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i_alloc_sem is a rather special rw_semaphore. It's the last one that may be released by a non-owner, and it's write side is always mirrored by real exclusion. It's intended use it to wait for all pending direct I/O requests to finish before starting a truncate. Replace it with a hand-grown construct: - exclusion for truncates is already guaranteed by i_mutex, so it can simply fall way - the reader side is replaced by an i_dio_count member in struct inode that counts the number of pending direct I/O requests. Truncate can't proceed as long as it's non-zero - when i_dio_count reaches non-zero we wake up a pending truncate using wake_up_bit on a new bit in i_flags - new references to i_dio_count can't appear while we are waiting for it to read zero because the direct I/O count always needs i_mutex (or an equivalent like XFS's i_iolock) for starting a new operation. This scheme is much simpler, and saves the space of a spinlock_t and a struct list_head in struct inode (typically 160 bits on a non-debug 64-bit system). Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
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| .. | ||
| aops.c | ||
| aops.h | ||
| attrib.c | ||
| attrib.h | ||
| bitmap.c | ||
| bitmap.h | ||
| collate.c | ||
| collate.h | ||
| compress.c | ||
| debug.c | ||
| debug.h | ||
| dir.c | ||
| dir.h | ||
| endian.h | ||
| file.c | ||
| index.c | ||
| index.h | ||
| inode.c | ||
| inode.h | ||
| Kconfig | ||
| layout.h | ||
| lcnalloc.c | ||
| lcnalloc.h | ||
| logfile.c | ||
| logfile.h | ||
| Makefile | ||
| malloc.h | ||
| mft.c | ||
| mft.h | ||
| mst.c | ||
| namei.c | ||
| ntfs.h | ||
| quota.c | ||
| quota.h | ||
| runlist.c | ||
| runlist.h | ||
| super.c | ||
| sysctl.c | ||
| sysctl.h | ||
| time.h | ||
| types.h | ||
| unistr.c | ||
| upcase.c | ||
| usnjrnl.c | ||
| usnjrnl.h | ||
| volume.h | ||