Kirk McKusick 513274c79c Clear the IN_SIZEMOD and IN_IBLKDATA flags only when doing a ... synchronous inode update. The IN_SIZEMOD and IN_IBLKDATA flags indicate changes to the file size and block pointer fields in the inode. When these fields have been changed, the fsync() and fsyncdata() system calls must write the inode to ensure their semantics that the file is on stable store. The IN_SIZEMOD and IN_IBLKDATA flags cannot be cleared until a synchronous write of the inode is done. If they are cleared on an asynchronous write, then the inode may not yet have been written to the disk when an fsync() or fsyncdata() call is done. Absent these flags, these calls would not know that they needed to write the inode. Thus, these flags only can be cleared on synchronous writes of the inode. Since the inode will be locked for the duration of the I/O that writes it to disk, no fsync() or fsyncdata() will be able to run before the on-disk inode is complete. Reviewed by: kib MFC with: -r361785 Differential revision: https://reviews.freebsd.org/D25072		2020-06-06 20:17:56 +00:00
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ffs	Clear the IN_SIZEMOD and IN_IBLKDATA flags only when doing a	2020-06-06 20:17:56 +00:00
ufs	Further evaluation of the POSIX spec for fdatasync() shows that it	2020-06-05 01:00:55 +00:00