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2017-04-23Merge branch 'dt/xgethostname-nul-termination'Libravatar Junio C Hamano1-0/+13
gethostname(2) may not NUL terminate the buffer if hostname does not fit; unfortunately there is no easy way to see if our buffer was too small, but at least this will make sure we will not end up using garbage past the end of the buffer. * dt/xgethostname-nul-termination: xgethostname: handle long hostnames use HOST_NAME_MAX to size buffers for gethostname(2)
2017-04-18xgethostname: handle long hostnamesLibravatar David Turner1-0/+13
If the full hostname doesn't fit in the buffer supplied to gethostname, POSIX does not specify whether the buffer will be null-terminated, so to be safe, we should do it ourselves. Introduce new function, xgethostname, which ensures that there is always a \0 at the end of the buffer. Signed-off-by: David Turner <dturner@twosigma.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-28wrapper.c: remove unused gitmkstemps() functionLibravatar Ramsay Jones1-7/+0
The last call to the mkstemps() function was removed in commit 659488326 ("wrapper.c: delete dead function git_mkstemps()", 22-04-2016). In order to support platforms without mkstemps(), this functionality was provided, along with a Makefile build variable (NO_MKSTEMPS), by the gitmkstemps() function. Remove the dead code, along with the defunct build machinery. Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-28wrapper.c: remove unused git_mkstemp() functionLibravatar Ramsay Jones1-17/+0
The last caller of git_mkstemp() was removed in commit 6fec0a89 ("verify_signed_buffer: use tempfile object", 16-06-2016). Since the introduction of the 'tempfile' APIs, along with git_mkstemp_mode, it is unlikely that new callers will materialize. Remove the dead code. Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-19Merge branch 'jk/write-file'Libravatar Junio C Hamano1-40/+12
General code clean-up around a helper function to write a single-liner to a file. * jk/write-file: branch: use write_file_buf instead of write_file use write_file_buf where applicable write_file: add format attribute write_file: add pointer+len variant write_file: use xopen write_file: drop "gently" form branch: use non-gentle write_file for branch description am: ignore return value of write_file() config: fix bogus fd check when setting up default config
2016-07-19Merge branch 'sb/submodule-parallel-fetch'Libravatar Junio C Hamano1-16/+27
Fix recently introduced codepaths that are involved in parallel submodule operations, which gave up on reading too early, and could have wasted CPU while attempting to write under a corner case condition. * sb/submodule-parallel-fetch: hoist out handle_nonblock function for xread and xwrite xwrite: poll on non-blocking FDs xread: retry after poll on EAGAIN/EWOULDBLOCK
2016-07-11hoist out handle_nonblock function for xread and xwriteLibravatar Eric Wong1-28/+20
At least for me, this improves the readability of xread and xwrite; hopefully allowing missing "continue" statements to be spotted more easily. Signed-off-by: Eric Wong <e@80x24.org> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-08write_file: add pointer+len variantLibravatar Jeff King1-5/+11
There are many callsites which could use write_file, but for which it is a little awkward because they have a strbuf or other pointer/len combo. Specifically: 1. write_file() takes a format string, so we have to use "%s" or "%.*s", which are ugly. 2. Using any form of "%s" does not handle embedded NULs in the output. That probably doesn't matter for our call-sites, but it's nicer not to have to worry. 3. It's less efficient; we format into another strbuf just to do the write. That's probably not measurably slow for our uses, but it's simply inelegant. We can fix this by providing a helper to write out the formatted buffer, and just calling it from write_file(). Note that we don't do the usual "complete with a newline" that write_file does. If the caller has their own buffer, there's a reasonable chance they're doing something more complicated than a single line, and they can call strbuf_complete_line() themselves. We could go even further and add strbuf_write_file(), but it doesn't save much: - write_file_buf(path, sb.buf, sb.len); + strbuf_write_file(&sb, path); It would also be somewhat asymmetric with strbuf_read_file, which actually returns errors rather than dying (and the error handling is most of the benefit of write_file() in the first place). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-08write_file: use xopenLibravatar Jeff King1-3/+1
