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fs: use must_set_pos()

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Make generic_file_llseek_size() use must_set_pos(). We'll use
must_set_pos() in another helper in a minutes. Remove __maybe_unused
from must_set_pos() now that it's used.

Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-7-6d3e4816aa7b@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2024-08-30 15:04:48 +02:00
parent b8c7451928
commit ed904935c3
No known key found for this signature in database
GPG key ID: 91C61BC06578DCA2
1 changed files with 14 additions and 38 deletions
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52
fs/read_write.c
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@ -98,8 +98,7 @@ EXPORT_SYMBOL(vfs_setpos);
* Return: 0 if f_pos doesn't need to be updated, 1 if f_pos has to be
* updated, and negative error code on failure.
*/
static __maybe_unused int must_set_pos(struct file *file, loff_t *offset,
int whence, loff_t eof)
static int must_set_pos(struct file *file, loff_t *offset, int whence, loff_t eof)
{
switch (whence) {
case SEEK_END:
@ -159,45 +158,22 @@ loff_t
generic_file_llseek_size(struct file *file, loff_t offset, int whence,
loff_t maxsize, loff_t eof)
{
switch (whence) {
case SEEK_END:
offset += eof;
break;
case SEEK_CUR:
/*
* Here we special-case the lseek(fd, 0, SEEK_CUR)
* position-querying operation. Avoid rewriting the "same"
* f_pos value back to the file because a concurrent read(),
* write() or lseek() might have altered it
*/
if (offset == 0)
return file->f_pos;
/*
* f_lock protects against read/modify/write race with other
* SEEK_CURs. Note that parallel writes and reads behave
* like SEEK_SET.
*/
spin_lock(&file->f_lock);
offset = vfs_setpos(file, file->f_pos + offset, maxsize);
spin_unlock(&file->f_lock);
int ret;
ret = must_set_pos(file, &offset, whence, eof);
if (ret < 0)
return ret;
if (ret == 0)
return offset;
case SEEK_DATA:
if (whence == SEEK_CUR) {
/*
* In the generic case the entire file is data, so as long as
* offset isn't at the end of the file then the offset is data.
* f_lock protects against read/modify/write race with
* other SEEK_CURs. Note that parallel writes and reads
* behave like SEEK_SET.
*/
if ((unsigned long long)offset >= eof)
return -ENXIO;
break;
case SEEK_HOLE:
/*
* There is a virtual hole at the end of the file, so as long as
* offset isn't i_size or larger, return i_size.
*/
if ((unsigned long long)offset >= eof)
return -ENXIO;
offset = eof;
break;
guard(spinlock)(&file->f_lock);
return vfs_setpos(file, file->f_pos + offset, maxsize);
}
return vfs_setpos(file, offset, maxsize);