From 344713f8b23e9baf104ff599f606b90256835873 Mon Sep 17 00:00:00 2001 From: Felix Frank Date: Tue, 12 May 2009 18:56:50 +0000 Subject: [PATCH] STABLE14-linux-mmap-antirecursion-fix-20090512 LICENSE IPL10 FIXES 124627 fix the mmap anti-recursion protection to set and mask CPageWrite appropriately and with the correct lock protection. this leaves us with an issue to handle when the mmap'd file is larger (possibly considerably larger) than the cache (cherry picked from commit 5e0e1ea2540d0cb7d7274350eb1fadfd41733ea4) --- src/afs/LINUX/osi_vm.c | 5 +---- src/afs/LINUX/osi_vnodeops.c | 22 +++++++++++++++------- 2 files changed, 16 insertions(+), 11 deletions(-) diff --git a/src/afs/LINUX/osi_vm.c b/src/afs/LINUX/osi_vm.c index a08da8faf..4745b3819 100644 --- a/src/afs/LINUX/osi_vm.c +++ b/src/afs/LINUX/osi_vm.c @@ -102,9 +102,7 @@ osi_VM_StoreAllSegments(struct vcache *avc) { struct inode *ip = AFSTOV(avc); - if (!avc->states & CPageWrite) - avc->states |= CPageWrite; - else + if (avc->states & CPageWrite) return; /* someone already writing */ #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,5) @@ -120,7 +118,6 @@ osi_VM_StoreAllSegments(struct vcache *avc) AFS_GLOCK(); ObtainWriteLock(&avc->lock, 121); #endif - avc->states &= ~CPageWrite; } /* Purge VM for a file when its callback is revoked. diff --git a/src/afs/LINUX/osi_vnodeops.c b/src/afs/LINUX/osi_vnodeops.c index 9d2a6052a..76bebd77e 100644 --- a/src/afs/LINUX/osi_vnodeops.c +++ b/src/afs/LINUX/osi_vnodeops.c @@ -1091,7 +1091,7 @@ afs_linux_lookup(struct inode *dip, struct dentry *dp) #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,10) if (code == ENOENT) return ERR_PTR(0); - else if ((code >= 0) && (code <= MAX_ERRNO)) + else if ((code > 0) && (code <= MAX_ERRNO)) return ERR_PTR(-code); else return ERR_PTR(-EIO); @@ -1567,9 +1567,9 @@ afs_linux_writepage_sync(struct inode *ip, struct page *pp, ICL_TYPE_POINTER, pp, ICL_TYPE_INT32, page_count(pp), ICL_TYPE_INT32, 99999); - ObtainReadLock(&vcp->lock); + ObtainWriteLock(&vcp->lock, 532); if (vcp->states & CPageWrite) { - ReleaseReadLock(&vcp->lock); + ReleaseWriteLock(&vcp->lock); AFS_GUNLOCK(); unlock_kernel(); crfree(credp); @@ -1585,7 +1585,8 @@ afs_linux_writepage_sync(struct inode *ip, struct page *pp, return(0); #endif } - ReleaseReadLock(&vcp->lock); + vcp->states |= CPageWrite; + ReleaseWriteLock(&vcp->lock); setup_uio(&tuio, &iovec, buffer, base, count, UIO_WRITE, AFS_UIOSYS); @@ -1594,16 +1595,18 @@ afs_linux_writepage_sync(struct inode *ip, struct page *pp, i_size_write(ip, vcp->m.Length); ip->i_blocks = ((vcp->m.Length + 1023) >> 10) << 1; + ObtainWriteLock(&vcp->lock, 533); if (!code) { struct vrequest treq; - ObtainWriteLock(&vcp->lock, 533); if (!afs_InitReq(&treq, credp)) code = afs_DoPartialWrite(vcp, &treq); - ReleaseWriteLock(&vcp->lock); } code = code ? -code : count - tuio.uio_resid; + vcp->states &= ~CPageWrite; + ReleaseWriteLock(&vcp->lock); + afs_Trace4(afs_iclSetp, CM_TRACE_UPDATEPAGE, ICL_TYPE_POINTER, vcp, ICL_TYPE_POINTER, pp, ICL_TYPE_INT32, page_count(pp), ICL_TYPE_INT32, code); @@ -1658,7 +1661,12 @@ afs_linux_writepage(struct page *pp) do_it: status = afs_linux_writepage_sync(inode, pp, 0, offset); SetPageUptodate(pp); - UnlockPage(pp); +#if defined(WRITEPAGE_ACTIVATE) + if ( status != WRITEPAGE_ACTIVATE ) +#else + if ( status != AOP_WRITEPAGE_ACTIVATE ) +#endif + UnlockPage(pp); if (status == offset) return 0; else -- 2.39.5