This simplifies the code a tiny bit, and provides consistent error messages with other users of xopen(). While we're here, let's also switch to using O_WRONLY. We know we're only going to open/write/close the file, so there's no point in asking for O_RDWR. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-08write_file: drop "gently" formLibravatar Jeff King1-43/+11
There are no callers left of write_file_gently(). Let's drop it, as it doesn't seem likely for new callers to be added (since its inception, the only callers who wanted the gentle form generally just died immediately themselves, and have since been converted). While we're there, let's also drop the "int" return from write_file, as it is never meaningful (in the non-gentle form, we always either die or return 0). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-06-27xwrite: poll on non-blocking FDsLibravatar Eric Wong1-2/+20
write(2) can hit the same EAGAIN/EWOULDBLOCK errors as read(2), so busy-looping on a non-blocking FD is a waste of resources. Currently, I do not know of a way for this happen: * the NonBlocking directive in systemd does not apply to stdin, stdout, or stderr. * xinetd provides no way to set the non-blocking flag at all But theoretically, it's possible a careless C10K HTTP server could use pipe2(..., O_NONBLOCK) to setup a pipe for git-http-backend with only the intent to use non-blocking reads; but accidentally leave non-blocking set on the write end passed as stdout to git-upload-pack. Followup-to: 1079c4be0b720 ("xread: poll on non blocking fds") Signed-off-by: Eric Wong <e@80x24.org> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-06-27xread: retry after poll on EAGAIN/EWOULDBLOCKLibravatar Eric Wong1-0/+1
We should continue to loop after EAGAIN/EWOULDBLOCK as the intent of xread is to try until there is available data, EOF, or an unrecoverable error. Fixes: 1079c4be0b720 ("xread: poll on non blocking fds") Signed-off-by: Eric Wong <e@80x24.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-05-17Merge branch 'nd/error-errno'Libravatar Junio C Hamano1-2/+2
The code for warning_errno/die_errno has been refactored and a new error_errno() reporting helper is introduced. * nd/error-errno: (41 commits) wrapper.c: use warning_errno() vcs-svn: use error_errno() upload-pack.c: use error_errno() unpack-trees.c: use error_errno() transport-helper.c: use error_errno() sha1_file.c: use {error,die,warning}_errno() server-info.c: use error_errno() sequencer.c: use error_errno() run-command.c: use error_errno() rerere.c: use error_errno() and warning_errno() reachable.c: use error_errno() mailmap.c: use error_errno() ident.c: use warning_errno() http.c: use error_errno() and warning_errno() grep.c: use error_errno() gpg-interface.c: use error_errno() fast-import.c: use error_errno() entry.c: use error_errno() editor.c: use error_errno() diff-no-index.c: use error_errno() ...
2016-05-09wrapper.c: use warning_errno()Libravatar Nguyễn Thái Ngọc Duy1-2/+2
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-04-22wrapper.c: delete dead function git_mkstemps()Libravatar Nguyễn Thái Ngọc Duy1-17/+0
Its last call site was replaced by mks_tempfile_ts() in 284098f (diff: use tempfile module - 2015-08-12) and there's a good chance mks_tempfile_ts will continue to successfully handle this job. Delete it. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-26Merge branch 'jk/tighten-alloc'Libravatar Junio C Hamano1-0/+3
Update various codepaths to avoid manually-counted malloc(). * jk/tighten-alloc: (22 commits) ewah: convert to REALLOC_ARRAY, etc convert ewah/bitmap code to use xmalloc diff_populate_gitlink: use a strbuf transport_anonymize_url: use xstrfmt git-compat-util: drop mempcpy compat code sequencer: simplify memory allocation of get_message test-path-utils: fix normalize_path_copy output buffer size fetch-pack: simplify add_sought_entry fast-import: simplify allocation in start_packfile write_untracked_extension: use FLEX_ALLOC helper prepare_{git,shell}_cmd: use argv_array use st_add and st_mult for allocation size computation convert trivial cases to FLEX_ARRAY macros use xmallocz to avoid size arithmetic convert trivial cases to ALLOC_ARRAY convert manual allocations to argv_array argv-array: add detach function add helpers for allocating flex-array structs harden REALLOC_ARRAY and xcalloc against size_t overflow tree-diff: catch integer overflow in combine_diff_path allocation ...
