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6b2f3d1f76
While Linux provided an O_SYNC flag basically since day 1, it took until Linux 2.4.0-test12pre2 to actually get it implemented for filesystems, since that day we had generic_osync_around with only minor changes and the great "For now, when the user asks for O_SYNC, we'll actually give O_DSYNC" comment. This patch intends to actually give us real O_SYNC semantics in addition to the O_DSYNC semantics. After Jan's O_SYNC patches which are required before this patch it's actually surprisingly simple, we just need to figure out when to set the datasync flag to vfs_fsync_range and when not. This patch renames the existing O_SYNC flag to O_DSYNC while keeping it's numerical value to keep binary compatibility, and adds a new real O_SYNC flag. To guarantee backwards compatiblity it is defined as expanding to both the O_DSYNC and the new additional binary flag (__O_SYNC) to make sure we are backwards-compatible when compiled against the new headers. This also means that all places that don't care about the differences can just check O_DSYNC and get the right behaviour for O_SYNC, too - only places that actuall care need to check __O_SYNC in addition. Drivers and network filesystems have been updated in a fail safe way to always do the full sync magic if O_DSYNC is set. The few places setting O_SYNC for lower layers are kept that way for now to stay failsafe. We enforce that O_DSYNC is set when __O_SYNC is set early in the open path to make sure we always get these sane options. Note that parisc really screwed up their headers as they already define a O_DSYNC that has always been a no-op. We try to repair it by using it for the new O_DSYNC and redefinining O_SYNC to send both the traditional O_SYNC numerical value _and_ the O_DSYNC one. Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Grant Grundler <grundler@parisc-linux.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Dilger <adilger@sun.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Acked-by: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jan Kara <jack@suse.cz> |
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| .. | ||
| linux-2.6 | ||
| quota | ||
| support | ||
| Kconfig | ||
| Makefile | ||
| xfs.h | ||
| xfs_acl.h | ||
| xfs_ag.h | ||
| xfs_alloc.c | ||
| xfs_alloc.h | ||
| xfs_alloc_btree.c | ||
| xfs_alloc_btree.h | ||
| xfs_arch.h | ||
| xfs_attr.c | ||
| xfs_attr.h | ||
| xfs_attr_leaf.c | ||
| xfs_attr_leaf.h | ||
| xfs_attr_sf.h | ||
| xfs_bit.c | ||
| xfs_bit.h | ||
| xfs_bmap.c | ||
| xfs_bmap.h | ||
| xfs_bmap_btree.c | ||
| xfs_bmap_btree.h | ||
| xfs_btree.c | ||
| xfs_btree.h | ||
| xfs_btree_trace.c | ||
| xfs_btree_trace.h | ||
| xfs_buf_item.c | ||
| xfs_buf_item.h | ||
| xfs_da_btree.c | ||
| xfs_da_btree.h | ||
| xfs_dfrag.c | ||
| xfs_dfrag.h | ||
| xfs_dinode.h | ||
| xfs_dir2.c | ||
| xfs_dir2.h | ||
| xfs_dir2_block.c | ||
| xfs_dir2_block.h | ||
| xfs_dir2_data.c | ||
| xfs_dir2_data.h | ||
| xfs_dir2_leaf.c | ||
| xfs_dir2_leaf.h | ||
| xfs_dir2_node.c | ||
| xfs_dir2_node.h | ||
| xfs_dir2_sf.c | ||
| xfs_dir2_sf.h | ||
| xfs_dir2_trace.c | ||
| xfs_dir2_trace.h | ||
| xfs_dmapi.h | ||
| xfs_dmops.c | ||
| xfs_error.c | ||
| xfs_error.h | ||
| xfs_extfree_item.c | ||
| xfs_extfree_item.h | ||
| xfs_filestream.c | ||
| xfs_filestream.h | ||
| xfs_fs.h | ||
| xfs_fsops.c | ||
| xfs_fsops.h | ||
| xfs_ialloc.c | ||
| xfs_ialloc.h | ||
| xfs_ialloc_btree.c | ||
| xfs_ialloc_btree.h | ||
| xfs_iget.c | ||
| xfs_inode.c | ||
| xfs_inode.h | ||
| xfs_inode_item.c | ||
| xfs_inode_item.h | ||
| xfs_inum.h | ||
| xfs_iomap.c | ||
| xfs_iomap.h | ||
| xfs_itable.c | ||
| xfs_itable.h | ||
| xfs_log.c | ||
| xfs_log.h | ||
| xfs_log_priv.h | ||
| xfs_log_recover.c | ||
| xfs_log_recover.h | ||
| xfs_mount.c | ||
| xfs_mount.h | ||
| xfs_mru_cache.c | ||
| xfs_mru_cache.h | ||
| xfs_quota.h | ||
| xfs_refcache.h | ||
| xfs_rename.c | ||
| xfs_rtalloc.c | ||
| xfs_rtalloc.h | ||
| xfs_rw.c | ||
| xfs_rw.h | ||
| xfs_sb.h | ||
| xfs_trans.c | ||
| xfs_trans.h | ||
| xfs_trans_ail.c | ||
| xfs_trans_buf.c | ||
| xfs_trans_extfree.c | ||
| xfs_trans_inode.c | ||
| xfs_trans_item.c | ||
| xfs_trans_priv.h | ||
| xfs_trans_space.h | ||
| xfs_types.h | ||
| xfs_utils.c | ||
| xfs_utils.h | ||
| xfs_vnodeops.c | ||
| xfs_vnodeops.h | ||