From: Amir Goldstein <amir73il@gmail.com> mainline inclusion from mainline-v6.8-rc1 commit 21b32e6a0ab5b174fa1ca2fb4c212577cf405d83 category: feature bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBHLU4 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Create new helpers {sb,file}_write_not_started() that can be used to assert that sb_start_write() is not held. This is needed for fanotify "pre content" events. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20231122122715.2561213-17-amir73il@gmail.com Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> --- include/linux/fs.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/include/linux/fs.h b/include/linux/fs.h index f0a2c5861cd5..e6e5d30bb424 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1714,6 +1714,17 @@ static inline bool sb_write_started(const struct super_block *sb) return __sb_write_started(sb, SB_FREEZE_WRITE); } +/** + * sb_write_not_started - check if SB_FREEZE_WRITE is not held + * @sb: the super we write to + * + * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN. + */ +static inline bool sb_write_not_started(const struct super_block *sb) +{ + return __sb_write_started(sb, SB_FREEZE_WRITE) <= 0; +} + /** * file_write_started - check if SB_FREEZE_WRITE is held * @file: the file we write to @@ -1729,6 +1740,21 @@ static inline bool file_write_started(const struct file *file) return sb_write_started(file_inode(file)->i_sb); } +/** + * file_write_not_started - check if SB_FREEZE_WRITE is not held + * @file: the file we write to + * + * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN. + * May be false positive with !S_ISREG, because file_start_write() has + * no effect on !S_ISREG. + */ +static inline bool file_write_not_started(const struct file *file) +{ + if (!S_ISREG(file_inode(file)->i_mode)) + return true; + return sb_write_not_started(file_inode(file)->i_sb); +} + /** * sb_end_write - drop write access to a superblock * @sb: the super we wrote to -- 2.39.2