2016-02-22harden REALLOC_ARRAY and xcalloc against size_t overflowLibravatar Jeff King1-0/+3
REALLOC_ARRAY inherently involves a multiplication which can overflow size_t, resulting in a much smaller buffer than we think we've allocated. We can easily harden it by using st_mult() to check for overflow. Likewise, we can add ALLOC_ARRAY to do the same thing for xmalloc calls. xcalloc() should already be fine, because it takes the two factors separately, assuming the system calloc actually checks for overflow. However, before we even hit the system calloc(), we do our memory_limit_check, which involves a multiplication. Let's check for overflow ourselves so that this limit cannot be bypassed. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-05Merge branch 'js/fopen-harder' into maintLibravatar Junio C Hamano1-0/+13
Some codepaths used fopen(3) when opening a fixed path in $GIT_DIR (e.g. COMMIT_EDITMSG) that is meant to be left after the command is done. This however did not work well if the repository is set to be shared with core.sharedRepository and the umask of the previous user is tighter. They have been made to work better by calling unlink(2) and retrying after fopen(3) fails with EPERM. * js/fopen-harder: Handle more file writes correctly in shared repos commit: allow editing the commit message even in shared repos
2016-01-20Merge branch 'js/fopen-harder'Libravatar Junio C Hamano1-0/+13
Some codepaths used fopen(3) when opening a fixed path in $GIT_DIR (e.g. COMMIT_EDITMSG) that is meant to be left after the command is done. This however did not work well if the repository is set to be shared with core.sharedRepository and the umask of the previous user is tighter. They have been made to work better by calling unlink(2) and retrying after fopen(3) fails with EPERM. * js/fopen-harder: Handle more file writes correctly in shared repos commit: allow editing the commit message even in shared repos
2016-01-12Merge branch 'sb/submodule-parallel-fetch'Libravatar Junio C Hamano1-2/+18
Add a framework to spawn a group of processes in parallel, and use it to run "git fetch --recurse-submodules" in parallel. Rerolled and this seems to be a lot cleaner. The merge of the earlier one to 'next' has been reverted. * sb/submodule-parallel-fetch: submodules: allow parallel fetching, add tests and documentation fetch_populated_submodules: use new parallel job processing run-command: add an asynchronous parallel child processor sigchain: add command to pop all common signals strbuf: add strbuf_read_once to read without blocking xread: poll on non blocking fds submodule.c: write "Fetching submodule <foo>" to stderr
2016-01-07commit: allow editing the commit message even in shared reposLibravatar Johannes Schindelin1-0/+13
It was pointed out by Yaroslav Halchenko that the file containing the commit message is writable only by the owner, which means that we have to rewrite it from scratch in a shared repository. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-12-21Merge branch 'jk/ident-loosen-getpwuid'Libravatar Junio C Hamano1-12/+0
When getpwuid() on the system returned NULL (e.g. the user is not in the /etc/passwd file or other uid-to-name mappings), the codepath to find who the user is to record it in the reflog barfed and died. Loosen the check in this codepath, which already accepts questionable ident string (e.g. host part of the e-mail address is obviously bogus), and in general when we operate fmt_ident() function in non-strict mode. * jk/ident-loosen-getpwuid: ident: loosen getpwuid error in non-strict mode ident: keep a flag for bogus default_email ident: make xgetpwuid_self() a static local helper
2015-12-16xread: poll on non blocking fdsLibravatar Stefan Beller1-2/+18
The man page of read(2) says: EAGAIN The file descriptor fd refers to a file other than a socket and has been marked nonblocking (O_NONBLOCK), and the read would block. EAGAIN or EWOULDBLOCK The file descriptor fd refers to a socket and has been marked nonblocking (O_NONBLOCK), and the read would block. POSIX.1-2001 allows either error to be returned for this case, and does not require these constants to have the same value, so a portable application should check for both possibilities. If we get an EAGAIN or EWOULDBLOCK the fd must have set O_NONBLOCK. As the intent of xread is to read as much as possible either until the fd is EOF or an actual error occurs, we can ease the feeder of the fd by not spinning the whole time, but rather wait for it politely by not busy waiting. We should not care if the call to poll failed, as we're in an infinite loop and can only get out with the correct read(). Signed-off-by: Stefan Beller <sbeller@google.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-12-10ident: make xgetpwuid_self() a static local helperLibravatar Jeff King1-12/+0
