diff options
| author | Omar Sandoval <osandov@fb.com> | 2021-08-12 15:34:57 -0700 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2022-03-14 13:13:50 +0100 |
| commit | f6f7a25a650818c61defa97d60a79b216618315f (patch) | |
| tree | 9e347008104e54d5ab694e8dc0e941d54ff852fc | |
| parent | 871129332d74c9e94bd110932ac4445833995639 (diff) | |
| download | linux-f6f7a25a650818c61defa97d60a79b216618315f.tar.bz2 | |
fs: export variant of generic_write_checks without iov_iter
Encoded I/O in Btrfs needs to check a write with a given logical size
without an iov_iter that matches that size (because the iov_iter we have
is for the compressed data). So, factor out the parts of
generic_write_check() that don't need an iov_iter into a new
generic_write_checks_count() function and export that.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
| -rw-r--r-- | fs/read_write.c | 33 | ||||
| -rw-r--r-- | include/linux/fs.h | 1 |
2 files changed, 21 insertions, 13 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index 4d60146243df..dc5000173b80 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1618,24 +1618,16 @@ int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count) return 0; } -/* - * Performs necessary checks before doing a write - * - * Can adjust writing position or amount of bytes to write. - * Returns appropriate error code that caller should return or - * zero in case that write should be allowed. - */ -ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) +/* Like generic_write_checks(), but takes size of write instead of iter. */ +int generic_write_checks_count(struct kiocb *iocb, loff_t *count) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; - loff_t count; - int ret; if (IS_SWAPFILE(inode)) return -ETXTBSY; - if (!iov_iter_count(from)) + if (!*count) return 0; /* FIXME: this is for backwards compatibility with 2.4 */ @@ -1645,8 +1637,23 @@ ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)) return -EINVAL; - count = iov_iter_count(from); - ret = generic_write_check_limits(file, iocb->ki_pos, &count); + return generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, count); +} +EXPORT_SYMBOL(generic_write_checks_count); + +/* + * Performs necessary checks before doing a write + * + * Can adjust writing position or amount of bytes to write. + * Returns appropriate error code that caller should return or + * zero in case that write should be allowed. + */ +ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) +{ + loff_t count = iov_iter_count(from); + int ret; + + ret = generic_write_checks_count(iocb, &count); if (ret) return ret; diff --git a/include/linux/fs.h b/include/linux/fs.h index 0ebfc2519212..27746a3da8fd 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3130,6 +3130,7 @@ extern int sb_min_blocksize(struct super_block *, int); extern int generic_file_mmap(struct file *, struct vm_area_struct *); extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *); extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *); +int generic_write_checks_count(struct kiocb *iocb, loff_t *count); extern int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count); extern int generic_file_rw_checks(struct file *file_in, struct file *file_out); |