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authorDavid Howells <dhowells@redhat.com>2020-06-12 18:13:52 +0300
committerDavid Howells <dhowells@redhat.com>2020-06-15 17:41:02 +0300
commit793fe82ee33aab1023cf023cd7d744af19a3dff9 (patch)
tree7573b381e7c832b6c589e4057990e6db793567b4 /fs/afs
parentda8d07551275abb3a38fae2d16e02bc9cc7396b2 (diff)
downloadlinux-793fe82ee33aab1023cf023cd7d744af19a3dff9.tar.xz
afs: Fix truncation issues and mmap writeback size
Fix the following issues: (1) Fix writeback to reduce the size of a store operation to i_size, effectively discarding the extra data. The problem comes when afs_page_mkwrite() records that a page is about to be modified by mmap(). It doesn't know what bits of the page are going to be modified, so it records the whole page as being dirty (this is stored in page->private as start and end offsets). Without this, the marshalling for the store to the server extends the size of the file to the end of the page (in afs_fs_store_data() and yfs_fs_store_data()). (2) Fix setattr to actually truncate the pagecache, thereby clearing the discarded part of a file. (3) Fix setattr to check that the new size is okay and to disable ATTR_SIZE if i_size wouldn't change. (4) Force i_size to be updated as the result of a truncate. (5) Don't truncate if ATTR_SIZE is not set. (6) Call pagecache_isize_extended() if the file was enlarged. Note that truncate_set_size() isn't used because the setting of i_size is done inside afs_vnode_commit_status() under the vnode->cb_lock. Found with the generic/029 and generic/393 xfstests. Fixes: 31143d5d515e ("AFS: implement basic file write support") Fixes: 4343d00872e1 ("afs: Get rid of the afs_writeback record") Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/afs')
-rw-r--r--fs/afs/inode.c27
-rw-r--r--fs/afs/internal.h7
-rw-r--r--fs/afs/write.c6
3 files changed, 35 insertions, 5 deletions
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index e99705474dd1..70c925978d10 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -169,7 +169,7 @@ static void afs_apply_status(struct afs_operation *op,
struct timespec64 t;
umode_t mode;
bool data_changed = false;
- bool change_size = false;
+ bool change_size = vp->set_size;
_enter("{%llx:%llu.%u} %s",
vp->fid.vid, vp->fid.vnode, vp->fid.unique,
@@ -799,7 +799,15 @@ void afs_evict_inode(struct inode *inode)
static void afs_setattr_success(struct afs_operation *op)
{
+ struct inode *inode = &op->file[0].vnode->vfs_inode;
+
afs_vnode_commit_status(op, &op->file[0]);
+ if (op->setattr.attr->ia_valid & ATTR_SIZE) {
+ loff_t i_size = inode->i_size, size = op->setattr.attr->ia_size;
+ if (size > i_size)
+ pagecache_isize_extended(inode, i_size, size);
+ truncate_pagecache(inode, size);
+ }
}
static const struct afs_operation_ops afs_setattr_operation = {
@@ -815,6 +823,7 @@ int afs_setattr(struct dentry *dentry, struct iattr *attr)
{
struct afs_operation *op;
struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
+ int ret;
_enter("{%llx:%llu},{n=%pd},%x",
vnode->fid.vid, vnode->fid.vnode, dentry,
@@ -827,6 +836,18 @@ int afs_setattr(struct dentry *dentry, struct iattr *attr)
return 0;
}
+ if (attr->ia_valid & ATTR_SIZE) {
+ if (!S_ISREG(vnode->vfs_inode.i_mode))
+ return -EISDIR;
+
+ ret = inode_newsize_ok(&vnode->vfs_inode, attr->ia_size);
+ if (ret)
+ return ret;
+
+ if (attr->ia_size == i_size_read(&vnode->vfs_inode))
+ attr->ia_valid &= ~ATTR_SIZE;
+ }
+
/* flush any dirty data outstanding on a regular file */
if (S_ISREG(vnode->vfs_inode.i_mode))
filemap_write_and_wait(vnode->vfs_inode.i_mapping);
@@ -840,8 +861,10 @@ int afs_setattr(struct dentry *dentry, struct iattr *attr)
afs_op_set_vnode(op, 0, vnode);
op->setattr.attr = attr;
- if (attr->ia_valid & ATTR_SIZE)
+ if (attr->ia_valid & ATTR_SIZE) {
op->file[0].dv_delta = 1;
+ op->file[0].set_size = true;
+ }
op->ctime = attr->ia_ctime;
op->file[0].update_ctime = 1;
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 92cd6b8cc01f..bdc1e5efebd4 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -744,9 +744,10 @@ struct afs_vnode_param {
afs_dataversion_t dv_before; /* Data version before the call */
unsigned int cb_break_before; /* cb_break + cb_s_break before the call */
u8 dv_delta; /* Expected change in data version */
- bool put_vnode; /* T if we have a ref on the vnode */
- bool need_io_lock; /* T if we need the I/O lock on this */
- bool update_ctime; /* Need to update the ctime */
+ bool put_vnode:1; /* T if we have a ref on the vnode */
+ bool need_io_lock:1; /* T if we need the I/O lock on this */
+ bool update_ctime:1; /* Need to update the ctime */
+ bool set_size:1; /* Must update i_size */
};
/*
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 2003d7ee9e43..7437806332d9 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -492,6 +492,7 @@ static int afs_write_back_from_locked_page(struct address_space *mapping,
unsigned long count, priv;
unsigned n, offset, to, f, t;
pgoff_t start, first, last;
+ loff_t i_size, end;
int loop, ret;
_enter(",%lx", primary_page->index);
@@ -592,7 +593,12 @@ no_more:
first = primary_page->index;
last = first + count - 1;
+ end = (loff_t)last * PAGE_SIZE + to;
+ i_size = i_size_read(&vnode->vfs_inode);
+
_debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to);
+ if (end > i_size)
+ to = i_size & ~PAGE_MASK;
ret = afs_store_data(mapping, first, last, offset, to);
switch (ret) {