This function is defined in wrapper.c, but nobody besides ident.c uses it. And nobody is likely to in the future, either, as anything that cares about the user's name should be going through the ident code. Moving it here is a cleanup of the global namespace, but it will also enable further cleanups inside ident.c. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-25add xsnprintf helper functionLibravatar Jeff King1-0/+16
There are a number of places in the code where we call sprintf(), with the assumption that the output will fit into the buffer. In many cases this is true (e.g., formatting a number into a large buffer), but it is hard to tell immediately from looking at the code. It would be nice if we had some run-time check to make sure that our assumption is correct (and to communicate to readers of the code that we are not blindly calling sprintf, but have actually thought about this case). This patch introduces xsnprintf, which behaves just like snprintf, except that it dies whenever the output is truncated. This acts as a sort of assert() for these cases, which can help find places where the assumption is violated (as opposed to truncating and proceeding, which may just silently give a wrong answer). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-25write_file_v(): do not leave incomplete line at the endLibravatar Junio C Hamano1-0/+1
All existing callers to this function use it to produce a text file or an empty file, and a new callsite that mimick them must end their payload with a LF. If they forget to do so, the resulting file will end with an incomplete line. Teach write_file_v() to complete the incomplete line, if exists, so that the callers do not have to. With this, the caller-side fix in builtin/am.c becomes unnecessary. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-24write_file(): drop "fatal" parameterLibravatar Junio C Hamano1-4/+24
All callers except three passed 1 for the "fatal" parameter to ask this function to die upon error, but to a casual reader of the code, it was not all obvious what that 1 meant. Instead, split the function into two based on a common write_file_v() that takes the flag, introduce write_file_gently() as a new way to attempt creating a file without dying on error, and make three callers to call it. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-04wrapper: implement xfopen()Libravatar Paul Tan1-0/+21
A common usage pattern of fopen() is to check if it succeeded, and die() if it failed: FILE *fp = fopen(path, "w"); if (!fp) die_errno(_("could not open '%s' for writing"), path); Implement a wrapper function xfopen() for the above, so that we can save a few lines of code and make the die() messages consistent. Helped-by: Jeff King <peff@peff.net> Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de> Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Paul Tan <pyokagan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-04wrapper: implement xopen()Libravatar Paul Tan1-0/+35
A common usage pattern of open() is to check if it was successful, and die() if it was not: int fd = open(path, O_WRONLY | O_CREAT, 0777); if (fd < 0) die_errno(_("Could not open '%s' for writing."), path); Implement a wrapper function xopen() that does the above so that we can save a few lines of code, and make the die() messages consistent. Helped-by: Torsten Bögershausen <tboegi@web.de> Helped-by: Jeff King <peff@peff.net> Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de> Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Paul Tan <pyokagan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-05help.c: wrap wait-only poll() invocation in sleep_millisec()Libravatar Johannes Sixt1-0/+5
We want to use the new function elsewhere in a moment. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-11Merge branch 'nd/multiple-work-trees'Libravatar Junio C Hamano1-0/+31
A replacement for contrib/workdir/git-new-workdir that does not rely on symbolic links and make sharing of objects and refs safer by making the borrowee and borrowers aware of each other. * nd/multiple-work-trees: (41 commits) prune --worktrees: fix expire vs worktree existence condition t1501: fix test with split index t2026: fix broken &&-chain t2026 needs procondition SANITY git-checkout.txt: a note about multiple checkout support for submodules checkout: add --ignore-other-wortrees checkout: pass whole struct to parse_branchname_arg instead of individual flags git-common-dir: make "modules/" per-working-directory directory checkout: do not fail if target is an empty directory t2025: add a test to make sure grafts is working from a linked checkout checkout: don't require a work tree when checking out into a new one git_path(): keep "info/sparse-checkout" per work-tree count-objects: report unused files in $GIT_DIR/worktrees/... gc: support prune --worktrees gc: factor out gc.pruneexpire parsing code gc: style change -- no SP before closing parenthesis checkout: clean up half-prepared directories in --to mode checkout: reject if the branch is already checked out elsewhere prune: strategies for linked checkouts checkout: support checking out into a new working directory ...
