While reviewing the patch that would land as 768b611136d0
("MdePkg/UefiLib: introduce EfiOpenFileByDevicePath()", 2018-08-16), Ray
pointed out that distinguishing EFI_FILE_MODE_CREATE was wasteful. Per
spec, if the file to create exists, then EFI_FILE_MODE_CREATE is ignored
by EFI_FILE_PROTOCOL.Open(), and the existent file is opened.
Therefore we don't need an attempt to "open-but-not-create" first, and a
fallback to "open-and-create-too" second -- that behavior is internal to
EFI_FILE_PROTOCOL.Open(). Remove the special-casing of
EFI_FILE_MODE_CREATE.
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Suggested-by: Ruiyu Ni <ruiyu.ni@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1074
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
Notes:
Tested with MdeModulePkg/RamDiskDxe: created a virtual disk from an ISO
file, using the HII form; browsed the disk contents from the UEFI shell.
MdePkg/Include/Library/UefiLib.h | 19 ++--------
MdePkg/Library/UefiLib/UefiLib.c | 40 +++-----------------
2 files changed, 9 insertions(+), 50 deletions(-)
diff --git a/MdePkg/Include/Library/UefiLib.h b/MdePkg/Include/Library/UefiLib.h
index f950f1c9c648..f80067f11103 100644
--- a/MdePkg/Include/Library/UefiLib.h
+++ b/MdePkg/Include/Library/UefiLib.h
@@ -1533,12 +1533,7 @@ EfiLocateProtocolBuffer (
On the remaining device path, the longest initial sequence of
FILEPATH_DEVICE_PATH nodes is node-wise traversed with
- EFI_FILE_PROTOCOL.Open(). For the pathname fragment specified by each
- traversed FILEPATH_DEVICE_PATH node, EfiOpenFileByDevicePath() first masks
- EFI_FILE_MODE_CREATE out of OpenMode, and passes 0 for Attributes. If
- EFI_FILE_PROTOCOL.Open() fails, and OpenMode includes EFI_FILE_MODE_CREATE,
- then the operation is retried with the caller's OpenMode and Attributes
- unmodified.
+ EFI_FILE_PROTOCOL.Open().
(As a consequence, if OpenMode includes EFI_FILE_MODE_CREATE, and Attributes
includes EFI_FILE_DIRECTORY, and each FILEPATH_DEVICE_PATH specifies a single
@@ -1570,18 +1565,10 @@ EfiLocateProtocolBuffer (
the last node in FilePath.
@param[in] OpenMode The OpenMode parameter to pass to
- EFI_FILE_PROTOCOL.Open(). For each
- FILEPATH_DEVICE_PATH node in FilePath,
- EfiOpenFileByDevicePath() first opens the specified
- pathname fragment with EFI_FILE_MODE_CREATE masked
- out of OpenMode and with Attributes set to 0, and
- only retries the operation with EFI_FILE_MODE_CREATE
- unmasked and Attributes propagated if the first open
- attempt fails.
+ EFI_FILE_PROTOCOL.Open().
@param[in] Attributes The Attributes parameter to pass to
- EFI_FILE_PROTOCOL.Open(), when EFI_FILE_MODE_CREATE
- is propagated unmasked in OpenMode.
+ EFI_FILE_PROTOCOL.Open().
@retval EFI_SUCCESS The file or directory has been opened or
created.
diff --git a/MdePkg/Library/UefiLib/UefiLib.c b/MdePkg/Library/UefiLib/UefiLib.c
index 7bcac5613768..39d0ce2b21b3 100644
--- a/MdePkg/Library/UefiLib/UefiLib.c
+++ b/MdePkg/Library/UefiLib/UefiLib.c
@@ -1730,12 +1730,7 @@ EfiLocateProtocolBuffer (
On the remaining device path, the longest initial sequence of
FILEPATH_DEVICE_PATH nodes is node-wise traversed with
- EFI_FILE_PROTOCOL.Open(). For the pathname fragment specified by each
- traversed FILEPATH_DEVICE_PATH node, EfiOpenFileByDevicePath() first masks
- EFI_FILE_MODE_CREATE out of OpenMode, and passes 0 for Attributes. If
- EFI_FILE_PROTOCOL.Open() fails, and OpenMode includes EFI_FILE_MODE_CREATE,
- then the operation is retried with the caller's OpenMode and Attributes
- unmodified.
+ EFI_FILE_PROTOCOL.Open().
(As a consequence, if OpenMode includes EFI_FILE_MODE_CREATE, and Attributes
includes EFI_FILE_DIRECTORY, and each FILEPATH_DEVICE_PATH specifies a single
@@ -1767,18 +1762,10 @@ EfiLocateProtocolBuffer (
the last node in FilePath.
