOBUFS [up]");
return -ENOBUFS;
+ }
+
+ *_len = round_up(len, PAGE_SIZE);
/* We need to work out whether there's sufficient disk space to perform
* the write - but we can skip that check if we have space already
@@ -542,7 +548,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
pos = cachefiles_inject_read_error();
if (pos == 0)
- pos = vfs_llseek(file, *_start, SEEK_DATA);
+ pos = vfs_llseek(file, start, SEEK_DATA);
if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) {
if (pos == -ENXIO)
goto check_space; /* Unallocated tail */
@@ -550,7 +556,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
cachefiles_trace_seek_error);
return pos;
}
- if ((u64)pos >= (u64)*_start + *_len)
+ if (pos >= start + *_len)
goto check_space; /* Unallocated region */
/* We have a block that's at least partially filled - if we're low on
@@ -563,13 +569,13 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
pos = cachefiles_inject_read_error();
if (pos == 0)
- pos = vfs_llseek(file, *_start, SEEK_HOLE);
+ pos = vfs_llseek(file, start, SEEK_HOLE);
if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) {
trace_cachefiles_io_error(object, file_inode(file), pos,
cachefiles_trace_seek_error);
return pos;
}
- if ((u64)pos >= (u64)*_start + *_len)
+ if (pos >= start + *_len)
return 0; /* Fully allocated */
/* Partially allocated, but insufficient space: cull. */
@@ -577,7 +583,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
ret = cachefiles_inject_remove_error();
if (ret == 0)
ret = vfs_fallocate(file, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
- *_start, *_len);
+ start, *_len);
if (ret < 0) {
trace_cachefiles_io_error(object, file_inode(file), ret,
cachefiles_trace_fallocate_error);