| 1 | package util |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "os" |
| 6 | "strconv" |
| 7 | "syscall" |
| 8 | |
| 9 | logging "github.com/ipfs/go-log/v2" |
| 10 | ) |
| 11 | |
| 12 | var log = logging.Logger("ulimit") |
| 13 | |
| 14 | var ( |
| 15 | supportsFDManagement = false |
| 16 | |
| 17 | // getlimit returns the soft and hard limits of file descriptors counts. |
| 18 | getLimit func() (uint64, uint64, error) |
| 19 | // set limit sets the soft and hard limits of file descriptors counts. |
| 20 | setLimit func(uint64, uint64) error |
| 21 | ) |
| 22 | |
| 23 | // minimum file descriptor limit before we complain. |
| 24 | const minFds = 2048 |
| 25 | |
| 26 | // default max file descriptor limit. |
| 27 | const maxFds = 8192 |
| 28 | |
| 29 | // userMaxFDs returns the value of IPFS_FD_MAX. |
| 30 | func userMaxFDs() uint64 { |
| 31 | // check if the IPFS_FD_MAX is set up and if it does |
| 32 | // not have a valid fds number notify the user |
| 33 | if val := os.Getenv("IPFS_FD_MAX"); val != "" { |
| 34 | fds, err := strconv.ParseUint(val, 10, 64) |
| 35 | if err != nil { |
| 36 | log.Errorf("bad value for IPFS_FD_MAX: %s", err) |
| 37 | return 0 |
| 38 | } |
| 39 | return fds |
| 40 | } |
| 41 | return 0 |
| 42 | } |
| 43 | |
| 44 | // ManageFdLimit raise the current max file descriptor count |
| 45 | // of the process based on the IPFS_FD_MAX value. |
| 46 | func ManageFdLimit() (changed bool, newLimit uint64, err error) { |
| 47 | if !supportsFDManagement { |
| 48 | return false, 0, nil |
| 49 | } |
| 50 | |
| 51 | targetLimit := uint64(maxFds) |
| 52 | userLimit := userMaxFDs() |
| 53 | if userLimit > 0 { |
| 54 | targetLimit = userLimit |
| 55 | } |
| 56 | |
| 57 | soft, hard, err := getLimit() |
| 58 | if err != nil { |
| 59 | return false, 0, err |
| 60 | } |
| 61 | |
| 62 | if targetLimit <= soft { |
| 63 | return false, 0, nil |
| 64 | } |
| 65 | |
| 66 | // the soft limit is the value that the kernel enforces for the |
| 67 | // corresponding resource |
| 68 | // the hard limit acts as a ceiling for the soft limit |
| 69 | // an unprivileged process may only set its soft limit to a |
| 70 | // value in the range from 0 up to the hard limit |
| 71 | err = setLimit(targetLimit, targetLimit) |
| 72 | switch err { |
| 73 | case nil: |
| 74 | newLimit = targetLimit |
| 75 | case syscall.EPERM: |
| 76 | // lower limit if necessary. |
| 77 | if targetLimit > hard { |
| 78 | targetLimit = hard |
| 79 | } |
| 80 | |
| 81 | // the process does not have permission so we should only |
| 82 | // set the soft value |
| 83 | err = setLimit(targetLimit, hard) |
| 84 | if err != nil { |
| 85 | err = fmt.Errorf("error setting ulimit without hard limit: %w", err) |
| 86 | break |
| 87 | } |
| 88 | newLimit = targetLimit |
| 89 | |
| 90 | // Warn on lowered limit. |
| 91 | |
| 92 | if newLimit < userLimit { |
| 93 | err = fmt.Errorf( |
| 94 | "failed to raise ulimit to IPFS_FD_MAX (%d): set to %d", |
| 95 | userLimit, |
| 96 | newLimit, |
| 97 | ) |
| 98 | break |
| 99 | } |
| 100 | |
| 101 | if userLimit == 0 && newLimit < minFds { |
| 102 | err = fmt.Errorf( |
| 103 | "failed to raise ulimit to minimum %d: set to %d", |
| 104 | minFds, |
| 105 | newLimit, |
| 106 | ) |
| 107 | break |
| 108 | } |
| 109 | default: |
| 110 | err = fmt.Errorf("error setting: ulimit: %w", err) |
| 111 | } |
| 112 | |
| 113 | return newLimit > 0, newLimit, err |
| 114 | } |