[edk2-devel] [edk2 PATCH 46/48] OvmfPkg/VirtioFsDxe: add helper for determining access time updates
Laszlo Ersek
lersek at redhat.com
Wed Dec 16 21:11:23 UTC 2020
Add the VirtioFsGetFuseTimeUpdates() function, for determining whether an
EFI_FILE_PROTOCOL.SetInfo() invocation requests access time updates.
Cc: Ard Biesheuvel <ard.biesheuvel at arm.com>
Cc: Jordan Justen <jordan.l.justen at intel.com>
Cc: Philippe Mathieu-Daudé <philmd at redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek at redhat.com>
---
OvmfPkg/VirtioFsDxe/VirtioFsDxe.h | 10 ++
OvmfPkg/VirtioFsDxe/Helpers.c | 106 ++++++++++++++++++++
2 files changed, 116 insertions(+)
diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
index 096756302942..4331cabbd40e 100644
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
@@ -285,16 +285,26 @@ VirtioFsFuseDirentPlusToEfiFileInfo (
VOID
VirtioFsGetFuseSizeUpdate (
IN EFI_FILE_INFO *Info,
IN EFI_FILE_INFO *NewInfo,
OUT BOOLEAN *Update,
OUT UINT64 *Size
);
+EFI_STATUS
+VirtioFsGetFuseTimeUpdates (
+ IN EFI_FILE_INFO *Info,
+ IN EFI_FILE_INFO *NewInfo,
+ OUT BOOLEAN *UpdateAtime,
+ OUT BOOLEAN *UpdateMtime,
+ OUT UINT64 *Atime,
+ OUT UINT64 *Mtime
+ );
+
//
// Wrapper functions for FUSE commands (primitives).
//
EFI_STATUS
VirtioFsFuseLookup (
IN OUT VIRTIO_FS *VirtioFs,
IN UINT64 DirNodeId,
diff --git a/OvmfPkg/VirtioFsDxe/Helpers.c b/OvmfPkg/VirtioFsDxe/Helpers.c
index 838971bd2c85..c85c7400f2be 100644
--- a/OvmfPkg/VirtioFsDxe/Helpers.c
+++ b/OvmfPkg/VirtioFsDxe/Helpers.c
@@ -2208,8 +2208,114 @@ VirtioFsGetFuseSizeUpdate (
if (IsDirectory || Info->FileSize == NewInfo->FileSize) {
*Update = FALSE;
return;
}
*Update = TRUE;
*Size = NewInfo->FileSize;
}
+
+/**
+ Given an EFI_FILE_INFO object received in an EFI_FILE_PROTOCOL.SetInfo()
+ call, determine whether updating the last access time and/or the last
+ modification time of the file is necessary, relative to an EFI_FILE_INFO
+ object describing the current state of the file.
+
+ @param[in] Info The EFI_FILE_INFO describing the current state of
+ the file. The caller is responsible for populating
+ Info on input with VirtioFsFuseAttrToEfiFileInfo(),
+ from the current FUSE attributes of the file. The
+ Info->Size and Info->FileName members are ignored.
+
+ @param[in] NewInfo The EFI_FILE_INFO object received in the
+ EFI_FILE_PROTOCOL.SetInfo() call.
+
+ @param[out] UpdateAtime Set to TRUE on output if the last access time needs
+ to be updated. Set to FALSE otherwise.
+
+ @param[out] UpdateMtime Set to TRUE on output if the last modification time
+ needs to be updated. Set to FALSE otherwise.
+
+ @param[out] Atime If UpdateAtime is set to TRUE, then Atime provides
+ the last access timestamp to set (as seconds since
+ the Epoch). Otherwise, Atime is not written to.
+
+ @param[out] Mtime If UpdateMtime is set to TRUE, then Mtime provides
+ the last modification timestamp to set (as seconds
+ since the Epoch). Otherwise, Mtime is not written
+ to.
+
+ @retval EFI_SUCCESS Output parameters have been set successfully.
+
+ @retval EFI_ACCESS_DENIED NewInfo requests changing both CreateTime and
+ ModificationTime, but to values that differ from
+ each other. The Virtio Filesystem device does not
+ support this.
+**/
+EFI_STATUS
+VirtioFsGetFuseTimeUpdates (
+ IN EFI_FILE_INFO *Info,
+ IN EFI_FILE_INFO *NewInfo,
+ OUT BOOLEAN *UpdateAtime,
+ OUT BOOLEAN *UpdateMtime,
+ OUT UINT64 *Atime,
+ OUT UINT64 *Mtime
+ )
+{
+ EFI_TIME *Time[3];
+ EFI_TIME *NewTime[ARRAY_SIZE (Time)];
+ UINTN Idx;
+ STATIC CONST EFI_TIME ZeroTime;
+ BOOLEAN Change[ARRAY_SIZE (Time)];
+ UINT64 Seconds[ARRAY_SIZE (Time)];
+
+ Time[0] = &Info->CreateTime;
+ Time[1] = &Info->LastAccessTime;
+ Time[2] = &Info->ModificationTime;
+ NewTime[0] = &NewInfo->CreateTime;
+ NewTime[1] = &NewInfo->LastAccessTime;
+ NewTime[2] = &NewInfo->ModificationTime;
+
+ //
+ // Determine which timestamps differ from the current state. (A zero time
+ // means "don't update", per UEFI spec.) For each timestamp that's being
+ // changed, calculate the seconds since the Epoch.
+ //
+ for (Idx = 0; Idx < ARRAY_SIZE (Time); Idx++) {
+ if (CompareMem (NewTime[Idx], &ZeroTime, sizeof (EFI_TIME)) == 0 ||
+ CompareMem (NewTime[Idx], Time[Idx], sizeof (EFI_TIME)) == 0) {
+ Change[Idx] = FALSE;
+ } else {
+ Change[Idx] = TRUE;
+ Seconds[Idx] = EfiTimeToEpoch (NewTime[Idx]);
+ }
+ }
+
+ //
+ // If a change is requested for exactly one of CreateTime and
+ // ModificationTime, we'll change the last modification time. If changes are
+ // requested for both, and to the same timestamp, we'll similarly update the
+ // last modification time. If changes are requested for both, but to
+ // different timestamps, we reject the request.
+ //
+ if (Change[0] && Change[2] && Seconds[0] != Seconds[2]) {
+ return EFI_ACCESS_DENIED;
+ }
+
+ *UpdateAtime = FALSE;
+ *UpdateMtime = FALSE;
+
+ if (Change[0]) {
+ *UpdateMtime = TRUE;
+ *Mtime = Seconds[0];
+ }
+ if (Change[1]) {
+ *UpdateAtime = TRUE;
+ *Atime = Seconds[1];
+ }
+ if (Change[2]) {
+ *UpdateMtime = TRUE;
+ *Mtime = Seconds[2];
+ }
+
+ return EFI_SUCCESS;
+}
--
2.19.1.3.g30247aa5d201
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