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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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 > _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
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