2015-02-25Merge branch 'jc/max-io-size-and-ssize-max'Libravatar Junio C Hamano1-1/+15
Our default I/O size (8 MiB) for large files was too large for some platforms with smaller SSIZE_MAX, leading to read(2)/write(2) failures. * jc/max-io-size-and-ssize-max: xread/xwrite: clip MAX_IO_SIZE to SSIZE_MAX
2015-02-12xread/xwrite: clip MAX_IO_SIZE to SSIZE_MAXLibravatar Junio C Hamano1-1/+15
Since 0b6806b9 (xread, xwrite: limit size of IO to 8MB, 2013-08-20), we chomp our calls to read(2) and write(2) into chunks of MAX_IO_SIZE bytes (8 MiB), because a large IO results in a bad latency when the program needs to be killed. This also brought our IO below SSIZE_MAX, which is a limit POSIX allows read(2) and write(2) to fail when the IO size exceeds it, for OS X, where a problem was originally reported. However, there are other systems that define SSIZE_MAX smaller than our default, and feeding 8 MiB to underlying read(2)/write(2) would fail. Make sure we clip our calls to the lower limit as well. Reported-by: Joachim Schmitz <jojo@schmitz-digital.de> Helped-by: Torsten Bögershausen <tboegi@web.de> Helped-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-01wrapper.c: wrapper to open a file, fprintf then closeLibravatar Nguyễn Thái Ngọc Duy1-0/+31
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15wrapper.c: add a new function unlink_or_msgLibravatar Ronnie Sahlberg1-0/+14
This behaves like unlink_or_warn except that on failure it writes the message to its 'err' argument, which the caller can display in an appropriate way or ignore. Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15wrapper.c: remove/unlink_or_warn: simplify, treat ENOENT as successLibravatar Ronnie Sahlberg1-8/+6
Simplify the function warn_if_unremovable slightly. Additionally, change behaviour slightly. If we failed to remove the object because the object does not exist, we can still return success back to the caller since none of the callers depend on "fail if the file did not exist". Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-08Merge branch 'sp/stream-clean-filter'Libravatar Junio C Hamano1-9/+10
When running a required clean filter, we do not have to mmap the original before feeding the filter. Instead, stream the file contents directly to the filter and process its output. * sp/stream-clean-filter: sha1_file: don't convert off_t to size_t too early to avoid potential die() convert: stream from fd to required clean filter to reduce used address space copy_fd(): do not close the input file descriptor mmap_limit: introduce GIT_MMAP_LIMIT to allow testing expected mmap size memory_limit: use git_env_ulong() to parse GIT_ALLOC_LIMIT config.c: add git_env_ulong() to parse environment variable convert: drop arguments other than 'path' from would_convert_to_git()
2014-09-11Merge branch 'nd/large-blobs'Libravatar Junio C Hamano1-16/+52
Teach a few codepaths to punt (instead of dying) when large blobs that would not fit in core are involved in the operation. * nd/large-blobs: diff: shortcut for diff'ing two binary SHA-1 objects diff --stat: mark any file larger than core.bigfilethreshold binary diff.c: allow to pass more flags to diff_populate_filespec sha1_file.c: do not die failing to malloc in unpack_compressed_entry wrapper.c: introduce gentle xmallocz that does not die()
2014-08-28memory_limit: use git_env_ulong() to parse GIT_ALLOC_LIMITLibravatar Steffen Prohaska1-7/+8
GIT_ALLOC_LIMIT limits xmalloc()'s size, which is of type size_t. Better use git_env_ulong() to parse the environment variable, so that the postfixes 'k', 'm', and 'g' can be used; and use size_t to store the limit for consistency. The change to size_t has no direct practical impact, because the environment variable is only meant to be used for our own tests, and we use it to test small sizes. The cast of size in the call to die() is changed to uintmax_t to match the format string PRIuMAX. Signed-off-by: Steffen Prohaska <prohaska@zib.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-26wrapper: add xgetcwd()Libravatar René Scharfe1-0/+8
