76398425bb
Removing the BKL from FASYNC handling ran into the challenge of keeping the setting of the FASYNC bit in filp->f_flags atomic with regard to calls to the underlying fasync() function. Andi Kleen suggested moving the handling of that bit into fasync(); this patch does exactly that. As a result, we have a couple of internal API changes: fasync() must now manage the FASYNC bit, and it will be called without the BKL held. As it happens, every fasync() implementation in the kernel with one exception calls fasync_helper(). So, if we make fasync_helper() set the FASYNC bit, we can avoid making any changes to the other fasync() functions - as long as those functions, themselves, have proper locking. Most fasync() implementations do nothing but call fasync_helper() - which has its own lock - so they are easily verified as correct. The BKL had already been pushed down into the rest. The networking code has its own version of fasync_helper(), so that code has been augmented with explicit FASYNC bit handling. Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: David Miller <davem@davemloft.net> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net> |
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| .. | ||
| configfs | ||
| 00-INDEX | ||
| 9p.txt | ||
| adfs.txt | ||
| affs.txt | ||
| afs.txt | ||
| autofs4-mount-control.txt | ||
| automount-support.txt | ||
| befs.txt | ||
| bfs.txt | ||
| btrfs.txt | ||
| cifs.txt | ||
| coda.txt | ||
| cramfs.txt | ||
| dentry-locking.txt | ||
| devpts.txt | ||
| directory-locking | ||
| dlmfs.txt | ||
| dnotify.txt | ||
| ecryptfs.txt | ||
| Exporting | ||
| ext2.txt | ||
| ext3.txt | ||
| ext4.txt | ||
| fiemap.txt | ||
| files.txt | ||
| fuse.txt | ||
| gfs2-glocks.txt | ||
| gfs2.txt | ||
| hfs.txt | ||
| hfsplus.txt | ||
| hpfs.txt | ||
| inotify.txt | ||
| isofs.txt | ||
| jfs.txt | ||
| Locking | ||
| locks.txt | ||
| mandatory-locking.txt | ||
| ncpfs.txt | ||
| nfs-rdma.txt | ||
| nfsroot.txt | ||
| ntfs.txt | ||
| ocfs2.txt | ||
| omfs.txt | ||
| porting | ||
| proc.txt | ||
| quota.txt | ||
| ramfs-rootfs-initramfs.txt | ||
| relay.txt | ||
| romfs.txt | ||
| rpc-cache.txt | ||
| seq_file.txt | ||
| sharedsubtree.txt | ||
| smbfs.txt | ||
| spufs.txt | ||
| squashfs.txt | ||
| sysfs-pci.txt | ||
| sysfs.txt | ||
| sysv-fs.txt | ||
| tmpfs.txt | ||
| ubifs.txt | ||
| udf.txt | ||
| ufs.txt | ||
| vfat.txt | ||
| vfs.txt | ||
| xfs.txt | ||
| xip.txt | ||