From 5dbc768f1cd988b87932ba2f176caa006064018d Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Fri, 17 Aug 2018 14:55:23 +0200 Subject: [PATCH] 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 Cc: Michael D Kinney Cc: Ruiyu Ni Suggested-by: Ruiyu Ni Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1074 Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Laszlo Ersek Reviewed-by: Liming Gao --- 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 f950f1c9c6..f80067f111 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 7bcac56137..39d0ce2b21 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.