xfs: recall pNFS layouts on conflicting access

Recall all outstanding pNFS layouts and truncates, writes and similar extent
list modifying operations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 712d312d8e3ec4fd980c2aaa0fb131fa6b14bf4f..56dcfce8d7d67a291457daaf0f150e1e48e9c8fe 100644 (file)
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -36,6 +36,7 @@
 #include "xfs_trace.h"
 #include "xfs_log.h"
 #include "xfs_icache.h"
+#include "xfs_pnfs.h"
 
 #include <linux/aio.h>
 #include <linux/dcache.h>
@@ -554,6 +555,10 @@ restart:
        if (error)
                return error;
 
+       error = xfs_break_layouts(inode, iolock);
+       if (error)
+               return error;
+
        /*
         * If the offset is beyond the size of the file, we need to zero any
         * blocks that fall between the existing EOF and the start of this
@@ -822,6 +827,7 @@ xfs_file_fallocate(
        struct xfs_inode        *ip = XFS_I(inode);
        long                    error;
        enum xfs_prealloc_flags flags = 0;
+       uint                    iolock = XFS_IOLOCK_EXCL;
        loff_t                  new_size = 0;
 
        if (!S_ISREG(inode->i_mode))
@@ -830,7 +836,11 @@ xfs_file_fallocate(
                     FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE))
                return -EOPNOTSUPP;
 
-       xfs_ilock(ip, XFS_IOLOCK_EXCL);
+       xfs_ilock(ip, iolock);
+       error = xfs_break_layouts(inode, &iolock);
+       if (error)
+               goto out_unlock;
+
        if (mode & FALLOC_FL_PUNCH_HOLE) {
                error = xfs_free_file_space(ip, offset, len);
                if (error)
@@ -894,7 +904,7 @@ xfs_file_fallocate(
        }
 
 out_unlock:
-       xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+       xfs_iunlock(ip, iolock);
        return error;
 }
 

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index f7afb86c91487fc0a89c98578a28b3a1dfda83e0..bf70a2affb05b0b736d27ca1ceebac68015e5f7c 100644 (file)
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -39,6 +39,7 @@
 #include "xfs_icache.h"
 #include "xfs_symlink.h"
 #include "xfs_trans.h"
+#include "xfs_pnfs.h"
 
 #include <linux/capability.h>
 #include <linux/dcache.h>
@@ -608,6 +609,7 @@ xfs_ioc_space(
 {
        struct iattr            iattr;
        enum xfs_prealloc_flags flags = 0;
+       uint                    iolock = XFS_IOLOCK_EXCL;
        int                     error;
 
        /*
@@ -636,7 +638,10 @@ xfs_ioc_space(
        if (error)
                return error;
 
-       xfs_ilock(ip, XFS_IOLOCK_EXCL);
+       xfs_ilock(ip, iolock);
+       error = xfs_break_layouts(inode, &iolock);
+       if (error)
+               goto out_unlock;
 
        switch (bf->l_whence) {
        case 0: /*SEEK_SET*/
@@ -725,7 +730,7 @@ xfs_ioc_space(
        error = xfs_update_prealloc_flags(ip, flags);
 
 out_unlock:
-       xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+       xfs_iunlock(ip, iolock);
        mnt_drop_write_file(filp);
        return error;
 }

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index e5e2ea0d0b2501a24b4c164b53fc0ee6f235897a..d919ad7b16bf9acbe01c6531a9254b372426911a 100644 (file)
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -37,6 +37,7 @@
 #include "xfs_da_btree.h"
 #include "xfs_dir2.h"
 #include "xfs_trans_space.h"
+#include "xfs_pnfs.h"
 
 #include <linux/capability.h>
 #include <linux/xattr.h>
@@ -979,9 +980,13 @@ xfs_vn_setattr(
        int                     error;
 
        if (iattr->ia_valid & ATTR_SIZE) {
-               xfs_ilock(ip, XFS_IOLOCK_EXCL);
-               error = xfs_setattr_size(ip, iattr);
-               xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+               uint            iolock = XFS_IOLOCK_EXCL;
+
+               xfs_ilock(ip, iolock);
+               error = xfs_break_layouts(dentry->d_inode, &iolock);
+               if (!error)
+                       error = xfs_setattr_size(ip, iattr);
+               xfs_iunlock(ip, iolock);
        } else {
                error = xfs_setattr_nonsize(ip, iattr, 0);
        }

diff --git a/fs/xfs/xfs_pnfs.c b/fs/xfs/xfs_pnfs.c
index 89912b34f18461e29c9cc9d0e471ebafff8bedc0..4b33ef112400cc01507b96632d93775839573d99 100644 (file)
--- a/fs/xfs/xfs_pnfs.c
+++ b/fs/xfs/xfs_pnfs.c
@@ -18,6 +18,36 @@
 #include "xfs_bit.h"
 #include "xfs_pnfs.h"
 
+/*
+ * Ensure that we do not have any outstanding pNFS layouts that can be used by
+ * clients to directly read from or write to this inode.  This must be called
+ * before every operation that can remove blocks from the extent map.
+ * Additionally we call it during the write operation, where aren't concerned
+ * about exposing unallocated blocks but just want to provide basic
+ * synchronization between a local writer and pNFS clients.  mmap writes would
+ * also benefit from this sort of synchronization, but due to the tricky locking
+ * rules in the page fault path we don't bother.
+ */
+int
+xfs_break_layouts(
+       struct inode            *inode,
+       uint                    *iolock)
+{
+       struct xfs_inode        *ip = XFS_I(inode);
+       int                     error;
+
+       ASSERT(xfs_isilocked(ip, XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL));
+
+       while ((error = break_layout(inode, false) == -EWOULDBLOCK)) {
+               xfs_iunlock(ip, *iolock);
+               error = break_layout(inode, true);
+               *iolock = XFS_IOLOCK_EXCL;
+               xfs_ilock(ip, *iolock);
+       }
+
+       return error;
+}
+
 /*
  * Get a unique ID including its location so that the client can identify
  * the exported device.

diff --git a/fs/xfs/xfs_pnfs.h b/fs/xfs/xfs_pnfs.h
index 0d91255a89aeb7281dde49dc6e577949f919be68..b7fbfce660f68516d261e56f2c0ea2c78291832c 100644 (file)
--- a/fs/xfs/xfs_pnfs.h
+++ b/fs/xfs/xfs_pnfs.h
@@ -7,5 +7,12 @@ int xfs_fs_map_blocks(struct inode *inode, loff_t offset, u64 length,
                struct iomap *iomap, bool write, u32 *device_generation);
 int xfs_fs_commit_blocks(struct inode *inode, struct iomap *maps, int nr_maps,
                struct iattr *iattr);
+
+int xfs_break_layouts(struct inode *inode, uint *iolock);
+#else
+static inline int xfs_break_layouts(struct inode *inode, uint *iolock)
+{
+       return 0;
+}
 #endif /* CONFIG_NFSD_PNFS */
 #endif /* _XFS_PNFS_H */