Add the helper function xgetcwd(), which returns the current directory or dies. The returned string has to be free()d after use. Helped-by: Duy Nguyen <pclouds@gmail.com> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-18wrapper.c: introduce gentle xmallocz that does not die()Libravatar Nguyễn Thái Ngọc Duy1-16/+52
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-10read-cache.c: verify index file before we opportunistically update itLibravatar Yiannis Marangos1-0/+20
Before we proceed to opportunistically update the index (often done by an otherwise read-only operation like "git status" and "git diff" that internally refreshes the index), we must verify that the current index file is the same as the one that we read earlier before we took the lock on it, in order to avoid a possible race. In the example below git-status does "opportunistic update" and git-rebase updates the index, but the race can happen in general. 1. process A calls git-rebase (or does anything that uses the index) 2. process A applies 1st commit 3. process B calls git-status (or does anything that updates the index) 4. process B reads index 5. process A applies 2nd commit 6. process B takes the lock, then overwrites process A's changes. 7. process A applies 3rd commit As an end result the 3rd commit will have a revert of the 2nd commit. When process B takes the lock, it needs to make sure that the index hasn't changed since step 4. Signed-off-by: Yiannis Marangos <yiannis.marangos@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-10wrapper.c: add xpread() similar to xread()Libravatar Yiannis Marangos1-0/+18
It is a common mistake to call read(2)/pread(2) and forget to anticipate that they may return error with EAGAIN/EINTR when the system call is interrupted. We have xread() helper to relieve callers of read(2) from having to worry about it; add xpread() helper to do the same for pread(2). Update the caller in the builtin/index-pack.c and the mmap emulation in compat/. Signed-off-by: Yiannis Marangos <yiannis.marangos@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-11-12typofixes: fix misspelt commentsLibravatar Masanari Iida1-1/+1
Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-10-14wrapper.c: only define gitmkstemps if neededLibravatar Ramsay Jones1-0/+2
When the NO_MKSTEMPS build variable is not set, the gitmkstemps function is dead code. Use a preprocessor conditional to only include the definition when needed. Noticed by sparse. ("'gitmkstemps' was not declared. Should it be static?") Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-08-20xread, xwrite: limit size of IO to 8MBLibravatar Steffen Prohaska1-0/+12
Checking out 2GB or more through an external filter (see test) fails on Mac OS X 10.8.4 (12E55) for a 64-bit executable with: error: read from external filter cat failed error: cannot feed the input to external filter cat error: cat died of signal 13 error: external filter cat failed 141 error: external filter cat failed The reason is that read() immediately returns with EINVAL when asked to read more than 2GB. According to POSIX [1], if the value of nbyte passed to read() is greater than SSIZE_MAX, the result is implementation-defined. The write function has the same restriction [2]. Since OS X still supports running 32-bit executables, the 32-bit limit (SSIZE_MAX = INT_MAX = 2GB - 1) seems to be also imposed on 64-bit executables under certain conditions. For write, the problem has been addressed earlier [6c642a]. Address the problem for read() and write() differently, by limiting size of IO chunks unconditionally on all platforms in xread() and xwrite(). Large chunks only cause problems, like causing latencies when killing the process, even if OS X was not buggy. Doing IO in reasonably sized smaller chunks should have no negative impact on performance. The compat wrapper clipped_write() introduced earlier [6c642a] is not needed anymore. It will be reverted in a separate commit. The new test catches read and write problems. Note that 'git add' exits with 0 even if it prints filtering errors to stderr. The test, therefore, checks stderr. 