@param[in] OpenMode The OpenMode parameter to pass to
- EFI_FILE_PROTOCOL.Open(). For each
- FILEPATH_DEVICE_PATH node in FilePath,
- EfiOpenFileByDevicePath() first opens the specified
- pathname fragment with EFI_FILE_MODE_CREATE masked
- out of OpenMode and with Attributes set to 0, and
- only retries the operation with EFI_FILE_MODE_CREATE
- unmasked and Attributes propagated if the first open
- attempt fails.
+ EFI_FILE_PROTOCOL.Open().
@param[in] Attributes The Attributes parameter to pass to
- EFI_FILE_PROTOCOL.Open(), when EFI_FILE_MODE_CREATE
- is propagated unmasked in OpenMode.
+ EFI_FILE_PROTOCOL.Open().
@retval EFI_SUCCESS The file or directory has been opened or
created.
@@ -1889,31 +1876,16 @@ EfiOpenFileByDevicePath (
}
//
- // Open the next pathname fragment with EFI_FILE_MODE_CREATE masked out and
- // with Attributes set to 0.
+ // Open or create the file corresponding to the next pathname fragment.
//
Status = LastFile->Open (
LastFile,
&NextFile,
PathName,
- OpenMode & ~(UINT64)EFI_FILE_MODE_CREATE,
- 0
+ OpenMode,
+ Attributes
);
- //
- // Retry with EFI_FILE_MODE_CREATE and the original Attributes if the first
- // attempt failed, and the caller specified EFI_FILE_MODE_CREATE.
- //
- if (EFI_ERROR (Status) && (OpenMode & EFI_FILE_MODE_CREATE) != 0) {
- Status = LastFile->Open (
- LastFile,
- &NextFile,
- PathName,
- OpenMode,
- Attributes
- );
- }
-
//
// Release any AlignedPathName on both error and success paths; PathName is
// no longer needed.
--
2.14.1.3.gb7cf6e02401b
_______________________________________________
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edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel
Reviewed-by: Liming Gao <liming.gao@intel.com>
> -----Original Message-----
> From: Laszlo Ersek [mailto:lersek@redhat.com]
> Sent: Friday, August 17, 2018 7:36 AM
> To: edk2-devel-01 <edk2-devel@lists.01.org>
> Cc: Gao, Liming <liming.gao@intel.com>; Kinney, Michael D <michael.d.kinney@intel.com>; Ni, Ruiyu <ruiyu.ni@intel.com>
> Subject: [PATCH 1/4] MdePkg/UefiLib: don't special-case EFI_FILE_MODE_CREATE in OpenMode
>
> While reviewing the patch that would land as 768b611136d0
> ("MdePkg/UefiLib: introduce EfiOpenFileByDevicePath()", 2018-08-16), Ray
> pointed out that distinguishing EFI_FILE_MODE_CREATE was wasteful. Per
> spec, if the file to create exists, then EFI_FILE_MODE_CREATE is ignored
> by EFI_FILE_PROTOCOL.Open(), and the existent file is opened.
>
> Therefore we don't need an attempt to "open-but-not-create" first, and a
> fallback to "open-and-create-too" second -- that behavior is internal to
> EFI_FILE_PROTOCOL.Open(). Remove the special-casing of
> EFI_FILE_MODE_CREATE.
>
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> Suggested-by: Ruiyu Ni <ruiyu.ni@intel.com>
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1074
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> ---
>
> Notes:
> Tested with MdeModulePkg/RamDiskDxe: created a virtual disk from an ISO
> file, using the HII form; browsed the disk contents from the UEFI shell.
>
> MdePkg/Include/Library/UefiLib.h | 19 ++--------
> MdePkg/Library/UefiLib/UefiLib.c | 40 +++-----------------
> 2 files changed, 9 insertions(+), 50 deletions(-)
>
> diff --git a/MdePkg/Include/Library/UefiLib.h b/MdePkg/Include/Library/UefiLib.h
> index f950f1c9c648..f80067f11103 100644
> --- a/MdePkg/Include/Library/UefiLib.h
> +++ b/MdePkg/Include/Library/UefiLib.h
> @@ -1533,12 +1533,7 @@ EfiLocateProtocolBuffer (
>
> On the remaining device path, the longest initial sequence of
> FILEPATH_DEVICE_PATH nodes is node-wise traversed with
> - EFI_FILE_PROTOCOL.Open(). For the pathname fragment specified by each
> - traversed FILEPATH_DEVICE_PATH node, EfiOpenFileByDevicePath() first masks
> - EFI_FILE_MODE_CREATE out of OpenMode, and passes 0 for Attributes. If
> - EFI_FILE_PROTOCOL.Open() fails, and OpenMode includes EFI_FILE_MODE_CREATE,
> - then the operation is retried with the caller's OpenMode and Attributes
> - unmodified.