'git add' should probably be changed (sometime in another commit) to exit with nonzero if filtering fails. The test could then be changed to use test_must_fail. Thanks to the following people for suggestions and testing: Johannes Sixt <j6t@kdbg.org> John Keeping <john@keeping.me.uk> Jonathan Nieder <jrnieder@gmail.com> Kyle J. McKay <mackyle@gmail.com> Linus Torvalds <torvalds@linux-foundation.org> Torsten Bögershausen <tboegi@web.de> [1] http://pubs.opengroup.org/onlinepubs/009695399/functions/read.html [2] http://pubs.opengroup.org/onlinepubs/009695399/functions/write.html [6c642a] commit 6c642a878688adf46b226903858b53e2d31ac5c3 compate/clipped-write.c: large write(2) fails on Mac OS X/XNU Signed-off-by: Steffen Prohaska <prohaska@zib.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-22Merge branch 'tr/fd-gotcha-fixes'Libravatar Junio C Hamano1-1/+1
Two places we did not check return value (expected to be a file descriptor) correctly. * tr/fd-gotcha-fixes: run-command: dup_devnull(): guard against syscalls failing git_mkstemps: correctly test return value of open()
2013-07-12git_mkstemps: correctly test return value of open()Libravatar Dale R. Worley1-1/+1
open() returns -1 on failure, and indeed 0 is a possible success value if the user closed stdin in our process. Fix the test. Signed-off-by: Thomas Rast <trast@inf.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-15config: allow inaccessible configuration under $HOMELibravatar Jonathan Nieder1-4/+10
The changes v1.7.12.1~2^2~4 (config: warn on inaccessible files, 2012-08-21) and v1.8.1.1~22^2~2 (config: treat user and xdg config permission problems as errors, 2012-10-13) were intended to prevent important configuration (think "[transfer] fsckobjects") from being ignored when the configuration is unintentionally unreadable (for example with EIO on a flaky filesystem, or with ENOMEM due to a DoS attack). Usually ~/.gitconfig and ~/.config/git are readable by the current user, and if they aren't then it would be easy to fix those permissions, so the damage from adding this check should have been minimal. Unfortunately the access() check often trips when git is being run as a server. A daemon (such as inetd or git-daemon) starts as "root", creates a listening socket, and then drops privileges, meaning that when git commands are invoked they cannot access $HOME and die with fatal: unable to access '/root/.config/git/config': Permission denied Any patch to fix this would have one of three problems: 1. We annoy sysadmins who need to take an extra step to handle HOME when dropping privileges (the current behavior, or any other proposal that they have to opt into). 2. We annoy sysadmins who want to set HOME when dropping privileges, either by making what they want to do impossible, or making them set an extra variable or option to accomplish what used to work (e.g., a patch to git-daemon to set HOME when --user is passed). 3. We loosen the check, so some cases which might be noteworthy are not caught. This patch is of type (3). Treat user and xdg configuration that are inaccessible due to permissions (EACCES) as though no user configuration was provided at all. An alternative method would be to check if $HOME is readable, but that would not help in cases where the user who dropped privileges had a globally readable HOME with only .config or .gitconfig being private. This does not change the behavior when /etc/gitconfig or .git/config is unreadable (since those are more serious configuration errors), nor when ~/.gitconfig or ~/.config/git is unreadable due to problems other than permissions. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Improved-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-01-11Merge branch 'jn/warn-on-inaccessible-loosen' into maintLibravatar Junio C Hamano1-1/+9
When attempting to read the XDG-style $HOME/.config/git/config and finding that $HOME/.config/git is a file, we gave a wrong error message, instead of treating the case as "a custom config file does not exist there" and moving on. * jn/warn-on-inaccessible-loosen: config: exit on error accessing any config file doc: advertise GIT_CONFIG_NOSYSTEM config: treat user and xdg config permission problems as errors config, gitignore: failure to access with ENOTDIR is ok