> + EFI_FILE_PROTOCOL.Open().
>
> (As a consequence, if OpenMode includes EFI_FILE_MODE_CREATE, and Attributes
> includes EFI_FILE_DIRECTORY, and each FILEPATH_DEVICE_PATH specifies a single
> @@ -1570,18 +1565,10 @@ EfiLocateProtocolBuffer (
> the last node in FilePath.
>
> @param[in] OpenMode The OpenMode parameter to pass to
> - EFI_FILE_PROTOCOL.Open(). For each
> - FILEPATH_DEVICE_PATH node in FilePath,
> - EfiOpenFileByDevicePath() first opens the specified
> - pathname fragment with EFI_FILE_MODE_CREATE masked
> - out of OpenMode and with Attributes set to 0, and
> - only retries the operation with EFI_FILE_MODE_CREATE
> - unmasked and Attributes propagated if the first open
> - attempt fails.
> + EFI_FILE_PROTOCOL.Open().
>
> @param[in] Attributes The Attributes parameter to pass to
> - EFI_FILE_PROTOCOL.Open(), when EFI_FILE_MODE_CREATE
> - is propagated unmasked in OpenMode.
> + EFI_FILE_PROTOCOL.Open().
>
> @retval EFI_SUCCESS The file or directory has been opened or
> created.
> diff --git a/MdePkg/Library/UefiLib/UefiLib.c b/MdePkg/Library/UefiLib/UefiLib.c
> index 7bcac5613768..39d0ce2b21b3 100644
> --- a/MdePkg/Library/UefiLib/UefiLib.c
> +++ b/MdePkg/Library/UefiLib/UefiLib.c
> @@ -1730,12 +1730,7 @@ EfiLocateProtocolBuffer (
>
> On the remaining device path, the longest initial sequence of
> FILEPATH_DEVICE_PATH nodes is node-wise traversed with
> - EFI_FILE_PROTOCOL.Open(). For the pathname fragment specified by each
> - traversed FILEPATH_DEVICE_PATH node, EfiOpenFileByDevicePath() first masks
> - EFI_FILE_MODE_CREATE out of OpenMode, and passes 0 for Attributes. If
> - EFI_FILE_PROTOCOL.Open() fails, and OpenMode includes EFI_FILE_MODE_CREATE,
> - then the operation is retried with the caller's OpenMode and Attributes
> - unmodified.
> + EFI_FILE_PROTOCOL.Open().
>
> (As a consequence, if OpenMode includes EFI_FILE_MODE_CREATE, and Attributes
> includes EFI_FILE_DIRECTORY, and each FILEPATH_DEVICE_PATH specifies a single
> @@ -1767,18 +1762,10 @@ EfiLocateProtocolBuffer (
> the last node in FilePath.
>
> @param[in] OpenMode The OpenMode parameter to pass to
> - EFI_FILE_PROTOCOL.Open(). For each
> - FILEPATH_DEVICE_PATH node in FilePath,
> - EfiOpenFileByDevicePath() first opens the specified
> - pathname fragment with EFI_FILE_MODE_CREATE masked
> - out of OpenMode and with Attributes set to 0, and
> - only retries the operation with EFI_FILE_MODE_CREATE
> - unmasked and Attributes propagated if the first open
> - attempt fails.
> + EFI_FILE_PROTOCOL.Open().
>
> @param[in] Attributes The Attributes parameter to pass to
> - EFI_FILE_PROTOCOL.Open(), when EFI_FILE_MODE_CREATE
> - is propagated unmasked in OpenMode.
> + EFI_FILE_PROTOCOL.Open().
>
> @retval EFI_SUCCESS The file or directory has been opened or
> created.
> @@ -1889,31 +1876,16 @@ EfiOpenFileByDevicePath (
> }
>
> //
> - // Open the next pathname fragment with EFI_FILE_MODE_CREATE masked out and
> - // with Attributes set to 0.
> + // Open or create the file corresponding to the next pathname fragment.
> //
> Status = LastFile->Open (
> LastFile,
> &NextFile,
> PathName,
> - OpenMode & ~(UINT64)EFI_FILE_MODE_CREATE,
> - 0
> + OpenMode,
> + Attributes
> );
>
> - //
> - // Retry with EFI_FILE_MODE_CREATE and the original Attributes if the first
> - // attempt failed, and the caller specified EFI_FILE_MODE_CREATE.
> - //
> - if (EFI_ERROR (Status) && (OpenMode & EFI_FILE_MODE_CREATE) != 0) {
> - Status = LastFile->Open (
> - LastFile,
> - &NextFile,
> - PathName,
> - OpenMode,
> - Attributes
> - );
> - }
> -
> //
> // Release any AlignedPathName on both error and success paths; PathName is
> // no longer needed.
> --
> 2.14.1.3.gb7cf6e02401b
>
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